tag:theconversation.com,2011:/africa/topics/grid-energy-storage-16710/articlesGrid energy storage – The Conversation2022-01-19T13:45:34Ztag:theconversation.com,2011:article/1744462022-01-19T13:45:34Z2022-01-19T13:45:34ZBatteries get hyped, but pumped hydro provides the vast majority of long-term energy storage essential for renewable power – here’s how it works<figure><img src="https://images.theconversation.com/files/440326/original/file-20220111-21166-10rrp9s.jpg?ixlib=rb-1.1.0&rect=268%2C0%2C4255%2C2582&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The U.S. has thousands of lakes and reservoirs that could be paired for pumped hydro storage without the need for rivers.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/reservoir-storage-basin-of-pumped-storage-plant-royalty-free-image/1276487342?adppopup=true">Ollo via Getty Images</a></span></figcaption></figure><p>To cut U.S. greenhouse gas emissions in <a href="https://www.whitehouse.gov/briefing-room/statements-releases/2021/04/22/fact-sheet-president-biden-sets-2030-greenhouse-gas-pollution-reduction-target-aimed-at-creating-good-paying-union-jobs-and-securing-u-s-leadership-on-clean-energy-technologies/">half within a decade</a>, the Biden administration’s goal, the U.S. is going to need a lot more solar and wind power generation, and lots of cheap energy storage.</p>
<p>Wind and solar power vary over the course of a day, so energy storage is essential to provide a continuous flow of electricity. But today’s batteries are typically quite small and store enough energy for only a few hours of electricity. To rely more on wind and solar power, the U.S. will need more overnight and longer-term storage as well.</p>
<p>While battery innovations <a href="https://www.energy.gov/articles/secretary-granholm-announces-new-goal-cut-costs-long-duration-energy-storage-90-percent">get a lot of attention</a>, there’s a simple, proven long-term storage technique that’s been used in the U.S. since the 1920s.</p>
<p>It’s called <a href="https://www.energy.gov/eere/water/pumped-storage-hydropower">pumped hydro energy storage</a>. It involves pumping water uphill from one reservoir to another at a higher elevation for storage, then, when power is needed, releasing the water to flow downhill through turbines, generating electricity on its way to the lower reservoir.</p>
<figure class="align-center ">
<img alt="Illustration of two open- and closed-loop hydro storage systems. Closed-loop systems use two reservoirs rather than running water." src="https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=349&fit=crop&dpr=1 600w, https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=349&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=349&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=439&fit=crop&dpr=1 754w, https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=439&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/439528/original/file-20220105-23-1pfjjmh.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=439&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Two types of pumped-storage hydropower; one doesn’t require a river.</span>
<span class="attribution"><a class="source" href="https://www.pnnl.gov/news-media/open-or-closed-pumped-storage-hydropower-rise">NREL</a></span>
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<p>Pumped hydro storage is often overlooked in the U.S. because of concern about hydropower’s impact on rivers. But what many people don’t realize is that most of the best hydro storage sites aren’t on rivers at all.</p>
<p>We created a <a href="https://nationalmap.prod.saas.terria.io/#share=s-tPEnZ4T5NRAYIiLS0E3ftvcAzb">world atlas</a> of potential sites for closed-looped pumped hydro – systems that don’t include a river – and found 35,000 paired sites in the U.S. with good potential. While many of these sites, which we located by satellite, are in rugged terrain and may be unsuitable for geological, hydrological, economic, environmental or social reasons, we estimate that only a few hundred sites are needed to <a href="https://doi.org/10.1088/2516-1083/abeb5b">support a 100% renewable U.S. electricity system</a>.</p>
<h2>Why wind and solar need long-term storage</h2>
<p>To function properly, power grids must be able to match the incoming electricity supply to electricity demand in real time or they risk shortages or overloads.</p>
<p><a href="https://ieeexplore.ieee.org/document/8836526">There are several techniques</a> that grid managers can use to keep that balance with variable sources like wind and solar. These include sharing power across large regions via interstate high-voltage transmission lines, managing demand – and using energy storage.</p>
<figure class="align-center ">
<img alt="Aerial view of a pumped hydro project's two reservoirs and solar array on a dry landscape" src="https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/439826/original/file-20220107-13-10vq0yv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Kidston pumped hydro project in Australia uses an old gold mine for reservoirs.</span>
<span class="attribution"><a class="source" href="https://genexpower.com.au/250mw-kidston-pumped-storage-hydro-project/">Genex Power</a></span>
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<p>Batteries deployed in homes, power stations and electric vehicles are preferred for energy storage times up to a few hours. They’re adept at managing the rise of solar power midday when the sun is overhead and releasing it when power demand peaks in the evenings.</p>
<p>Pumped hydro, on the other hand, allows for larger and longer storage than batteries, and that is essential in a wind- and solar-dominated electricity system. It is also cheaper for overnight and longer-term storage.</p>
<h2>Off-river pumped hydro energy storage</h2>
<p>In 2021, the U.S. had <a href="https://www.energy.gov/sites/prod/files/2021/01/f82/us-hydropower-market-report-full-2021.pdf">43 operating pumped hydro plants</a> with a total generating capacity of <a href="https://www.hydro.org/wp-content/uploads/2021/09/2021-Pumped-Storage-Report-NHA.pdf">about 22 gigawatts</a> and an energy storage capacity of 553 gigawatt-hours. They make up 93% of utility-scale storage in the country. Globally, <a href="https://doi.org/10.1088/2516-1083/abeb5b">pumped hydro’s share</a> of energy storage <a href="https://sandia.gov/ess-ssl/gesdb/public/">is even higher</a> – about <a href="https://doi.org/10.1088/2516-1083/abeb5b">99% of energy storage volume</a>.</p>
<p>Pump hydro projects <a href="https://www.hcn.org/issues/54.1/north-renewable-energy-cultural-resources-are-not-a-renewable-thing-for-us">can be controversial</a>, <a href="https://www.azcentral.com/story/news/local/arizona-environment/2021/08/05/2-little-colorado-river-dam-projects-have-been-withdrawn/5408667001/">particularly when they involve dams on rivers</a> that flood land to create new reservoirs and can affect ecosystems.</p>
<p>Creating closed-loop systems that use pairs of existing lakes or reservoirs instead of rivers would avoid the need for new dams. A project planned in Bell County, Kentucky, for example, uses an <a href="https://www.hydroreview.com/hydro-industry-news/rye-development-to-build-lewis-ridge-pumped-storage-project-in-kentucky-u-s/">old coal strip mine</a>. Little additional land <a href="https://doi.org/10.1088/2516-1083/abeb5b">is needed except for transmission lines</a>.</p>
<figure class="align-center ">
<img alt="Satellite image showing potential pairings of reservoirs in a mountain area." src="https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=540&fit=crop&dpr=1 600w, https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=540&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=540&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=678&fit=crop&dpr=1 754w, https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=678&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/439529/original/file-20220105-19-1oo8bzw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=678&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Examples from the atlas of off-river reservoirs with the potential to be paired for pumped hydro near Castle Rock, Colorado.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1016/j.joule.2020.11.015">Andrew Blakers</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
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<p>An off-river pumped hydro system comprises a pair of reservoirs spaced several miles apart with an altitude difference of 200-800 meters (about 650-2,600 feet) and connected with pipes or tunnels. The reservoirs can be new or use <a href="https://www.genexpower.com.au/250mw-kidston-pumped-storage-hydro-project.html">old mining sites</a> or <a href="https://www.snowyhydro.com.au/snowy-20/about/">existing lakes or reservoirs</a>.</p>
<p>On sunny or windy days, water is pumped to the upper reservoir. At night, the water flows back down through the turbines to recover the stored energy.</p>
<p>A pair of 250-acre reservoirs with an altitude difference of 600 meters (1,969 feet) and 20-meter depth (65 feet) can store 24 gigawatt-hours of energy, meaning the system could supply 1 gigawatt of power for 24 hours, <a href="https://doi.org/10.1088/2516-1083/abeb5b">enough for a city of a million people</a>.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/dvLBE0HcitQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>The water can cycle between upper and lower reservoirs for a hundred years or more. <a href="https://doi.org/10.1029/2010WR009889">Evaporation suppressors</a> – small objects floating on the water to trap humid air – can help reduce water evaporation. In all, the amount of water needed to support a 100% renewable electricity system is about <a href="https://doi.org/10.1088/2516-1083/abeb5b">3 liters per person per day</a>, equivalent to 20 seconds of a morning shower. This is <a href="https://doi.org/10.1021/acs.est.8b00139">one-tenth</a> of the water evaporated per person per day in the cooling systems of U.S. fossil fuel power stations. </p>
<h2>Storage to support 100% renewables</h2>
<p>Little pumped storage has been built in the U.S. in recent years because there hasn’t been much need, but that’s changing. </p>
<p>In 2020, about <a href="https://www.powerengineeringint.com/renewables/renewable-energy-account-for-78-of-us-capacity-additions-in-2020/">three-quarters</a> of all new power capacity built was either solar photovoltaics or wind power. Their costs have been falling, making them <a href="https://www.lazard.com/perspective/levelized-cost-of-energy-levelized-cost-of-storage-and-levelized-cost-of-hydrogen/">cheaper to build in many areas</a> than fossil fuels.</p>
<p>Australia is <a href="https://www.dropbox.com/s/wprwd9p3mjrm6z8/RE%20update.docx?dl=0">installing solar and wind</a> three times faster per capita than the U.S. and is already facing the need for <a href="https://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/pubs/rp/rp2021/AustralianElectricityOptionsPumpedHydro">mass storage</a>. It has <a href="https://www.snowyhydro.com.au/snowy-20/about/">two systems</a> <a href="https://www.genexpower.com.au/250mw-kidston-pumped-storage-hydro-project.html">under construction</a> that are designed to have more energy storage than all the utility batteries in the world put together; another dozen are under serious consideration. None involve new dams on rivers. The annual operating cost is low, and the working fluid is water rather than battery chemicals.</p>
<p>Shifting electricity to renewable energy and then electrifying vehicles and heating can eliminate most human-caused greenhouse gas emissions. The U.S. has vast potential for off-river pumped hydro storage to help this happen, and it will need it as wind and solar power expand.</p>
<p>[<em>More than 140,000 readers get one of The Conversation’s informative newsletters.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-140K">Join the list today</a>.]</p><img src="https://counter.theconversation.com/content/174446/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Blakers receives funding from the Australian Renewable Energy Agency</span></em></p><p class="fine-print"><em><span>Bin Lu receives funding from the Australian Renewable Energy Agency. </span></em></p><p class="fine-print"><em><span>Matthew Stocks receives funding from ARENA for the Australian pumped hydro analysis.</span></em></p>A team of researchers found 35,000 pairs of existing reservoirs, lakes and old mines in the US that could be turned into long-term energy storage – and they don’t need dams on rivers.Andrew Blakers, Professor of Engineering, Australian National UniversityBin Lu, Research Fellow, Australian National UniversityMatthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1557132021-02-24T21:04:53Z2021-02-24T21:04:53ZWhy Canada should invest in ‘macrogrids’ for greener, more reliable electricity<figure><img src="https://images.theconversation.com/files/386276/original/file-20210224-9618-t4dv5u.jpg?ixlib=rb-1.1.0&rect=83%2C71%2C3861%2C2604&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Water rushes through the Carillon Hydro electric dam in Québec.</span> <span class="attribution"><span class="source">THE CANADIAN PRESS/Ryan Remiorz</span></span></figcaption></figure><p>As the recent disaster in Texas showed, climate change requires electricity utilities <a href="https://electricity.ca/wp-content/uploads/2016/02/Adapting_to_Climate_Change-State_of_Play_and_Recommendations_for_the_Electricity_Sector_in_Canada.pdf">to prepare for extreme events</a>. This “<a href="https://www.youtube.com/channel/UCi6RkdaEqgRVKi3AzidF4ow">global weirding</a>” leads to more intense storms, higher wind speeds, heatwaves and droughts that can threaten the performance of electricity systems.</p>
<p>The electricity sector must adapt to this changing climate while also playing a central role in mitigating climate change. Greenhouse gas emissions can be reduced <a href="https://climatechoices.ca/reports/canadas-net-zero-future/">a number of ways</a>, but the electricity sector is expected to play a central role in decarbonization. Zero-emissions electricity can be used to electrify transportation, heating and industry and help achieve emissions reduction in these sectors. </p>
<p>Enhancing long-distance transmission is viewed as a cost-effective way to enable a <a href="https://environmenthalfcentury.princeton.edu/sites/g/files/toruqf331/files/2020-12/Princeton_NZA_Interim_Report_15_Dec_2020_FINAL.pdf">clean and reliable</a> <a href="https://www.vibrantcleanenergy.com/wp-content/uploads/2020/10/EIC-Transmission-Decarb.pdf">power grid</a>, and to lower the cost of meeting our climate targets. Now is the time to strengthen transmission links in Canada. </p>
<h2>Insurance for climate extremes</h2>
<p>An early lesson from the <a href="https://www.texastribune.org/2021/02/18/texas-power-outages-ercot/">Texas power outages</a> is that extreme conditions can lead to failures across all forms of power supply. The state lost the capacity to generate electricity from natural gas, coal, nuclear and wind simultaneously. But it also lacked transmission connections to other electricity systems that could have bolstered supply. </p>
<p>Long-distance transmission offers the opportunity to escape the correlative clutch of extreme weather, by accessing energy and spare capacity in areas not beset by the same weather patterns. For example, while Texas was in its deep freeze, relatively balmy conditions in California meant there was a surplus of electricity generation capability in that region — but no means to get it to Texas. Building new transmission lines and connections across broader regions can act as an insurance policy, providing a back-up for regions hit by the crippling effects of climate change. </p>
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<img alt="A transmission tower crumpled under the weight of ice." src="https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=434&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=434&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=434&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=546&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=546&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386277/original/file-20210224-15-1sy71na.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=546&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The 1998 Quebec ice storm left 3.5 million Quebecers and a million Ontarians, as well as thousands in in New Brunswick, without power.</span>
<span class="attribution"><span class="source">CP Photo/Robert Galbraith</span></span>
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<p>Transmission is also vulnerable to climate disruptions, such as crippling ice storms that leave wires temporarily inoperable. This may mean using stronger poles when building transmission, or <a href="https://www.volts.wtf/p/transmission-fortnight-burying-power">burying major high-voltage transmission links</a>. </p>
<p>In any event, more transmission links between regions can <a href="https://doi.org/10.1109/JSYST.2017.2700791">improve resilience</a> by co-ordinating supply across larger regions. Well-connected grids that are larger than the areas disrupted by weather systems can be more resilient to climate extremes.</p>
<h2>Lowering the cost of clean power</h2>
<p>Adding more transmission can also play a role in mitigating climate change. <a href="https://doi.org/10.1016/j.joule.2020.11.013">Numerous</a> <a href="https://www.vibrantcleanenergy.com/wp-content/uploads/2020/10/EIC-Transmission-Decarb.pdf">studies</a> have found that <a href="https://doi.org/10.1038/nclimate2921">building a larger transmission grid</a> allows for greater shares of renewables onto the grid, ultimately lowering the overall cost of electricity.</p>
<p>In a recent study, two of us looked at the role transmission could play in <a href="https://doi.org/10.1016/j.enpol.2017.10.040">lowering greenhouse gas emissions in Canada’s electricity sector</a>. We found the cost of reducing greenhouse gas emissions is lower when new or enhanced transmission links can be built between provinces. </p>
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<img alt="ALT TK" src="https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=514&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=514&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=514&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=646&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=646&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385974/original/file-20210223-24-1wt2n2c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=646&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Average cost increase to electricity in Canada at different levels of decarbonization, with new transmission (black) and without new transmission (red). New transmission lowers the cost of reducing greenhouse gas emissions.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1016/j.enpol.2017.10.040">(Authors)</a>, <span class="license">Author provided</span></span>
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<p>Much of the value of transmission in these scenarios comes from linking high-quality wind and solar resources with flexible zero-emission generation that can produce electricity on demand. In Canada, our system is dominated by hydroelectricity, but most of this hydro capacity is located in five provinces: British Columbia, Manitoba, Ontario, Québec and Newfoundland and Labrador. </p>
<p>In the west, Alberta and Saskatchewan are great locations for building low-cost wind and solar farms. Enhanced interprovincial transmission would allow Alberta and Saskatchewan to build more variable wind and solar, with the assurance that they could receive backup power from B.C. and Manitoba when the wind isn’t blowing and the sun isn’t shining. </p>
<p>When wind and solar are plentiful, the flow of low cost energy can reverse to allow B.C. and Manitoba the opportunity to better manage their hydro reservoir levels. Provinces can only benefit from trading with each other if we have the infrastructure to make that trade possible.</p>
<p>A <a href="https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3742136">recent working paper</a> examined the role that new transmission links could play in decarbonizing the B.C. and Alberta electricity systems. We again found that enabling greater electricity trade between B.C. and Alberta can reduce the cost of deep cuts to greenhouse gas emissions by billions of dollars a year. Although we focused on the value of the <a href="https://www.sitecproject.com/">Site C project</a>, the analysis showed that new transmission would offer benefits of much greater value than a single hydroelectric project. </p>
<figure class="align-center ">
<img alt="TK" src="https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=369&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=369&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=369&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=464&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=464&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385975/original/file-20210223-22-13n1wiz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=464&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The value of enabling new transmission links between Alberta and B.C. as greenhouse gas emissions reductions are pursued.</span>
<span class="attribution"><span class="source">(Authors)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Getting transmission built</h2>
<p>With the benefits that enhanced electricity transmission links can provide, one might think new projects would be a slam dunk. But there are barriers to getting projects built. </p>
<p>First, electricity grids in Canada are managed at the provincial level, most often by Crown corporations. Decisions by the Crowns are influenced not simply by economics, but also by political considerations. If a transmission project enables greater imports of electricity to Saskatchewan from Manitoba, it raises a flag about lost economic development opportunity within Saskatchewan. Successful transmission agreements need to ensure a two-way flow of benefits. </p>
<p>Second, transmission can be expensive. On this front, the Canadian government could open up the purse strings to fund new transmission links between provinces. It has already <a href="https://www.canada.ca/en/office-infrastructure/news/2020/02/transmission-line-to-reduce-greenhouse-gas-emissions-and-create-more-reliable-power-supply.html">shown a willingness to do so</a>. </p>
<p>Lastly, transmission lines are long linear projects, not unlike pipelines. Siting transmission lines can be contentious, <a href="https://www.sierraclub.org/massachusetts/canadian-hydropower">even when they are delivering zero-emissions electricity</a>. Using infrastructure corridors, such as <a href="https://www.volts.wtf/p/transmission-fortnight-burying-power">existing railway right of ways</a> or the proposed <a href="https://www.canadiancorridor.ca/">Canadian Northern Corridor</a>, could help better facilitate co-operation between regions and reduce the risks of siting transmission lines.</p>
<p>If Canada can address these barriers to transmission, we should find ourselves in an advantageous position, where we are more resilient to climate extremes and have achieved a lower-cost, zero-emissions electricity grid.</p><img src="https://counter.theconversation.com/content/155713/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brett Dolter receives funding from The Social Sciences and Humanities Research Council and the Energy Modelling Initiative (<a href="https://emi-ime.ca/">https://emi-ime.ca/</a>). Brett Dolter previously provided consulting services to SaskPower. </span></em></p><p class="fine-print"><em><span>Blake Shaffer has received funding from Natural Resources Canada, and has provided policy advisory services for the Governments of B.C., Alberta, and Canada. He previously held senior energy trading positions at Transalta Corporation and BC Hydro. </span></em></p><p class="fine-print"><em><span>Nicholas Rivers receives funding from the Social Sciences and Humanities Research Council. </span></em></p><p class="fine-print"><em><span>G. Kent Fellows does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The electricity sector is expected to play a key role in Canada’s push to net-zero emissions. Enhancing long-distance transmission can be lower the cost of providing clean and reliable electricity.Brett Dolter, Assistant Professor, Economics, University of ReginaBlake Shaffer, Assistant professor, Economics and School of Public Policy, University of CalgaryG. Kent Fellows, Research associate, public policy, University of CalgaryNicholas Rivers, Canada Research Chair in Climate and Energy Policy, L’Université d’Ottawa/University of OttawaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1448642020-09-07T20:12:41Z2020-09-07T20:12:41ZAussie invention could save old coal stations by running them on zero-emissions ‘Lego’ blocks<figure><img src="https://images.theconversation.com/files/356667/original/file-20200907-115024-5rwew2.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3000%2C1684&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Authors provided</span></span></figcaption></figure><p>As climate change worsens, the future of fossil fuel jobs and infrastructure is uncertain. But a new energy storage technology invented in Australia could enable coal-fired power stations to run entirely emissions-free.</p>
<p>The novel material, called miscibility gap alloy (<a href="https://www.mgathermal.com/publications">MGA</a>), stores energy in the form of heat. MGA is housed in small blocks of blended metals, which receive energy generated by renewables such as solar and wind.</p>
<p>The energy can then be used as an alternative to coal to run steam turbines at coal-fired power stations, without producing emissions. Stackable like Lego, MGA blocks can be added or removed, scaling electricity generation up or down to meet demand.</p>
<p>MGA blocks are a fraction of the cost of a rival energy storage technology, lithium-ion batteries. Our invention has been <a href="https://link.springer.com/chapter/10.1007%2F978-3-319-69844-1_48">proven</a> in the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0038092X19304220?via%3Dihub">lab</a> – now we are moving to the next phase of proving it in the real world.</p>
<figure class="align-center ">
<img alt="Steam billows from a coal-fired power station" src="https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/356669/original/file-20200907-114278-1w0c69l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">MGA blocks promise to give new life to old coal stations.</span>
<span class="attribution"><span class="source">Themba Hadebe/AP</span></span>
</figcaption>
</figure>
<h2>Why energy storage is important</h2>
<p>Major renewable energy sources such as solar and wind power are “intermittent”. In other words, they only produce energy when the sun is shining and the wind is blowing. Sometimes they produce more energy than is needed, and other times, less.</p>
<p>So moving to 100% renewable electricity requires the energy to be “dispatchable” – stored and delivered on demand. Some forms of storage, such as <a href="https://about.bnef.com/blog/behind-scenes-take-lithium-ion-battery-prices">lithium-ion batteries</a>, are relatively expensive and can only store energy for short periods. Others, such as hydro-electric power, can store energy for longer periods, but are site-dependent and can’t just be built anywhere.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/45-000-renewables-jobs-are-australias-for-the-taking-but-how-many-will-go-to-coal-workers-141531">45,000 renewables jobs are Australia’s for the taking – but how many will go to coal workers?</a>
</strong>
</em>
</p>
<hr>
<p>If our electricity grid is to become emissions-free, we need an energy storage option that’s both affordable and versatile enough to be rolled out at massive scale - providing six to eight hours of dispatchable power every night. </p>
<p>MGAs store energy for a day to a week. This fills a “middle” time frame between batteries and hydro-power, and allows intermittent renewable energy to be dispatched when needed.</p>
<figure class="align-center ">
<img alt="Researchers Alex Post and Erich Kisi, look at a MGA block." src="https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/356670/original/file-20200907-111081-1h20soe.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Researchers Alex Post and Erich Kisi. The company is looking to built a pilot manufacturing plant in NSW.</span>
<span class="attribution"><span class="source">Authors provided</span></span>
</figcaption>
</figure>
<h2>How our invention works</h2>
<p>In the next <a href="https://www.energynetworks.com.au/news/energy-insider/the-demise-of-coal/#:%7E:text=Share%3A,%2Dintensive%20coal%2Dfired%20generation.&text=Since%202016%2C%202.8%20GW%20of,end%20of%20its%20productive%20life">two decades,</a> many coal-fired power stations around the world will retire or be decommissioned, including <a href="https://www.theguardian.com/environment/2019/dec/12/almost-two-thirds-of-australias-coal-fired-generation-will-be-out-by-2040-aemo-says">in Australia</a>. Our proposed storage may mean power stations could be repurposed, retaining infrastructure and preventing job losses.</p>
<p>For coal stations to use our technology, the furnace and boiler must be removed and replaced by a storage unit containing MGA blocks.</p>
<p>MGA blocks are 20cm x 20cm x 16cm. They essentially comprise a blend of metals – some that melt when heated, and others that don’t. Think of a block as like a choc-chip muffin heated in a microwave. The muffin consists of a cake component, which holds everything in shape when heated, and the choc chips, which melt.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/japan-is-closing-its-old-dirty-power-plants-and-thats-bad-news-for-australias-coal-exports-144452">Japan is closing its old, dirty power plants – and that's bad news for Australia's coal exports</a>
</strong>
</em>
</p>
<hr>
<p>The blocks don’t just store energy – they heat water to create steam. In an old coal plant, this steam can be used to run turbines and generators to produce electricity, rather than burning coal to produce the same effect.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/bt-Ux48Aohw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Courtesy University of Newcastle.</span></figcaption>
</figure>
<p>To create the steam, the blocks can be designed with internal tubing, through which water is pumped and boiled. Alternatively, the blocks can interact with a heat exchanger – a specially designed system to heat the water. </p>
<p>Old coal plants could run on renewable energy that would otherwise be switched off during periods of oversupply in the middle of the day (in the case of solar) or times of high wind (wind energy).</p>
<p>Our research <a href="https://www.rees-journal.org/articles/rees/full_html/2017/01/rees170037s/rees170037s.html">has shown</a> the blocks are a fraction the cost of a lithium battery of the same size, yet produce the same amount of energy.</p>
<figure class="align-center ">
<img alt="Coal worker" src="https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/356781/original/file-20200907-14-2qzvko.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The technology may help prevent job losses in the coal industry.</span>
<span class="attribution"><span class="source">KYDPL KYODO/AP</span></span>
</figcaption>
</figure>
<h2>Proving MGA blocks in the real world</h2>
<p>Our team perfected the novel material through research at the University of Newcastle between 2010 and 2018. Last year we formed a company, MGA Thermal, and are focused on commercialising the technology and conducting real-world projects. </p>
<p>In July this year, MGA Thermal received a A$495,000 grant from the federal Department of Industry, Innovation and Science, to establish a pilot manufacturing plant in Newcastle, New South Wales. This project is due to start operating in the second half of next year. The goal is to begin manufacturing a commercial quantity of MGA blocks economically, at scale, for large demonstration projects. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/yes-carbon-emissions-fell-during-covid-19-but-its-the-shift-away-from-coal-that-really-matters-138611">Yes, carbon emissions fell during COVID-19. But it's the shift away from coal that really matters</a>
</strong>
</em>
</p>
<hr>
<p>MGA Thermal have partnered with a Swiss company, E2S Power AG, to test the technology in the rapidly changing coal-fired power industry in Europe. Beginning next year, the testing will include retrofitting a functioning coal power plant with MGA storage. This will also verify the economic case for the technology.</p>
<p>We are aiming for a cost of storage of A$50 per kilowatt hour, including all surrounding infrastructure. Currently, lithium-ion batteries cost <a href="https://about.bnef.com/blog/behind-scenes-take-lithium-ion-battery-prices">around A$200 per kilowatt hour</a>, with added costs if energy is to be exported to the electricity grid. </p>
<p>So what are the downfalls? Well, MGA does have a much slower response time than batteries. Batteries respond in milliseconds and are excellent at filling short spikes or dips in supply (such as from wind turbines). Meanwhile MGA storage has a response time above 15 minutes, but does have much longer storage capacity. </p>
<p>A combination of all three options – batteries, MGA/thermal storage and hydro – would provide large-scale energy storage that can still respond quickly to fluctuating renewable supply.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/y3uwcBLBv-o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Courtesy University of Newcastle.</span></figcaption>
</figure>
<h2>Safe and recyclable</h2>
<p>MGA blocks are safe and non-toxic – there is no risk of explosion or leakage, unlike some other fuels.</p>
<p>The blocks can also be recycled. They are expected to last 25-30 years, then can be easily separated into their individual materials - to be made into new blocks, or recycled as raw materials for other uses. </p>
<p>Like any new technology, MGA blocks must be financially proven before they’re accepted by industry and used widely in commercial projects. The first full-scale demonstrations of the technology are on the horizon. If successful, they could allow coal-fired power plants to be used cleanly, and provide hope for the future of coal workers.</p><img src="https://counter.theconversation.com/content/144864/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Erich Kisi owns shares in MGA Thermal Pty Ltd.
He has received funding from the Australian Research Council and the Accelerating Commercialisation program of the federal Department of Industry, Science, Energy and Resources. </span></em></p><p class="fine-print"><em><span>Alex Post works for and owns shares in MGA Thermal. He has received funding from the Accelerating Commercialisation program of the federal Department of Industry, Science, Energy and Resources.</span></em></p>The blocks can be used to run steam turbines at power stations as a clean alternative to burning coal, and at a fraction of the price of storing energy in batteries.Erich Kisi, Professor of Engineering , University of NewcastleAlexander Post, Conjoint Lecturer, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1430532020-07-27T12:51:23Z2020-07-27T12:51:23ZThe UK plans to build huge batteries to store renewable energy – but there’s a much cheaper solution<figure><img src="https://images.theconversation.com/files/349604/original/file-20200727-35-1vxbkkk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/concept-energy-storage-system-renewable-photovoltaics-1075034975">Petrmalink/Shutterstock</a></span></figcaption></figure><p>The UK electricity system is undergoing significant and rapid change. It has the world’s <a href="https://www.gov.uk/government/news/battery-storage-boost-to-power-greener-electricity-grid">largest installed capacity</a> of offshore wind, has <a href="https://www.theguardian.com/business/2020/jun/02/uk-electricity-coal-free-for-first-month-ever">effectively stopped</a> generating electricity from coal, and has recorded a <a href="https://www.gov.uk/government/news/battery-storage-boost-to-power-greener-electricity-grid">20% drop</a> in demand since the start of the COVID-19 pandemic. </p>
<p>However, this transition from traditional, reliable coal to weather-dependent wind and solar generation brings with it increasing challenges to match electrical supply and demand at every instant. This is where large grid-scale energy storage systems could help regulate and buffer supply and demand, and improve grid control.</p>
<p>The UK government <a href="https://www.theguardian.com/business/2020/jul/14/government-hopes-cut-in-red-tape-will-triple-uk-battery-capacity">recently announced</a> the removal of planning barriers to building energy storage projects over 50MW in England and 350MW in Wales. This, the government feels, will enable the creation of significant new energy storage capacity. The UK currently has 1GW of operational battery storage units and an <a href="https://marketresearch.solarmedia.co.uk/products/uk-battery-storage-project-database-report">additional 13.5GW</a> of battery projects under development at the planning stage. </p>
<p>This intervention by the government creates a planning environment that could enable the UK to <a href="https://www.nationalgrideso.com/sites/eso/files/documents/fes-2019.pdf">reach its target</a> of net zero carbon emissions by 2050. This could happen with either a high proportion of large-scale, centralised renewable generation, or with more of a priority on smaller community schemes such as locally owned wind turbines and solar panels. Batteries will, in particular, contribute significantly to the grid regulation of a further 30GW of offshore wind by 2030 (to achieve the UK target of <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/853886/Queen_s_Speech_December_2019_-_background_briefing_notes.pdf">40GW of offshore wind</a> by that year).</p>
<p>But pursuing ever larger, stationary battery systems may not be the optimal solution for the UK to have a renewable energy future. Instead, the answer could lie in the country’s garages and car parks.</p>
<p>As the UK has moved from fossil fuel to renewable energy electricity generation, <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/875485/2019_UK_greenhouse_gas_emissions_provisional_figures_statistical_release.pdf">CO₂ emissions</a> from the energy supply sector have fallen from over 40% of the UK total in 1990 to 25% in 2019. This means the transport sector is now the largest emitter, producing a third of all UK CO₂ emissions.</p>
<p>This has led to a growing focus on the introduction of plug-in hybrid and all-electric vehicles. As just <a href="https://www.nextgreencar.com/electric-cars/statistics/">one in ten</a> cars sold in the UK fall into the these categories, there is still some way to go to reducing the impact of petrol and diesel vehicles. Significantly more infrastructure is needed to support them, and their growing popularity increases the amount of electricity that the grid needs to provide, <a href="https://www.ofgem.gov.uk/data-portal/electricity-generation-mix-quarter-and-fuel-source-gb">one-third of which</a> is still produced from natural gas.</p>
<figure class="align-center ">
<img alt="Smiling man plugs in electric car." src="https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/349608/original/file-20200727-19-1c4tq88.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Electric vehicles could be used to store excess energy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/smiling-man-unplugging-charger-car-670589932">Dmytro Zinkevych/Shutterstock</a></span>
</figcaption>
</figure>
<p>However, electric vehicles could also help with making electricity production greener. When an electric vehicle is plugged in for re-charging, it is effectively enabling the electricity grid to access its battery. When you have many vehicles all plugged in at once, they create a very large aggregated battery store. This is a concept known as <a href="https://www.drivingelectric.com/your-questions-answered/324/what-vehicle-grid-v2g-charging">vehicle-to-grid</a> (V2G), and could create a much larger and cheaper alternative energy store than stationary large battery systems. </p>
<p>There are <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/800502/vehicle-licensing-statistics-2018.pdf">38.2m licensed vehicles</a> in the UK, including some 31.5m cars. If these were all battery electric vehicles (each storing an average of 50kWh of energy and connected via a 7kW charger), this could create a nationwide distributed mega battery with a capacity of 220.5GW. This would be over 15 times the size of the currently planned large battery storage.</p>
<h2>Cheaper option</h2>
<p>The costs of this aggregated battery would also be much easier to bear as individual vehicle owners would purchase the cars and batteries, instead of government and private investors having to spend millions on big projects. The cost of electric vehicle batteries has fallen some 87% over the last ten years to <a href="https://about.bnef.com/blog/battery-pack-prices-fall-as-market-ramps-up-with-market-average-at-156-kwh-in-2019/">an average of US$156/kWh</a> (£123/kWh), and is on a trajectory to reach around US$100/kWh by 2023.</p>
<p>Large grid-scale stationary battery system costs are <a href="https://publications.jrc.ec.europa.eu/repository/bitstream/JRC113360/kjna29440enn.pdf">at least double</a> this amount. This is because civil engineering works, cabling, enclosures, power electronics and even air conditioning systems for regulating battery temperature are all required for large stationary battery systems. </p>
<p>Vehicle-to-grid storage is still a nascent concept. It requires dedicated two-way charging equipment that can also communicate with the vehicles, as well high-level aggregator control systems. However all of this technology exists. </p>
<p>Indeed there are a <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/681321/Innovation_in_Vehicle-To-Grid__V2G__Systems_-_Real-World_Demonstrators_-_Competition_Results.pdf">range of V2G demonstrator</a> projects within the UK. Nissan, in particular, has embraced this technology and already offers a more limited_ <a href="https://chargedevs.com/newswire/nissan-australia-touts-leaf-v2h-capabilities-disses-tesla-battery-project/">vehicle-to-home</a> (V2H) system that lets people use their cars to store energy from rooftop solar panels until it is needed in the home at night.</p>
<p>So while the UK government is correct that the national grid needs more energy storage to support the shift to further renewable energy generation, a focus on building large, expensive batteries isn’t necessarily the answer. Instead, electric vehicles could enable the British public to conveniently share their cars to help create a cleaner, more altruistic post-COVID world.</p><img src="https://counter.theconversation.com/content/143053/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andy Cruden receives funding from UKRI (both the Engineering and Physical Sciences Research Council and Innovate-UK) and from a range of industry partners related to the energy storage sector. </span></em></p>Grid-scale batteries could be at least double the cost of those in electric vehicles.Andrew Cruden, Professor of Energy Technology, University of SouthamptonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1136352019-05-29T12:34:16Z2019-05-29T12:34:16ZA radical idea to get a high-renewable electric grid: Build way more solar and wind than needed<figure><img src="https://images.theconversation.com/files/274683/original/file-20190515-60545-13v85bk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Expanding solar power potential more than it's needed could replace more expensive energy storage.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/103707855@N05/16674867575/in/faves-41182236@N00/">Jamey Stillings</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>The famous inventor Edwin Land <a href="https://www.brainyquote.com/quotes/edwin_land_199296">said</a>, “It’s not that we need new ideas, but we need to stop having old ideas.” He seemed to be telling us that solutions lie just beyond our old habits of thinking. </p>
<p>Cities, states and countries around the world are committing to clean energy economies that run on very high levels – even 100% – of renewable energy. In New York state alone, four competing bills target <a href="https://www.windpowerengineering.com/business-news-projects/new-york-lawmakers-propose-bill-in-support-of-existing-renewable-projects/">50% to 100% renewables</a> by or before 2040.</p>
<p>Realistically, only two renewable energy resources <a href="http://asrc.albany.edu/people/faculty/perez/2015/IEA.pdf">are large enough</a> to meet these very high-penetration objectives on the supply side in the U.S. – solar (by far) and wind. </p>
<p>Both, however, are variable resources, driven by weather as well as daily and seasonal cycles. Therefore, they must be “firmed” – that is, capable of delivery power on demand – in order to replace fossil resources which can be dispatched as needed. Based on our research, we contend that this firm power transformation is not only possible, it is also affordable – if we stop having old ideas.</p>
<p>One entrenched, and very prevalent, idea – likely a result of historically high renewable energy prices – is that all the power generated by renewable resources must be sold as it is generated. The idea of discarding available wind or solar output is anathema, imposed on power producers when production from these sources exceeds what the grid can accept. </p>
<p>This old idea ignores a fundamental proposition: <a href="https://doi.org/10.1016/j.solener.2018.12.074">oversizing and proactively curtailing wind and solar</a>. However counterintuitive, a study our colleagues and we conducted shows that these steps are the key to the least expensive path to an electric grid powered largely by solar and wind. </p>
<h2>Weighing against energy storage</h2>
<p>The reasoning behind overprovisioning solar and wind is straightforward:</p>
<ul>
<li><p><a href="https://theconversation.com/how-energy-storage-is-starting-to-rewire-the-electricity-industry-93259">Energy storage</a> is the one essential ingredient needed to fill renewable energy variability when the sun does not shine or the wind does not blow. These gaps include intra-day periods, such as hours of peak demand during the day and nights, and more importantly, larger multi-day and seasonal gaps from sustained low-sun or low-wind conditions. For storage, grid operators – the organizations that ensure power supply matches demand as it rises and falls during the day – typically rely on water reservoirs called <a href="https://www.energy.gov/eere/water/pumped-storage-hydropower">pumped hydro</a> or, for shorter periods, batteries. </p></li>
<li><p>Storage is getting cheaper, but even assuming the most optimistic long-term cost projections, our <a href="https://doi.org/10.1016/j.solener.2018.12.074">study</a> led us to conclude that applying storage alone to firm wind or solar will remain prohibitively expensive because of the size of multi-day and seasonal gaps. Wind and solar are becoming much less expensive as well, <a href="https://www.greentechmedia.com/articles/read/nevada-beat-arizona-record-low-solar-ppa-price#gs.afha0l">especially solar</a>, to the point where overbuilding is increasingly affordable. This is true even when the output from wind and solar generators is essentially dumped, or “curtailed,” and not fed into the grid.</p></li>
<li><p>Oversizing reduces production gaps because more energy output is available during periods of low solar and wind availability. Overbuilding also reduces storage requirements. </p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/276675/original/file-20190528-193527-1a58oj6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This chart shows how providing round-the-clock energy from wind and solar with storage only remains far more expensive than ‘grid parity,’ the cost of natural gas-supplied power (B). But storage combined with excess wind and solar that is curtailed about 30% of the time can be less expensive than grid parity and deliver power on demand (C).</span>
<span class="attribution"><span class="source">Richard Perez, Karl R. Rabago</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>‘Firming’ with overcapacity</h2>
<p>Today, the current regulatory practice for solar and wind-generated electricity favors maximizing production at all times. The companies that operate these facilities seek to sell all their output at the highest prices, so curtailing output is seen as a revenue loss.</p>
<p>That old operational idea inhibits the transition to relying on solar and wind as firm, on-demand sources, since all their output is used only when it is available. This approach also keeps renewable energy at the margin.</p>
<p>How would a grid with overbuilt solar and wind resources work in practice? Let’s say the operator of a regional electricity grid needs X megawatt-hours/day to meet demand. Today the solar farms in that region can meet or exceed this demand only on days of the highest production, such as clear days in the summer. On other days, the production gaps are met by storage. </p>
<p>By contrast, when the solar resource is oversized, that solar generator can meet the X MWh/day demand more days of the year and there are fewer gaps – hence there are fewer times that energy storage is need to fill the gaps.</p>
<p>Once firmed up through a combination of overprovisioning and storage, variable renewable energy resources become effectively dispatchable – able to provide power when as needed – and functionally equivalent to traditional power plants. In this way, renewables can replace these generators without major grid reengineering. </p>
<p>Our team has modeled a <a href="http://mnsolarpathways.org/wp-content/uploads/2018/11/solar-potential-analysis-final-report-nov15-2.pdf">high-solar and overbuilt solution</a> for the not particularly sunny state of Minnesota. The goal was to determine the least costly combination of grid-connected solar, wind and storage necessary to provide round-the-clock, year-round energy services. </p>
<p>The study demonstrates that overcoming the natural variability of solar and wind can be accomplished at costs below current grid costs (so-called “grid parity”) by overbuilding solar and wind resources and adopting a grid operating strategy of allowing about 20% to 40% curtailment of excess energy generation. Energy storage is also used in our model, but the superior economics directly result from substituting excess curtailable generation for more expensive storage. </p>
<p>A legitimate question to ask is what would be the area required for a full deployment of oversized solar PV. For Minnesota, in the most extreme 100% PV generation scenario assuming oversizing by a factor of two – or doubling the solar needed to meet current demand – this area would amount to 435 square miles, assuming solar panels with state-of-the-art efficiency of 20%. This area represents <a href="https://www.sciencedirect.com/science/article/pii/S0038092X18308582">less than 1% of the state’s</a> cultivated crops and half of the high- and medium-density urbanized space. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=472&fit=crop&dpr=1 600w, https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=472&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=472&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=594&fit=crop&dpr=1 754w, https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=594&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/275698/original/file-20190521-23838-4qonme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=594&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Grid operators can benefit by managing wind and solar on a regional basis, because their periods of high output can complement each other. Winter wind, for instance, is often strongest at night, while solar output is highest in summer months.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/iip-photo-archive/16528848257/in/photolist-rbAEJn-dyoEFA-r7H2Nr-8nnv7V-PXksk8-5u8bbz-2bhTqem-8gLyR8-28bqXoH-oD3UH8-jwMES-2fv79UH-aJxxEZ-9FUKfq-95qZ1V-95u3sj-4mVjkn-4mZk8q-4mVcFT-95u4eC-4mVkUP-4mZ7Wd-dMNZ4V-aJxjU6-aVfMvx-5Fs13C-aJwFVZ-9FUEcQ-9GJBdU-avs1j1-aNGd8v-9rNmqE-6jXYcS-7b3sfu-RNnkbP-aJwr5T-7vTL6V-6jBcih-6jxKBi-aNGvh8-9FUvbf-5Tscj8-6jxKTi-6fNEBM-7b3rGL-RGxMCJ-7HA5R3-7vYJAf-aJwGuF-7b3qYW">IIP Photo Archive</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<h2>Tweaking how the bulk power grid is run</h2>
<p>In addition to oversizing, curtailment and storage optimization, several operational and planning practices, some of which are already done now, would further enhance the value and performance of a high-solar grid and foster its realization with minimal disruptions. They include:</p>
<ul>
<li><p>Exploiting the complementary performance and variable operating profiles of solar and wind. In most locations wind and solar have complementary diurnal and seasonal production profiles – wind higher at night and in winter, PV higher in the daytime in summer. </p></li>
<li><p>Utilizing demand management – the practice of reducing power use at electricity customer locations – as a way to minimize supply and demand gaps. </p></li>
<li><p>Enabling grid operators to have authority over renewable energy siting and production management within their regions so that decisions over when curtailment occurs or storage is applied are made on a regional basis to minimize gaps in supply and demand. </p></li>
</ul>
<p>An attitude of maximizing renewable energy production and avoiding curtailment made sense when variable solar generation was extremely expensive and firming solutions were even more expensive. However, recent and forecast reductions in turnkey solar, grid management and storage costs are changing the optimal solution set, starting with overbuilding solar. </p>
<p><em>Marc Perez, senior researcher at Clean Power Researcher, who wrote his dissertation at Columbia University on this subject, contributed to this article. Morgan Putnam, VP of Solar Analytics at REsurety, also contributed.</em></p><img src="https://counter.theconversation.com/content/113635/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Perez works at the University at Albany. He has received research funding from the USDOE, Environment Canada, NASA, NYSERDA and Clean Power Research.
He is a member of the American and International Solar Energy Societies.
Clean Power Research led the USDOE-funded Minnesota Solar Pathways project that demonstrated the firm power generation optimization results presented herein. The project’s Lead Scientist was Marc Perez, and project PI was Morgan Putnam. The authors also acknowledge the USDOE-funded Northeast Solar Energy Market Coalition (NSEMC) project to harmonize solar policies in the northeastern US.</span></em></p><p class="fine-print"><em><span>Karl R. Rábago works for the Pace Energy and Climate Center, a not-for-profit project of Pace University. He is also principle of Rábago Energy LLC, a consulting business. The Pace Energy and Climate Center currently receives and has received a wide variety of private foundation grants, federal funding, state funding. Rábago is also a member of the Board of Directors of the Center for Resource Solutions, ACE-NY, and Solar United Neighbors. </span></em></p>Solar and wind can’t deliver power on demand. But overbuilding solar and wind, and simply dumping unneeded energy, would go a long way to smoothing out those bumps, study finds.Richard Perez, Senior Research Associate in Atmospheric Sciences Research Center, University at Albany, State University of New YorkKarl R. Rabago, Professor of Law; Executive Director, Pace Energy and Climate Center, Pace University Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1126102019-03-06T19:12:40Z2019-03-06T19:12:40ZFive gifs that explain how pumped hydro actually works<p>People have used moving water to create energy for thousands of years. Today, pumped hydro is the most common form of grid-connected energy storage <a href="https://www.energystorageexchange.org">in the world</a>.</p>
<p>This technology is in the spotlight because it pairs so well with solar and wind renewable energy. During the day, when solar panels and wind farms may be generating their highest level of energy, people don’t need really need much electricity. Unless it is stored somewhere the energy is lost.</p>
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Read more:
<a href="https://theconversation.com/snowy-hydro-scheme-will-be-left-high-and-dry-unless-we-look-after-the-mountains-74830">Snowy hydro scheme will be left high and dry unless we look after the mountains</a>
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<p>Pumped hydro can cheaply and easily store the excess energy, releasing it again at night when demand rises.</p>
<p>Here’s how it all works:</p>
<h2>How it works</h2>
<p>Put as simply as possible, it involves pumping water to a reservoir at the top of a hill when energy is in plentiful supply, then letting it flow back down through a turbine to generate electricity when demand increases.</p>
<p><img src="https://cdn.theconversation.com/static_files/files/507/Sc01.gif" width="100%"></p>
<p>Like all storage systems, you get less energy <em>out</em> than you put <em>in</em> – in this case, generally around <a href="http://energystorage.org/energy-storage/technologies/pumped-hydroelectric-storage">80% of the original input</a> – because you lose energy to friction in the pipes and turbine as well as in the generator. For comparison, lithium ion batteries are around <a href="https://researchinterfaces.com/lithium-ion-batteries-grid-energy-storage/">90-95% efficient</a>, while hydrogen energy storage is less than <a href="http://energystorage.org/energy-storage/technologies/hydrogen-energy-storage">50% efficient</a></p>
<p><img src="https://cdn.theconversation.com/static_files/files/508/Sc02.gif" width="100%"></p>
<p>The benefit is we can store a lot of energy at the top of the hill and keep it there in a reservoir until we need the energy back again. Then it can be released through the pipes (this is called “penstock”) to generate electricity. This means pumped hydro can create a lot of additional electricity when demand is high (for example, during a heatwave). </p>
<p>The disadvantage of pumped hydro is you need to have two reservoirs separated by a significant elevation difference (more than 200m is typically required, more than 300m is ideal). So it doesn’t work where you don’t have hills. However, research has identified <a href="https://theconversation.com/want-energy-storage-here-are-22-000-sites-for-pumped-hydro-across-australia-84275">22,000 potential sites</a> in Australia. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/want-energy-storage-here-are-22-000-sites-for-pumped-hydro-across-australia-84275">Want energy storage? Here are 22,000 sites for pumped hydro across Australia</a>
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<p><img src="https://cdn.theconversation.com/static_files/files/513/Sc03.gif" width="100%"></p>
<p>Pumped hydro is traditionally paired with relatively inflexible coal or nuclear power stations, using under-utilised electricity when demand is low (weekends and nighttime), then providing additional generation when demand increases during the day and into the evening. </p>
<p>With the rapid increase in deployment of wind and solar, pumped hydro is again gaining interest. This is because the output of wind and solar plant is subject to the variability in the weather. For example, solar power plants generate the most electricity in the middle of the day, while demand for electricity is often highest in the evening. The wind might die down for hours or even days, then suddenly blow a gale. Pumped hydro can play a key role in smoothing out this variability.</p>
<p><img src="https://cdn.theconversation.com/static_files/files/516/Sc04.gif" width="100%"></p>
<p>If the electricity being produced by wind and solar plant is greater than demand, then the energy has to be curtailed (and is lost), unless we have a way to store it. Using this excess power to pump water up hill means the solar or wind energy is not wasted and the water can be held in reservoirs until demand rises in the evening.</p>
<p><img src="https://cdn.theconversation.com/static_files/files/518/Sc05.gif" width="100%"></p>
<p>There are lots of different kinds of energy storage technologies, each with their own advantages and disadvantages. For large-scale grid-connected systems where many hours of storage are required, pumped hydro is the <a href="https://www.lazard.com/media/438042/lazard-levelized-cost-of-storage-v20.pdf">most economically viable</a> option.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/snowy-hydro-gets-a-boost-but-seawater-hydro-could-help-south-australia-74442">Snowy Hydro gets a boost, but 'seawater hydro' could help South Australia</a>
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<img src="https://counter.theconversation.com/content/112610/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roger Dargaville has received funding from the Australian Renewable Energy Agency (ARENA) for energy system modelling projects. He works as a consultant with Energy Australia on pumped hydro projects, including the Cultana seawater pumped hydro project in South Australia.</span></em></p>Everything you need to know about pumped hydro.Roger Dargaville, Senior lecturer, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1109612019-02-22T11:42:24Z2019-02-22T11:42:24ZUtilities are starting to invest in big batteries instead of building new power plants<figure><img src="https://images.theconversation.com/files/259141/original/file-20190214-1758-1hkveub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This is what a 5-megawatt, lithium-ion energy storage system looks like.</span> <span class="attribution"><a class="source" href="https://www.pnnl.gov/news/release.aspx?id=990">Pacific Northwest National Laboratory</a></span></figcaption></figure><p>Due to their decreasing costs, <a href="https://batteryuniversity.com/learn/archive/is_lithium_ion_the_ideal_battery">lithium-ion batteries</a> now dominate a range of applications including electric vehicles, computers and consumer electronics.</p>
<p>You might only think about energy storage when your laptop or cellphone are running out of juice, but utilities can plug bigger versions into the electric grid. And thanks to rapidly declining <a href="https://www.lazard.com/perspective/levelized-cost-of-energy-and-levelized-cost-of-storage-2018/">lithium-ion battery prices</a>, using <a href="https://theconversation.com/how-energy-storage-is-starting-to-rewire-the-electricity-industry-93259">energy storage</a> to stretch electricity generation capacity. </p>
<p>Based on <a href="https://scholar.google.com/citations?user=a1U0FOYAAAAJ&hl=en">our research</a> on <a href="https://scholar.google.com/citations?user=ILteTxGUH0AC&hl=en">energy storage costs and performance</a> in North Carolina, and <a href="http://go.ncsu.edu/energy_storage">our analysis</a> of the potential role energy storage could play within the coming years, we believe that utilities should prepare for the advent of cheap grid-scale batteries and develop flexible, long-term plans that will save consumers money.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=299&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=299&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=299&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=376&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=376&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259345/original/file-20190215-56204-iv2o29.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=376&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">All of the new utility-scale electricity capacity coming online in the U.S. in 2019 will be generated through natural gas, wind and solar power as coal, nuclear and some gas plants close.</span>
<span class="attribution"><a class="source" href="https://www.eia.gov/todayinenergy/detail.php?id=37952">U.S. Energy Information Administration</a></span>
</figcaption>
</figure>
<h2>Peak demand is pricey</h2>
<p>The amount of electricity consumers use varies according to the time of day and between weekdays and weekends, as well as seasonally and annually as everyone goes about their business. </p>
<p>Those variations can be huge.</p>
<p>For example, the times when consumers use the most electricity in many regions is <a href="https://www.eia.gov/todayinenergy/detail.php?id=15051">nearly double the average</a> amount of power they typically consume. Utilities often meet peak demand by building power plants that run on natural gas, due to their <a href="https://openei.org/apps/TCDB/transparent_cost_database#blank">lower construction costs</a> and ability to operate when they are needed.</p>
<p>However, it’s expensive and inefficient to build these power plants just to meet demand in those peak hours. It’s like purchasing a large van that you will only use for the three days a year when your brother and his three kids visit. </p>
<p>The grid requires power supplied right when it is needed, and usage varies considerably throughout the day. When <a href="https://theconversation.com/how-energy-storage-is-starting-to-rewire-the-electricity-industry-93259">grid-connected batteries</a> help supply enough electricity to meet demand, utilities don’t have to build as many power plants and transmission lines.</p>
<p>Given how long this infrastructure lasts and how rapidly battery costs are dropping, utilities now face new long-term planning challenges.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=468&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=468&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259095/original/file-20190214-1745-1fy1ojh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=468&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Grid-scale batteries are being installed coast-to-coast as this snapshot from 2017 indicates. Source: U.S. Energy Information Administration, U.S. Battery Storage Market Trends, 2018.</span>
</figcaption>
</figure>
<h2>Cheaper batteries</h2>
<p><a href="https://electrek.co/2018/01/12/94-percent-new-electricity-capacity-usa-from-renewables/">About half</a> of the new generation capacity built in the U.S. annually since 2014 has come from solar, wind or other <a href="https://www.eia.gov/todayinenergy/detail.php?id=37952">renewable sources</a>. Natural gas plants make up the much of the rest but in the future, that industry may need to compete with energy storage for <a href="https://www.eia.gov/tools/faqs/faq.php?id=427&t=3">market share</a>.</p>
<p>In practice, we can see how the pace of <a href="https://www.greentechmedia.com/articles/read/6-charts-showing-the-renewables-threat-to-gas#gs.HiVuwxsu">natural gas-fired</a> power plant construction might slow down <a href="https://www.greentechmedia.com/articles/read/garcetti-la-5-billion-rebuild-coastal-gas-plants#gs.dOBX0UQP">in response</a> to this new alternative. </p>
<p>So far, utilities have only installed the <a href="https://www.eia.gov/analysis/studies/electricity/batterystorage/">equivalent of one or two traditional power plants</a> in grid-scale lithium-ion battery projects, all since 2015. But across <a href="https://www.eia.gov/analysis/studies/electricity/batterystorage/">California, Texas, the Midwest and New England</a>, these devices are benefiting the overall grid by improving operations and bridging gaps when consumers need more power than usual. </p>
<p><iframe id="ctGM9" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/ctGM9/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Based on our own experience tracking lithium-ion battery costs, we see the potential for these batteries to be deployed at a far larger scale and disrupt the energy business.</p>
<p>When we were given approximately one year to conduct a study on the <a href="http://go.ncsu.edu/energy_storage">benefits and costs of energy storage in North Carolina</a>, keeping up with the pace of technological advances and increasing affordability was a struggle.</p>
<p>Projected battery costs changed so significantly from the beginning to the end of our project that we found ourselves rushing at the end to update our analysis.</p>
<p>Once utilities can easily take advantage of these huge batteries, they will not need as much new power-generation capacity to meet peak demand.</p>
<p><iframe id="RdJ7C" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/RdJ7C/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<h2>Utility planning</h2>
<p>Even before batteries could be used for large-scale energy storage, it was hard for utilities to make long-term plans due to uncertainty about what to expect in the future.</p>
<p>For example, most energy experts did not anticipate the dramatic decline in <a href="https://www.eia.gov/dnav/ng/hist/rngwhhdW.htm">natural gas prices</a> due to the spread of hydraulic fracturing, or fracking, starting about a decade ago – or the incentive that it would provide utilities to <a href="https://phys.org/news/2018-05-natural-gas-prices-war-coal.html">phase out coal-fired power plants</a>.</p>
<p>In recent years, <a href="https://www.energy.gov/articles/energy-department-announces-achievement-sunshot-goal-new-focus-solar-energy-office">solar energy</a> and <a href="https://emp.lbl.gov/wind-technologies-market-report">wind power</a> costs have dropped far faster than expected, also displacing coal – and in some cases natural gas – as a source of <a href="https://www.vox.com/energy-and-environment/2018/7/13/17551878/natural-gas-markets-renewable-energy">energy for electricity generation</a>. </p>
<p>Something we learned during our storage study is illustrative.</p>
<p>We found that lithium ion batteries at 2019 prices were a bit too expensive in North Carolina to compete with natural gas <a href="https://www.clarke-energy.com/natural-gas/peaking-station-peak-lopping-plants/">peaker plants</a> – the natural gas plants used occasionally when electricity demand spikes. However, when we modeled projected 2030 battery prices, energy storage proved to be the more <a href="https://www.ge.com/power/transform/article.transform.articles.2018.oct.storage-threat-to-peaker-plants">cost-effective option</a>. </p>
<p>Federal, state <a href="https://www.lamayor.org/mayor-garcetti-ladwp-will-phase-out-natural-gas-operations-three-power-plants">and even some local</a> policies are another wild card. For example, Democratic lawmakers have outlined the <a href="https://www.vox.com/energy-and-environment/2019/2/7/18211709/green-new-deal-resolution-alexandria-ocasio-cortez-markey">Green New Deal</a>, an ambitious plan that could rapidly address climate change and income inequality at the same time.</p>
<p>And no matter what happens in Congress, the <a href="https://nca2018.globalchange.gov/">increasingly frequent</a> bouts of <a href="https://www.utilitydive.com/news/polar-vortex-set-to-test-midwest-grids-amid-ferc-resilience-debate/547231/">extreme weather</a> hitting the U.S. are also expensive for utilities. <a href="https://www.eia.gov/todayinenergy/detail.php?id=18271">Droughts reduce hydropower</a> output and <a href="https://www.powermag.com/intense-summer-heatwaves-rattle-worlds-power-plants/?pagenum=1">heatwaves make electricity usage spike</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259392/original/file-20190217-56246-cjo28x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Scattergood power plant in Los Angeles is one of three natural gas power plants slated to shut down by 2029.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Power-Plants-Los-Angeles/854bad6a63634491bb61f835c593b255/2/0">AP Photo/Marcio Jose Sanchez</a></span>
</figcaption>
</figure>
<h2>The future</h2>
<p>Several utilities are already investing in energy storage.</p>
<p>California utility <a href="https://www.greentechmedia.com/articles/read/pges-recording-breaking-battery-proposal-wins-loses#gs.Sr3iJwMw">Pacific Gas & Electric</a>, for example, got permission from regulators to build a massive 567.5 megawatt energy-storage battery system near San Francisco, although the <a href="https://www.utilitydive.com/news/pge-to-file-for-bankruptcy-protection-as-california-wildfire-costs-mount/545974/">utility’s bankruptcy</a> could complicate the project.</p>
<p>Hawaiian Electric Company <a href="https://www.greentechmedia.com/articles/read/hawaiian-electric-industries-announces-mind-blowing-solar-plus-storage-cont#gs.d6b2toPJ">is seeking approval</a> for projects that would establish several hundred megawatts of energy storage across the islands. And <a href="https://www.utilitydive.com/news/taming-the-duck-arizona-public-service-seeks-106-mw-storage-for-solar-plan/527088/">Arizona Public Service</a> and <a href="https://www.greentechmedia.com/articles/read/final-irp-proposal-for-puerto-rico-calls-for-mini-grids-and-rapid-solar-and#gs.yX3tmTbf">Puerto Rico Electric Power Authority</a> are looking into storage options as well.</p>
<p>We believe these and other decisions will reverberate for decades to come.
If utilities miscalculate and spend billions on power plants it turns out they won’t need instead of investing in energy storage, their customers could pay more than they should to keep the lights through the middle of this century.</p><img src="https://counter.theconversation.com/content/110961/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeremiah Johnson receives funding from the U.S. National Science Foundation, the U.S. Department of Energy, and the NC Policy Collaboratory. </span></em></p><p class="fine-print"><em><span>Joseph F. DeCarolis receives funding from the National Science Foundation and the NC Policy Collaboratory to conduct related research on energy systems.</span></em></p>Energy storage could prove an inexpensive way for power companies to handle heat waves and other times when consumers use more electricity than usual.Jeremiah Johnson, Associate Professor of Environmental Engineering, North Carolina State UniversityJoseph F. DeCarolis, Associate Professor of Environmental Engineering, North Carolina State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/932592018-03-22T10:42:29Z2018-03-22T10:42:29ZHow energy storage is starting to rewire the electricity industry<figure><img src="https://images.theconversation.com/files/211315/original/file-20180321-165568-1fs0fme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Grid-scale energy storage systems may make it easier to rely completely on renewable energy.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/concept-energy-storage-system-renewable-photovoltaics-764275429?src=a66vvy9sQqP4S80I_RmvEw-1-9">petrmalinak/Shutterstock.com</a></span></figcaption></figure><p>The market for <a href="https://www.ucsusa.org/clean-energy/how-energy-storage-works#.WrI4ZejwZPY">energy storage</a> on the power grid is growing at a rapid clip, driven by <a href="https://www.greentechmedia.com/research/report/us-front-of-the-meter-energy-storage-system-prices-2018-2022#gs.R9NuWs8">declining prices</a> and supportive government policies.</p>
<p>Based on our research on <a href="https://scholar.google.com/citations?user=JK5UuEYAAAAJ&hl=en">the operation and costs of electricity grids</a>, especially the <a href="https://scholar.google.com/citations?hl=en&user=A9RAOJEAAAAJ">benefits of new technologies</a>, we are confident energy storage could transform the way American homeowners, businesses and utilities produce and use power.</p>
<h2>Balancing acts</h2>
<p>Energy storage in this context simply means saving electricity for later use. It’s like having a bunch of rechargeable batteries, but much larger than the ones in your cellphone and probably connected to the grid. </p>
<p>After <a href="https://www.greentechmedia.com/articles/read/us-energy-storage-deployments-up-46-percent-annually-in-q3-2017#gs.gbasP9w">annual average growth of about 50 percent</a> for five years, the U.S. electricity industry installed a total of <a href="http://energystorage.org/news/esa-news/us-energy-storage-market-tops-gwh-milestone-2017-annual-deployments-exceed-1000-mwh">1 gigawatt-hour of new storage capacity</a> between 2013 and 2017, according to the firm GTM Research. That’s enough to power 16 million laptops for several hours. While this amount of storage is less than 0.2 percent of the <a href="https://www.eia.gov/todayinenergy/detail.php?id=9671">average amount of electricity the U.S. consumes</a>, analysts predict that installations will double between 2017 and 2018 and then <a href="https://about.bnef.com/blog/global-storage-market-double-six-times-2030/">keep expanding rapidly</a> in the U.S. and around the world. </p>
<p>To see why this trend is a big deal, consider how electricity works.</p>
<p>It takes a hidden world of complexity and a series of delicate balancing acts to power homes and workplaces because the grid has historically had little storage capacity. After being generated at power plants, electricity usually travels down power lines at the speed of light and most of it is consumed immediately.</p>
<p>Without the means to store electricity, utilities have to produce just enough to meet demand around the clock, including peak hours.</p>
<p>That makes electricity different from most industries. Just imagine what would happen if automakers had to do this. The moment you bought a car, a worker would have to drive it out the factory gate. Assembly lines would constantly speed up and slow down based on consumer whims.</p>
<p>It sounds maddening and ridiculous, right? But <a href="https://www.eia.gov/todayinenergy/detail.php?id=27192">electric grid operators</a> basically pull this off, balancing supply and demand every few seconds by turning power plants on and off. </p>
<p>That’s why a storage boom would make a big difference. Storage creates the equivalent of a warehouse to stow electricity when it is plentiful for other times when it is needed.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/P_d0x8uG6kE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The U.S. Energy Department’s SunShot Initiative aims to reduce the cost of solar energy and to make it easier to deploy.</span></figcaption>
</figure>
<h2>Stretching power</h2>
<p>Energy storage can help in a variety of ways, essentially serving as a Swiss Army knife for electricity grids. It can help balance short-term power fluctuations, manage peak demand or act as a backup to prevent or recover from power outages.</p>
<p>And it can be deployed at <a href="https://www.eia.gov/todayinenergy/detail.php?id=4310">any scale and at any point in the grid</a>, from a <a href="https://www.greentechmedia.com/articles/read/us-residential-grid-tied-energy-storage-is-overtaking-off-grid-storage#gs.743z41g">small home storage system</a> to a <a href="https://www.eia.gov/todayinenergy/detail.php?id=11991">pumped hydroelectric</a> reservoir big enough to power a small city. While storage <a href="https://theconversation.com/does-energy-storage-make-the-electric-grid-cleaner-90001">actually consumes a little electricity rather than producing any</a>, it makes the electricity business more economically efficient. As the volume of storage grows, we expect grids to become more stable and flexible. </p>
<p>Storage may also make a big difference with electricity generated through solar or wind power – which can only be harnessed when the sun is shining and the wind is blowing. </p>
<p>But, in general, it isn’t necessary for that purpose yet. While those industries are growing quickly, <a href="https://www.eia.gov/tools/faqs/faq.php?id=427&t=3">wind power generates only about 6 percent of U.S. electricity and solar less than 2 percent</a>. Electricity grids can currently use almost all of that power as it is produced.</p>
<p>Grid operators, accustomed to managing the variable supply and demand for power, <a href="https://www.greentechmedia.com/articles/read/for-u-s-grid-markets-an-eclipse-day-is-like-any-other-day#gs.u3WmQtc">can manage the extra unpredictability</a> they get from wind and solar energy now. But as utilities, businesses and consumers bring more renewable energy online, the grid may become harder to balance without additional storage.</p>
<p>To be sure, <a href="http://www.wvic.com/content/how_hydropower_works.cfm">hydroelectric plant operators</a> have been storing power for a long time. The U.S. has the capacity to store <a href="https://www.eia.gov/todayinenergy/detail.php?id=11991">some 22 gigawatts</a> in pumped hydropower, about 2 percent of U.S. generating capacity. Yet its reliance on large water reservoirs, which can’t be easily constructed near power markets, limits the growth potential of this energy option. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211428/original/file-20180321-165571-16sgxsj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Seneca pumped storage reservoir, on the left, and the Kinzua Dam on the Allegheny River in Warren County near Warren, Pa.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:USACE_Kinzua_Dam_downriver.jpg">U.S. Army Corps of Engineers Digital Visual Library</a></span>
</figcaption>
</figure>
<h2>Competing with natural gas</h2>
<p>Once energy storage scales up, utilities will meet peak demand more easily with less total capacity and fewer power plants. If they can rely on storage to supply power during high-demand hours instead of building new power plants, it can save money all around.</p>
<p>But storage isn’t the only game in town – other technologies offer similar benefits. Utilities can install new transmission lines or rely on flexible natural gas, which is essentially the <a href="https://www.greentechmedia.com/events/webinar/will-energy-storage-replace-peaker-plants#gs.IrSw3kg">biggest competitor for energy storage</a>.</p>
<p>Natural gas generation produces about a third of the nation’s electricity today and provides many of the same benefits as storage since these power plants are easy to switch on and off. The relatively low prices for <a href="https://www.eia.gov/dnav/ng/hist/rngwhhdm.htm">natural gas</a>, less than half of what they were a decade ago due to widespread hydrofracking, <a href="https://www.washingtonpost.com/news/energy-environment/wp/2015/10/02/the-surprising-factor-thats-holding-back-the-energy-storage-revolution/">have probably slowed energy storage</a> growth until now. </p>
<p>Natural gas has become <a href="https://www.eia.gov/todayinenergy/detail.php?id=35412">increasingly popular</a> for power generation, <a href="https://www.eia.gov/todayinenergy/detail.php?id=33992">displacing demand for coal</a> <a href="https://www.eia.gov/todayinenergy/detail.php?id=34172">since 2000</a>. But if storage gets cheap enough, this equation may flip and storage could threaten the economics of <a href="https://www.eia.gov/outlooks/steo/report/natgas.php">natural gas generation</a>.</p>
<h2>Help from the government and better batteries</h2>
<p>One reason why this industry is growing is that it’s getting a boost from the government.</p>
<p><a href="https://www.utilitydive.com/news/maryland-hawaii-turn-to-storage-incentives-as-state-markets-gain-momentum/444261/">California, Maryland, New Jersey and Nevada</a> are subsidizing storage, mandating its adoption or both. A similar measure is pending in <a href="https://pv-magazine-usa.com/2018/01/18/hawaii-legislature-considers-income-tax-credit-for-energy-storage/">Hawaii’s legislature</a>.</p>
<p>And despite the Trump administration’s efforts to maximize <a href="https://www.politico.com/story/2017/10/10/trump-obama-climate-clean-energy-243655">fossil fuel extraction</a>, the federal government is now laying the regulatory groundwork for the storage industry to <a href="https://www.utilitydive.com/news/ferc-order-opens-floodgates-for-energy-storage-in-wholesale-markets/517326/">compete directly in open wholesale energy markets</a> for the first time. </p>
<p>Improvements in technology have made a difference, too. Battery technology, led by the same <a href="https://electronics.howstuffworks.com/everyday-tech/lithium-ion-battery.htm">lithium-ion</a> design that powers mobile phones, is making big strides and getting much cheaper. </p>
<p>Lithium-ion batteries are both responsible for most of this new wave of grid-connected energy storage and the critical component inside the rapidly growing number of American <a href="https://arstechnica.com/cars/2018/01/2017-was-the-best-year-ever-for-electric-vehicle-sales-in-the-us/">electric vehicles</a>. For example, the lithium-ion battery used in the the <a href="https://www.energysage.com/solar/solar-energy-storage/tesla-powerwall-home-battery/">Tesla Powerwall</a>, a home battery system, is the same as the one the company uses in its vehicles.</p>
<p>Grid-scale lithium batteries often differ from those in cars but use the same basic technology. The price of utility-scale <a href="https://www.nature.com/articles/nenergy2017110">lithium-ion battery systems fell 40 percent in just five years</a> to around US$1,200 per kilowatt-hour in 2015 from roughly $2,100 in 2010 and are expected to <a href="https://www.greentechmedia.com/research/report/us-front-of-the-meter-energy-storage-system-prices-2018-2022#gs.6zXdSM4">continue falling</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211321/original/file-20180321-165574-gqd03g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rhonda ‘Honey’ Phillips, alongside the Tesla Powerwall battery and inverter connected to solar panels in her Middletown Springs, Vt., yard.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Storing-Solar-Energy/cd855dfd18a54e3b9a1cb7a346d8cf5b/1/0">AP Photo/Dave Gram</a></span>
</figcaption>
</figure>
<h2>The future</h2>
<p>The grid currently has relatively little storage for the same reason that only about <a href="https://arstechnica.com/cars/2018/01/2017-was-the-best-year-ever-for-electric-vehicle-sales-in-the-us/">200,000</a> of the <a href="https://www.usatoday.com/story/money/cars/2018/01/03/u-s-auto-sales-record-streak-likely-snapped-2017/999182001/">17.2 million vehicles</a> Americans bought in 2017 were electric: It’s expensive today. </p>
<p>Electric vehicles do not yet save money for most U.S. drivers. But market experts project that <a href="https://about.bnef.com/blog/the-electric-car-revolution-is-accelerating/">electric vehicles</a> ownership will cost less than standard vehicles powered by gasoline within a decade and continue getting cheaper after that.</p>
<p>Likewise, for the electricity grid, if storage gets cheap enough, its potential market could expand from 1 gigawatt-hour to dozens or even <a href="https://about.bnef.com/blog/global-storage-market-double-six-times-2030/">hundreds of gigawatt-hours</a>. </p>
<p>If or when that happens, wind and solar power would become more competitive, increasingly displacing both coal and natural gas – now the nation’s <a href="https://www.eia.gov/tools/faqs/faq.php?id=427&t=3">two top sources of electric power</a>. And this cheaper storage would also make <a href="https://about.bnef.com/electric-vehicle-outlook/">electric vehicles more affordable</a>, reducing the amount of <a href="https://www.eia.gov/tools/faqs/faq.php?id=33&t=6">gasoline and diesel</a> Americans consume. The electricity and automotive industries operate nearly the same way they did 50 years ago. But a world of low-cost batteries would change them both in exciting and unprecedented ways.</p>
<p>No matter what happens, we believe that storage is “future-proof” because it works well on the current grid and with a wide variety of other technologies. If the wind and solar industries keep up their current momentum (<a href="https://about.bnef.com/blog/global-wind-solar-costs-fall-even-faster-coal-fades-even-china-india/">and they probably will</a>), storage will become even more valuable. But if the grid goes another direction – relying more on large and expensive generation plants, for example – storage would make it easier to manage peak demand without surplus capacity. Even if we can’t say exactly what the grid of the future will look like, we are pretty confident that storage will keep it humming in new ways.</p><img src="https://counter.theconversation.com/content/93259/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eric Hittinger receives funding from the National Science Foundation and occasionally provides consulting services for energy storage companies or developers. He is affiliated with the United States Association for Energy Economics. </span></em></p><p class="fine-print"><em><span>Eric Williams receives funding from the U.S. National Science Foundation.</span></em></p>Saving power to use later lets consumers, businesses and utilities generate energy when it’s cheap and deliver it when they need it most. There’s not much of it today, but the industry is growing fast.Eric Hittinger, Assistant Professor of Public Policy, Rochester Institute of TechnologyEric Williams, Associate Professor of Sustainability, Rochester Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/900012018-02-02T11:29:26Z2018-02-02T11:29:26ZDoes energy storage make the electric grid cleaner?<figure><img src="https://images.theconversation.com/files/204470/original/file-20180201-123826-1c5p2or.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Solar and wind compete with coal power plants when it comes to energy storage systems. </span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Outtakes-AP-F-A-NJ-USA-OTKME102-Wind-Power/4825e387fe704958b627298dbfa96950/1/0">AP Photo/Mel Evans</a></span></figcaption></figure><p>Carbon-free energy: Is the answer blowing in the wind? Perhaps, but the wind doesn’t always blow, nor does the sun always shine. The energy generated by wind and solar power is intermittent, meaning that the generated electricity goes up and down according to the weather. </p>
<p>But the output from the electricity grid must be controllable to match the second-by-second changing demand from consumers. So the intermittency of wind and solar power is an operational challenge for the electricity system. </p>
<p>Energy storage is a widely acknowledged solution to the problem of intermittent renewables. The idea is that storage charges up when the wind is blowing, or the sun is shining, then discharges later when the energy is needed. Storage for the grid can be a <a href="https://theconversation.com/has-tesla-cracked-the-grid-energy-storage-problem-41131">chemical battery</a> like those we use in electronic devices, but it can also take the form of <a href="http://energystorage.org/energy-storage/technologies/pumped-hydroelectric-storage">pumping water up a hill</a> to a reservoir and generating electricity when letting it flow back down, or storing and discharging <a href="http://www.necec.org/files/compressedair.pdf">compressed air</a> in an underground cavern.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/204472/original/file-20180201-123840-1jgfx4p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The most widely used form of energy storage on the electric grid is pumping water uphill and then releasing it at peak hours to run a power turbine.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/vattenfall/6779452824/in/photolist-bk5t8E-DYWf3V-WoVeHw-93PBhn-7KxWXc-boJjwL-Gn3k53-7Zn1FA-bxZmo6-boJgKE-7KxXia-e3JpuL-bBDaSH-boJfPQ-7KBU6y-7KxX4F-boJg2Y-b6HhS-bBDbbx-bBDb18-7Y7v5V-vrcgHd">Vattenfall</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Motivated by a view that storage is a “green” technology, governments are increasingly promoting utility-scale and distributed energy storage. For example, in November 2017, New York Gov. Andrew Cuomo signed a bill mandating <a href="https://www.nysenate.gov/legislation/bills/2017/a6571/amendment/original">targets for storage adoption by 2030</a>. Other states with similar policies are Oregon, Massachusetts, California and Maryland. Companies like Tesla also have been branding storage systems as clean technologies. </p>
<p>But do large storage systems lower emissions in our current grids? In a <a href="https://link.springer.com/article/10.1007/s12667-017-0266-4">recent study</a>, we found this isn’t necessarily the case – a reflection of how complex the electricity system can be. </p>
<h2>The role of coal</h2>
<p>Because storage can enable renewables to meet changing demand, we often assume the technology is inherently green – that is, by adding storage and renewables to the grid, we reduce greenhouse gas emissions. It’s similar to noticing that computers can provide education and productivity benefits, and then assuming that everything a person does on a computer is educational or productive. For both energy storage and computers, it depends on how you use it.</p>
<p>In our analysis, we found that adding storage can, for some grids, increase carbon emissions. While counterintuitive at first glance, this result makes sense when one considers how electricity grids are operated. Broadly speaking, the entire U.S. grid is operated as a <a href="https://www.geni.org/globalenergy/library/national_energy_grid/united-states-of-america/americannationalelectricitygrid.shtml">set of regional sub-grids</a> that cover the U.S. like a patchwork quilt. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=382&fit=crop&dpr=1 600w, https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=382&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=382&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=480&fit=crop&dpr=1 754w, https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=480&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/204473/original/file-20180201-123837-1c4d91s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=480&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tesla CEO Elon Musk introduces the company’s battery for the electric grid in 2015.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Tesla-Battery-Power-For-Homes/3000044cb9744888bd29300eed8d7dad/2/0">AP Photo/Ringo H.W. Chiu</a></span>
</figcaption>
</figure>
<p>Energy storage has no smokestack emissions like coal or natural gas power plants. But new storage affects the operation of other power plants on the grid, resulting in an increase or a decrease in carbon emissions depending on the type of power plants supplying electricity for that region. </p>
<p>In most cases, storage systems in the U.S. operate to maximize profit. To do this, storage “buys low and sells high.” Electricity is typically cheap at night when demand is low, and more expensive in the daytime, especially when people are getting home from work and turning on a bunch of appliances. So storage system operators tend to buy at night and sell during the day. The net effect of storage on emissions thus depends on what kind of generators are used to meet new demand at night versus the day. </p>
<p>In grids with a lot of coal power – Midwestern, Western and Southern states <a href="https://news.nationalgeographic.com/energy/2015/08/080115-seven-most-coal-dependent-states/">rely heavily on coal</a> – the coal plants are typically used to meet small changes in demand at night. Natural gas plants tend to work during the day to meet peak demand. In these electricity grids, storage tends to charge up with coal power at night, displacing natural gas power during the day. </p>
<p>Coal power is a dirtier source of electricity than natural gas, with about twice the carbon emissions for every unit of electricity produced. Therefore, in places where new storage means more coal and less natural gas generation, storage will increase total carbon emissions from the grid. </p>
<p>In the Midwest, we found that adding a storage capacity of 3 gigawatts, enough power to supply roughly 500,000 U.S. homes, raises carbon emissions an equivalent of adding 6,700 cars per year to the road. And as more storage is added, the carbon emissions increase. </p>
<p>On the other hand, we found that in New York, a state with very little coal power, adding storage reduces carbon emissions. The Midwest is currently the dirtiest electricity grid in the U.S., and New York is one of the cleanest, so other regions would fall somewhere in between.</p>
<h2>Not always easy being green</h2>
<p>So, how can grid planners achieve the promise of a happy marriage between storage and renewables, assuming that they have to live in the same house with crusty old Uncle Coal? </p>
<p>One possibility is that, even with storage operating to maximize profit, adding enough wind and solar to the grid could counteract the effect of coal. With enough excess renewable energy, storage in any form – batteries or water reservoirs, for example – would preferentially use solar and wind because they are the cheapest sources when the supply of power exceeds the demand. Storage would still be shifting coal power from night to day, but enabling renewables more would be enough to make up for the extra emissions. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=297&fit=crop&dpr=1 600w, https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=297&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=297&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=373&fit=crop&dpr=1 754w, https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=373&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/204474/original/file-20180201-123837-o9p3dc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=373&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Regulations can be designed so that energy storage systems charge up with excess electricity from wind and solar, which is a step toward making storage cleaner.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/concept-energy-storage-system-renewable-power-764274979?src=v11dtKH607ZWRsuerdjSEQ-1-11">petrmalinak/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>We studied this and found that for the Midwest grid there is a turning point when wind and solar reach about 18 percent of total generating capacity: At that point, adding storage starts to decrease rather than increase emissions. The current adoption level is 10 percent, so it would take some time before storage in the Midwest reduces emissions.</p>
<p>Another option is to change how storage is operated. With a modest price on carbon, for example, the cost of different generators would shift so that storage charges less often from coal plants, reducing emissions even in the coal-heavy Midwest grid. </p>
<p>While a national carbon tax does not look likely in the near future, there are others paths to ensuring green outcomes from storage. For example, states can put in place policies that encourage more use of zero-carbon resources instead of coal.</p>
<p>Regardless, storage will always help us to use more of our low-cost electricity sources. The question is whether that is coal, nuclear or renewables.</p><img src="https://counter.theconversation.com/content/90001/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Naga Srujana Goteti receives funding from the US National Science Foundation. </span></em></p><p class="fine-print"><em><span>Eric Hittinger receives funding from the National Science Foundation. </span></em></p><p class="fine-print"><em><span>Eric Williams receives funding from the U.S. National Science Foundation. </span></em></p>Energy storage, such as big batteries, on the power grid is generally seen as ‘green’ technology but the reality is more complicated, an analysis finds.Naga Srujana Goteti, PhD Student in Energy and Sustainabiltiy, Rochester Institute of TechnologyEric Hittinger, Assistant Professor of Public Policy, Rochester Institute of TechnologyEric Williams, Associate Professor of Sustainability, Rochester Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/864372017-11-09T04:00:45Z2017-11-09T04:00:45ZWhy solar ‘microgrids’ are not a cure-all for Puerto Rico’s power woes<p>In addition to its many other devastating human consequences, Hurricane Maria left the island of Puerto Rico with its power grid in ruins. Power was knocked out throughout the island, with an estimated <a href="https://www.cnbc.com/2017/09/29/restoring-puerto-ricos-power-is-going-to-be-overwhelming-prepa-says.html">80 percent</a> of its transmission and distribution wires incapacitated. When hospitals and other critical users could not get backup power and water supplies ran low, an extended outage became a humanitarian crisis that has yet to be resolved.</p>
<p>This shameful outcome should have been avoided with strong, swift federal leadership. Yet more than five weeks after the storm, only <a href="http://status.pr/">about 40 percent</a> of the grid has been rebuilt, and service remains unreliable even where power is restored.</p>
<p>As the recovery process inches its way forward, the questions many are asking go like this: Why are we rebuilding the grid to be the same as it was before the storm? Can’t we use this as an opportunity to create a more modern, resilient, renewable power system? Isn’t this the perfect opportunity for an upgrade?</p>
<p>The answer to these questions, from my perspective having worked with and researched the power industry for four decades, has little to do with technologies and everything to do with some nearly insurmountable financial and governance challenges. There is a path forward, but it will not be easy.</p>
<h2>The power system before Maria</h2>
<p>Prior to Maria, Puerto Rico had one of the largest public power authorities in the U.S., known as PREPA, serving a population of <a href="https://www.census.gov/quickfacts/PR">3.4 million people</a> from 31 power plants, 293 substations and <a href="https://www.aeepr.com/INVESTORS/OperationalProfile.aspx">32,000 miles of wire</a>. Almost half its generation was from old, very expensive oil-fired plants, <a href="https://www.utilitydive.com/news/puerto-rico-considers-privatization-for-islands-generation/507999/">resulting in prices about 22 cents per kilowatt hour</a>, among the highest in the U.S. The island has several solar photovoltaic farms but gets about <a href="https://www.eia.gov/state/print.php?sid=RQ">46 percent of its power from oil and only about 3 percent from solar</a>.</p>
<p>At the center of all this is PREPA and its outsized role in Puerto Rico. With US$9 billion of debt, PREPA has been part of the contentious refinancing process that ultimately required congressional action. PREPA is also the largest employer on the island, with strong connections to the island’s leadership, so proposals perceived to adversely impact PREPA can be difficult to enact. Recently the island has established a new energy commission called <a href="http://energia.pr.gov/en/about-the-commission/">PREC</a> with oversight over PREPA’s plans, spending and rates.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/193599/original/file-20171107-1014-1p28rr5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Hurricane Maria knocked out long-distance transmission lines that transmit power from more remote parts of the island in addition to local utility poles.</span>
<span class="attribution"><span class="source">AP Photo/Gerald Herbert</span></span>
</figcaption>
</figure>
<p>The PREC’s efforts at reform underscore the enormous challenges the utility faces. In September 2016 the <a href="http://energia.pr.gov/wp-content/uploads/2016/09/23-sept-2016-Final-Resolution-and-Order-IRP-CEPR-AP-2015-0002.pdf">PREC issued an order directing PREPA</a> to convert some of its oil plants to gas, renegotiate some high-priced renewables contracts and purchase more renewable energy. </p>
<p>In April 2017 PREPA issued a new financial plan with starkly grim prospects: a $4 billion maintenance backlog, the loss of fully one-quarter of its sales in the next 10 years, and <a href="http://energia.pr.gov/wp-content/uploads/2016/09/23-sept-2016-Final-Resolution-and-Order-IRP-CEPR-AP-2015-0002.pdf">continued red ink as far as the eye can see. </a> Meanwhile, renewable power developers who have tried to build plants on the island have encountered great difficulties, as chronicled in <a href="https://www.linkedin.com/pulse/puerto-rico-reconstruction-lowering-electricity-costs-kerinia-cusick/">this blog post.</a></p>
<p>Then, just before Maria, PREPA declared bankruptcy. Maria therefore destroyed the grid of a system that was already bankrupt, having trouble maintaining its service and paying its bills, resistant to renewable interconnections, and politically difficult to reform. </p>
<h2>Proposals for rebuilding with microgrids</h2>
<p>The challenge, then, is to 1) restore energy access as quickly as possible; 2) begin to build a long-term resilient and operable grid; and 3) reform a broken regulatory system. In the wake of the storm, clean energy experts and businesses saw this as the perfect opportunity to start over. </p>
<p>“Puerto Rico will lead the way for the new generation of clean energy infrastructure,” one solar CEO asserted, <a href="https://www.spectrum.ieee.org/energywise/energy/the-smarter-grid/should-a-devastated-caribbean-leap-forward-to-renewable-power-and-microgrids">“and the world will follow.”</a> Elon Musk also <a href="https://twitter.com/elonmusk/status/916234148104118272?lang=en">famously tweeted</a> an offer to solve the island’s energy problems with Tesla solar systems and batteries. </p>
<p>With an array of solar panels and batteries, a group of buildings, such as a hospital, or a neighborhood can power itself and operate independently in the case of an outage with the central grid – called “islanding” in industry parlance. </p>
<p>Provided they can be paid for and operated safely, quickly setting up these solar microgrid systems is an excellent measure that is both stopgap and long-term contributor. These systems can be set up in a matter of days, providing enough power to help neighborhoods with critical power needs, such as cellphone charging, powering cash machines and providing electricity service for health care and first responders. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"922840234143952899"}"></div></p>
<p>However, these systems cost tens of thousands of dollars, and there is currently no substantial way to pay for them other than the kindness of strangers. Three-and-a-half million people would need perhaps 350,000 of these systems – at a price tag in the billions – to provide only a fraction of most families’ power needs. </p>
<p>Even if costs were not a consideration, these distributed systems aren’t a substitute for the grid. Many people think that microgrids don’t need poles and wires, but if they serve more than one building they use pretty much the same grid as we use today. </p>
<p>Once the grid is rebuilt, the new grid-independent systems should then become part of a series of new community microgrids, or networks of multiple solar panel installations backed up by storage. These interconnected systems would be able to “island” together to keep the whole community running at partial if not complete levels of service. With the necessary planning and approvals, new community power organizations could be set up – perhaps separate from PREPA – <a href="http://thehill.com/opinion/energy-environment/353869-puerto-rico-needs-microgrids-and-private-buy-in-for-reliable">to finance the conversion of local grids to a more resilient form</a>. </p>
<p>So there is a path from the current grid to one that is far cleaner and more resilient, but it’s not simple or quick. It would require melding complete and rapid restoration of power with a major infusion of capital.</p>
<p>Changing the base of generation from PREPA’s aging, inefficient fleet to clean sources is an essential part of this path. However, even at an extremely fast pace, it takes months to plan the economics, financing and engineering of this transition. More commonly, it takes years and careful economic and financial planning to raise the billions of dollars of capital needed and then spend it wisely.</p>
<h2>A sustainable, resilient path forward</h2>
<p>Puerto Rico’s citizens have endured great hardship and tragedy. We as a society certainly owe it to them to do whatever we can to lessen the damage from the next hurricane and speed power restoration. However, the path to a sustainable and resilient grid for the island is not as simple as air-dropping solar panels and other equipment onto the island and assuming all will be well. The suggestion that restoring power by replanting the current poles and wires will foreclose a more distributed solution isn’t correct, nor is it the most equitable way to restore power to everyone as quickly as possible.</p>
<p>This isn’t to say that the installation of fully independent solar systems and microgrids should be discouraged in any way. With the important provision that the hardware is maintained properly, the more solar and storage we can get onto the island sooner the better. </p>
<p>At this point, Puerto Rico’s grid is being rebuilt essentially <a href="https://www.eenews.net/stories/1060065805">as it was before</a>.</p>
<p>But even as the grid is rebuilt as quickly as possible, the planning and engineering should begin on how to migrate the grid to smaller sections that self-island. This must include all the main aspects of power system development and operation, including financing, ownership, operation and maintenance of the systems. </p>
<p>The only logical way for Puerto Rico – and every other storm-prone electric system – to become a series of resilient and clean microgrids is to first get the entire grid functioning and then to create sections that can separate themselves and operate independently when trouble hits. </p>
<p><em>Dr. Fox-Penner thanks Scott Sklar, Phil Hanser, Sameer Reddy, Thomas McAndrew and Jennie Hatch for input. All errors are his own.</em></p><img src="https://counter.theconversation.com/content/86437/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Fox-Penner is an academic affiliate of the Brattle Group and Chief Strategy Officer for Energy Impact Partners, which owns interests in a number of clean energy firms listed on EIP's website. He currently sits on the advisory board of EOS energy storage. Peter is also director of the Institute of Sustainable Energy at Boston University, which receives funding from the Hewlett, Barr, Mitchell, and Energy Foundations as well as Bank of America and National Grid.</span></em></p>Yes, Puerto Rico and any other storm-vulnerable location could benefit from on-site solar and battery backup, but it’s unrealistic to say these microgrids are enough to power the island.Peter Fox-Penner, Director, Institute for Sustainable Energy, and Professor of Practice, Questrom School of Business, Boston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/744422017-03-16T19:21:52Z2017-03-16T19:21:52ZSnowy Hydro gets a boost, but ‘seawater hydro’ could help South Australia<figure><img src="https://images.theconversation.com/files/161070/original/image-20170316-20805-19sr0iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Cultana, South Australia: scene of the nation's next big hydro scheme?</span> <span class="attribution"><span class="source">Roger Dargaville</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The federal government has announced a A$2 billion plan to <a href="http://www.abc.net.au/news/2017-03-16/snowy-hydro-scheme-funding-boost-to-secure-electricity-supply/8358502">expand the iconic Snowy Hydro scheme</a>. It will carry out a feasibility study into the idea of adding “pumped hydro” storage capacity, which it says could power up to 500,000 homes.</p>
<p>Hydro is one of the oldest and most mature electricity generation technologies. And pumped hydro storage – in which water is pumped uphill for later use, rather than simply flowing downriver through a hydro power station – is the dominant form of energy storage globally. </p>
<p>But there are limitations to how much freshwater hydro can be accessed, so it’s worth looking at what alternate approaches are available. One promising prospect is to use seawater instead of rivers. This tactic could potentially help South Australia resolve its highly publicised energy problems.</p>
<h2>Hydro basics</h2>
<p>The principle behind conventional hydro power is straightforward: rainwater runoff feeds a river, which is dammed to create a large reservoir of water. This is then gradually released through pipes to a turbine at the foot of the dam, thus converting the gravitational potential energy into electricity. The water then flows on downriver.</p>
<p>Hydro power is fossil-free and also “dispatchable” – it can be turned on or off at will (provided there is water in the dam). This gives it a significant advantage over wind turbines and solar photovoltaic (PV) panels, which produce power only when the wind blows or the sun shines. </p>
<p>Hydro thus makes an ideal partner for wind and solar PV, as it can adjust its output in response to changes in output from these non-dispatchable renewables.</p>
<h2>Pump it up</h2>
<p>Pumped hydro energy storage (PHES) is very similar to conventional hydro power but differs in that rather than being a generator, it’s more accurate to describe it as a battery.</p>
<p>Normally done at smaller scales than conventional hydro, PHES uses excess electricity from the grid (such as during periods of low demand and/or high generation) to pump water uphill from a lower reservoir to a higher one. </p>
<p>Later, this water is released back downhill through the turbine, returning the electricity to the grid when it is most needed – typically during the evening peak. It is this approach that is being considered in the Snowy Hydro 2.0 project.</p>
<p>Pumped hydro storage thus helps to “smooth out” peaks in demand by effectively transferring excess electricity from periods of low demand to periods of high demand. It has a <a href="https://energymag.net/round-trip-efficiency/">“round trip” efficiency of ~80%</a>, which is comparable to that of batteries. </p>
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<a href="https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/161066/original/image-20170316-20793-1okbw4l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The principle of pumped hydro storage.</span>
<span class="attribution"><span class="source">EnergyAustralia</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>PHES is the most common form of grid-connected energy storage in the world, accounting for <a href="https://www.energystorageexchange.org">around 97% of the total</a>. It is often built in partnership with “baseload” power generators such as coal and nuclear plants, to help them vary their output to cope with peaks and troughs in demand. </p>
<p>Australia already has three PHES facilities – at <a href="http://www.snowyhydro.com.au/our-energy/hydro/the-assets/power-stations/">Tumut 3</a> in the Snowy Hydro Scheme, at <a href="https://www.originenergy.com.au/about/who-we-are/what-we-do/generation.html">Shoalhaven</a> in New South Wales, and at <a href="http://www.csenergy.com.au/content-(168)-wivenhoe.htm">Wivenhoe Dam</a> on the Brisbane River in Queensland. </p>
<p>South Australia is arguably the place that is most in need of grid-scale energy storage. Unfortunately, South Australia lacks the rainfall, rivers and mountains to run a conventional hydro system, with or without storage.</p>
<p>However, there is a way to use this technology without rivers and mountains: by using the ocean as the lower reservoir, and building an artificial upper one. </p>
<p>The upper reservoir doesn’t need a river to feed it fresh water; it just needs to be significantly higher than the ocean (that is, there should be a steep slope on or near the coastline, up which the seawater can be pumped). Using seawater also avoids the need to divert freshwater resources into a large reservoir, where a significant amount would be lost through evaporation.</p>
<h2>Testing the technology</h2>
<p>So far, only one seawater PHES installation has been built anywhere in the world – on the island of Okinawa, Japan. It came online in 1999 and was decommissioned in 2016, after Okinawa’s power requirements changed. Seventeen years for a first-of-its-kind project is a significant success. However, the Okinawa project was combined with a coal-fired power station, so linking this technology with intermittent renewables has never been trialled anywhere.</p>
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<a href="https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/161069/original/image-20170316-20784-1hrwho6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Okinawa ocean pumped hydro scheme.</span>
<span class="attribution"><span class="source">CREDIT</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>So could this technology help to ease South Australia’s energy crisis? The Melbourne Energy Institute (MEI) <a href="http://energy.unimelb.edu.au/library/opportunities-for-pumped-hydro-in-australia">report on Pumped Hydro Opportunities</a> identifies several potential seawater PHES locations in South Australia. This includes a very promising site at the northern end of the Spencer Gulf, with significant elevation close to the coast and close to high-capacity transmission lines. </p>
<p>The Department of Defence manages this land, and discussions are ongoing as to how the project might be designed to not interfere with the department’s operations on the site. A win–win development is the primary design aim.</p>
<p>The MEI study suggests that PHES could be delivered at around A$250 per kWh of storage. This compares well with utility-scale lithium ion battery storage, which currently costs of the order of A$800 per kWh, although recent announcements on Twitter from Elon Musk suggest this might be coming down towards A$500 per kWh.</p>
<p>The Spencer Gulf site has the potential to provide at least 100 megawatts of dispatchable generation, effectively making the wind and solar generation in South Australia significantly more reliable. </p>
<p>The Australian Renewable Energy Agency (ARENA) will help fund a feasibility study into the technology, working with partners Energy Australia, Arup and MEI. If the facility is ultimately built, it could become a key element in SA’s bid to avoid future power blackouts.</p><img src="https://counter.theconversation.com/content/74442/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roger Dargaville works with the consortium of EnergyAustralia and Arup that have been funded by ARENA to conduct the PHES feasibility study. He has previously received funding from ARENA to undertake energy system modelling studies.</span></em></p>A planned expansion to the Snowy Hydro scheme is grabbing headlines. But a new plan could build oceanfront hydro power in places without mountains - including South Australia.Roger Dargaville, Deputy Director, Melbourne Energy Institute, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/723532017-02-02T05:14:04Z2017-02-02T05:14:04ZThe government is right to fund energy storage: a 100% renewable grid is within reach<figure><img src="https://images.theconversation.com/files/155286/original/image-20170202-22560-rna6kc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">With the right mix, the grid can go fully renewable for the same cost and reliability as fossil fuels.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File%3ARenewable_Energy_on_the_Grid.jpg">Pixabay/Wikimedia Commons</a></span></figcaption></figure><p>In a <a href="http://malcolmturnbull.com.au/media/address-at-the-national-press-club-and-qa-canberra">speech to the National Press Club</a> yesterday, Prime Minister Malcolm Turnbull declared that the key requirements for Australia’s electricity system are that it should be affordable, reliable, and able to help meet national emissions-reduction targets. He also stressed that efforts to pursue these goals should be “technology agnostic” – that is, the best solutions should be chosen on merit, regardless of whether they are based on fossil fuels, renewable energy or other technologies.</p>
<p>As it happens, modern wind, solar photovoltaics (PV) and off-river pumped hydro energy storage (PHES) can meet these requirements without heroic assumptions, at a cost that is competitive with fossil fuel power stations.</p>
<p>Turnbull and his government have also correctly identified energy storage as key to supporting high system reliability. Wind and solar are intermittent sources of generation, and while we are getting better at forecasting wind and sunshine on time scales from seconds to weeks, storage is nevertheless necessary to deliver the right balance between supply and demand for high penetration of wind and PV. </p>
<p>Storage becomes important once the variable renewable energy component of electricity production rises above 50%. Australia currently sources about <a href="https://www.cleanenergycouncil.org.au/policy-advocacy/reports/clean-energy-australia-report.html">18% of its electricity from renewables</a> – hydroelectricity in the Snowy Mountains and Tasmania, wind energy and the ever-growing number of rooftop PV installations. </p>
<p>Meanwhile, in South Australia renewable energy is already at around 50% - mostly wind and PV – and so this state now has a potential economic opportunity to add energy storage to the grid.</p>
<h2>Pushing storage</h2>
<p>To help realise this potential, in South Australia and elsewhere, the Clean Energy Finance Corporation (CEFC) and the Australian Renewable Energy Agency (ARENA) <a href="https://arena.gov.au/media/arena-and-cefc-support-solutions-for-certainty-of-energy-supply-including-flexible-capacity-and-large-scale-energy-storage/">will spend A$20 million of public funds</a> on helping flexible capacity and large-scale energy storage projects become commercially viable, including pumped hydro and batteries.</p>
<p>PHES constitutes <a href="http://www.energystorageexchange.org/">97% of worldwide electricity storage</a>. The retail market for household storage batteries such as Tesla’s Powerwall is growing, but large-scale storage batteries are still much more expensive than PHES. “Off-river” pumped hydro has a bright future in Australia and many other countries, because there are <a href="http://theconversation.com/how-pushing-water-uphill-can-solve-our-renewable-energy-issues-28196">very many suitable sites</a>.</p>
<p>Wind and PV are the overwhelming winners in terms of new low-emissions electricity generation because they cost less than the alternatives. Indeed, PV and wind constituted half of the world’s new generation capacity installed in 2015 and <a href="http://theconversation.com/wind-and-solar-pv-have-won-the-race-its-too-late-for-other-clean-energy-technologies-61503">nearly all new generation capacity installed in Australia</a>.</p>
<p>Recently, we modelled the National Electricity Market (NEM) for a 100% renewable energy scenario. In this scenario wind and PV provide 90% of annual electricity, with existing hydro and bioenergy providing the balance. In our modelling, we avoid heroic assumptions about future technology development, by only including technology that has already been deployed in quantities greater than 100 gigawatts – namely wind, PV and PHES. </p>
<p>Reliable, up-to-date pricing is available for these technologies, and our cost estimates are more robust than for models that utilise technology deployment and cost reduction projections that are far different from today’s reality.</p>
<p>In our modelling, we use historical data for wind, sun and demand for every hour of the years 2006-10. Very wide distribution of PV and wind across the network reduces supply shortfalls by taking advantage of different weather systems. Energy balance between supply and demand is maintained by adding sufficient PHES, high-voltage transmission capacity and excess wind and PV capacity.</p>
<h2>Not an expensive job</h2>
<p>The key outcome of our work is that the extra cost of balancing renewable energy supply with demand on an hourly, rather than annual, basis is modest: A$25-30 per megawatt-hour (MWh). Importantly, this cost is an upper bound, because we have not factored in the use of <a href="https://theconversation.com/turnbulls-right-we-need-cheap-clean-and-reliable-power-heres-how-71561">demand management</a> or batteries to smooth out supply and demand even more. </p>
<p>What’s more, a large fraction of this estimated cost relates to periods of several successive days of overcast and windless weather, which occur only once every few years. We could make substantial further reductions through contractual load shedding, the occasional use of legacy coal and gas generators to charge PHES reservoirs, and managing the charging times of batteries in electric cars. </p>
<p>Using 2016 prices prevailing in Australia, we estimate that the levelised cost of energy in a 100% renewable energy future, including the cost of hourly balancing, is A$93 per MWh. The cost of wind and PV continues to fall rapidly, and so after 2020 this price is likely to be around AU$75 per MWh. </p>
<p>Crucially, this is comparable with the corresponding estimated figure for a new supercritical black coal power station in Australia, which has been put at <a href="http://www.co2crc.com.au/wp-content/uploads/2016/04/LCOE_Report_final_web.pdf">A$80 per MWh</a>. </p>
<p>Meanwhile, a system developed around wind, PV and PHES and existing hydro can deliver the same reliability as today’s network. PHES can also deliver many of the services that enable a reliable energy system today: excellent inertial energy, spinning reserve, rapid start, black start capability, voltage regulation and frequency control. </p>
<h2>Ageing system</h2>
<p>Australia’s fossil fuel fleet is ageing. A good example is the <a href="https://theconversation.com/closing-victorias-hazelwood-power-station-is-no-threat-to-electricity-supply-66024">pending closure of the 49-year-old Hazelwood brown coal power station</a> in Victoria’s Latrobe Valley. An <a href="https://www.environment.gov.au/climate-change/publications/electricity-sector-emissions-modelling-australian-electricity-generation-sector">ACIL Allen report to the Australian Government</a> lists the technical lifetime of each power station, and shows that two-thirds of Australia’s fossil fuel generation capacity will reach the end of its technical lifetime over the next two decades. </p>
<p>The practical choices for replacing these plants are fossil fuels (coal and gas) or existing large-scale renewables (wind and PV). Renewables are already economically competitive, and will be clearly cheaper by 2030.</p>
<p>Energy-related greenhouse gas emissions constitute about 84% of Australia’s total. Electricity generation, land transport, and heating in urban areas comprise 55% of total emissions. Conversion of these three energy functions to renewable energy is easier than for other components of the energy system. </p>
<p>Transport and urban heating can be electrified by deploying electric vehicles and heat pumps, respectively. Electric heat pumps are <a href="https://theconversation.com/its-cold-in-my-house-and-the-price-of-gas-is-going-up-what-can-i-do-44824">already providing strong competition for natural gas in the space and water heating markets</a>. Importantly, these devices have large-scale storage in the form of batteries in vehicles, and <a href="https://theconversation.com/get-more-out-of-your-solar-power-system-by-using-water-as-a-battery-37807">thermal inertia</a> in water and buildings. Well-integrated adoption of these technology changes will help reduce electricity prices further. </p>
<p>So wind, PV and PHES together yield reliability and affordability to match the current electricity system. In addition, they facilitate deep cuts to emissions at low cost that can go far beyond Australia’s <a href="https://theconversation.com/australias-2030-climate-target-puts-us-in-the-race-but-at-the-back-45931">existing climate target</a>.</p><img src="https://counter.theconversation.com/content/72353/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Blakers receives funding from the Australian Renewable Energy Agency.</span></em></p><p class="fine-print"><em><span>Matthew Stocks receives funding from the Australian Renewable Energy Agency.</span></em></p><p class="fine-print"><em><span>Bin Lu does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Turnbull government is funding energy storage as a crucial missing piece of the electricity grid puzzle. Analysis suggests an affordable, fully renewable grid doesn’t require any heroic assumptions.Andrew Blakers, Professor of Engineering, Australian National UniversityBin Lu, PhD Candidate, Australian National UniversityMatthew Stocks, Research Fellow, ANU College of Engineering and Computer Science, Australian National UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/620322016-07-20T10:07:35Z2016-07-20T10:07:35ZAs nuclear power plants close, states need to bet big on energy storage<figure><img src="https://images.theconversation.com/files/129906/original/image-20160708-24087-e0kbp8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Diablo Canyon nuclear power plant in California is closing and the state has committed to replacing it with greenhouse-free sources of electricity</span> <span class="attribution"><a class="source" href="http://www.flickr.com/photos/52614599@N00/477497335/">Doc Searls</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Pacific Gas and Electric (PG&E) recently started the process of shutting down the Diablo Canyon generation facility, the last active nuclear power plant in California. The power plant, located near Avila Beach on the central Californian coast, consists of two 1,100 megawatt (MW) reactors and produces 18,000 gigawatt-hours (GWh) of electricity a year, about 8.5 percent of California’s electricity consumption in 2015. It has been, up until this point, the single largest electrical generation facility in the state. </p>
<p>Looming over the imminent closure of Diablo Canyon is California State legislative bill <a href="https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201520160SB350">SB 350</a>, or the Clean Energy and Pollution Reduction Act of 2015. The act is a cornerstone of the state’s ongoing efforts to decarbonize its electricity grid by requiring utilities to include renewable sources for a portion of their electrical generation in future years. The mandate also requires utilities to run programs designed to double the efficiency of electricity and natural gas consumption. </p>
<p>But a number of significant unanswered questions remain about this ambitious energy policy, as the planned closing by <a href="http://www.pge.com/en/safety/systemworks/dcpp/newsmedia/pressrelease/archive/pge_calls_state_lands_commission_critical_first_step_for_clean_energy_plan.page">2025</a> of Diablo Canyon illustrates. Can utilities supply electricity around the clock using these alternative generation sources? And crucially, can energy storage technologies provide the power on demand that traditional generators have done?</p>
<h2>Moving away from nuclear power</h2>
<p>Nuclear power plants saw their heyday in the early 1970s and were praised for their ability to produce large amounts of electricity at a constant rate without the use of fossil fuels. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/130743/original/image-20160715-2110-zutfur.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Clinton Power Station in Illinois is one of a number of nuclear plants slated to be shut down largely because of poor economics.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/nrcgov/6517587171/in/photolist-c2mkxN-aVWkAB">Nuclear Regulatory Comission</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>However, due to <a href="http://www.gallup.com/poll/190064/first-time-majority-oppose-nuclear-energy.aspx">negative opinion</a> and costly renovations, we are now observing a trend whereby long-running nuclear power plants are shutting down and very few new plants are being scheduled for construction in the United States. </p>
<p>Utilities are moving toward renewable electricity generation, such as solar and wind, partially in response to market forces and partially in response to new regulations that require utilities to reduce greenhouse gas emissions. In California, in particular, the shift toward renewable energy for market and environmental reasons, along with the public’s negative perception of nuclear energy, has caused <a href="https://www.nrdc.org/sites/default/files/media-uploads/nuclear_power_plant_closures_nrdc_blog_-_table_6-22.pdf">utilities to abandon nuclear power</a>.</p>
<p>While opponents can view the shutdown of nuclear power plants as a health and environmental success, closing nuclear plants intensifies the challenges faced by utilities to meet electricity consumption demand while simultaneously reducing their carbon footprint. PG&E, for example, has pledged to increase renewable energy sources and energy efficiency efforts, but this alone will not help them supply their customers with electricity around the clock. What can be used to fill the sizable gap left by Diablo Canyon’s closing?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/130746/original/image-20160715-2141-yxaet9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Solar power plants that use the sun’s heat to make electricity can store energy as molten salt.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/departmentofenergy/14895879696/">Department of Energy</a></span>
</figcaption>
</figure>
<p>Solar and wind energy sources are desirable as they produce carbon-free electricity without producing toxic and dangerous waste byproducts. However, they also suffer from the drawback of being able to produce electricity only intermittently throughout the day. Solar energy can be utilized only when the sun is out, and wind speeds vary unpredictably. </p>
<p>In order to meet customer electricity demand at all hours, energy storage technologies, alongside more renewable sources and increased energy efficiency, will be needed. </p>
<h2>Enter energy storage</h2>
<p>Energy storage has long been touted as the panacea for integrating renewable energy into the grid at large scale. Replacing the power generation left by Diablo Canyon’s closing will require expansive additions to wind and solar. However, more renewable energy generation will require more storage. </p>
<p>There are many different energy storage technologies currently available or in the process of commercialization, but each falls into one of four basic categories: chemical storage as in batteries, kinetic storage such as <a href="http://energystorage.org/energy-storage/technologies/flywheels">flywheels</a>, <a href="http://energy.gov/eere/energybasics/articles/concentrating-solar-power-thermal-storage-system-basics">thermal storage</a> and <a href="http://energystoragesense.com/superconducting-magnetic-energy-storage-smes/">magnetic storage</a>.</p>
<p>The different technologies within each of these category can be characterized and compared in terms of their: </p>
<ul>
<li>power rating: how much electrical current produced</li>
<li>energy capacity: how much energy can be stored or discharged, and </li>
<li>response time: the minimum amount of time needed to deliver energy. </li>
</ul>
<p>The accompanying figures graphically compare each category of storage and how they perform on these characteristics. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129904/original/image-20160708-24087-15xwlda.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">With chemical storage, energy is contained in the chemical molecular structure of the storage media, such as lithium ion and lead-acid batteries.</span>
<span class="attribution"><span class="source">Eric Daniel Fournier</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129903/original/image-20160708-24079-yeh5oq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">With kinetic storage, energy is stored in physical (i.e., potential) movement of a mechanical system, such as flywheels, compressed air, and pumped hydro(CAES: Compressed Air Energy Storage).</span>
<span class="attribution"><span class="source">Eric Daniel Fournier</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129902/original/image-20160708-24063-ffuitj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Thermal storage, typically utilized in concentrated solar power applications, stores energy in the form of heat, such as molten salt. (TES: Thermal Energy Storage)</span>
<span class="attribution"><span class="source">Eric Daniel Fournier</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129901/original/image-20160708-24071-1k3rlas.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">With magnetic storage, energy is temporarily magnetizing a conductive coil that is later discharged as an electric current, such as superconducting magnets.</span>
<span class="attribution"><span class="source">Eric Daniel Fournier</span></span>
</figcaption>
</figure>
<p>The key challenge that utilities are now faced with is how to integrate energy storage technologies for specific power delivery applications at specific locations. </p>
<p>This challenge is further complicated by the electric power transmission system and consumer behaviors that have evolved based on a energy supply system dominated by fossil fuels. Additionally, storage technologies are expensive and still developing, which makes fossil fuel generators look more economically beneficial in the short term. </p>
<h2>Implementing storage technologies</h2>
<p>Currently in California, energy storage is effectively provided by fossil fuel power plants. These natural gas and coal-powered plants provide steady “baseload” power and can ramp up generation to meet peaks in demand, which generally happen in the afternoon and early evening. </p>
<p>A single energy storage device cannot directly replace the capacity potential of these fossil fuel sources, which can generate high rates of power as long as needed. </p>
<p>The inability to perform a like-for-like replacement means that a more diversified portfolio strategy toward energy storage must be adopted in order to make a smooth transition to a lower carbon energy future. Such balanced energy storage portfolio would necessarily consist of some combination of:</p>
<ul>
<li><p>short-duration energy storage systems that are capable of maintaining power quality by meeting localized spikes in peak demand and buffering short term supply fluctuations. These could include supercapacitors, batteries and flywheels that can supply bursts of power quickly. </p></li>
<li><p>Lower speed energy storage that can supply a lot of power and store a lot of energy. These systems, such as pumped hydro and thermal storage with concentrated solar power, are capable of shifting the seasonality of solar production and servicing the unique power requirements for large scale or sensitive power users in the commercial and industrial sectors.</p></li>
</ul>
<p>This set of storage technologies would have to be linked up in a kind of chain, nested and tiered by end use, location and integration into the grid. Additionally, management systems will be needed to control how the storage technologies interact with the grid.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/130747/original/image-20160715-2144-1kh8u80.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ultracapacitors store energy as batteries do but deliver power differently – in quick bursts, making it potentially suitable for keeping the supply and demand of power in constant balance.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/departmentofenergy/9571202186/in/photolist-fzLUXm-fjm2rU-fzNqj3-oSMctd-fzLUWs-fr6SAE-fzDGpn-fozHUF-8xfatZ-fzUf7W-hKDeTW-fuYMf8-foqTMV-tJcAx2-q4bNom-fzDmgx-eQ3ykP-eQeYdf-hHbTxm-pyFsJ6-czmKfQ-fve3of-gwxniU-fve4m3-jZenfN-osvJ1v-osvfCh-osvxqJ-oSMcgQ-osveR7-oSMchG-fgd9r7-ojHERW-bmK617-fve4d1-fve5dN-fve5nJ-omp8UY-fve32j-fuYM5D-fUTH42-fve54Q-ooeNK2-fj7ghi-orQKdQ-fve4DL-o9SZFR-fve4JE-qkJF4X-oJZZik">Department of Energy</a></span>
</figcaption>
</figure>
<p>Currently without sufficient energy storage in place, utilities now use natural gas to fill in the gaps in electricity supply from renewable sources. Utilities use “peaker” plants, which are natural gas-fueled plants that can turn generation up or down to meet electricity demand, such as when solar output dips in the late afternoon and evening, while producing air pollution and greenhouse gas emissions in the process. </p>
<p>With natural gas consumption for electricity generation on the rise, would it be better to keep nuclear power while energy storage technologies mature? Although less polluting than coal, natural gas produces greenhouse gas emissions and has the potential to cause <a href="https://theconversation.com/californias-aliso-canyon-methane-leak-climate-disaster-or-opportunity-53198">environmentally dangerous leaks</a>, as seen in Aliso Canyon. </p>
<p>With nuclear, it is still not clear what to do with nuclear waste, and the disaster at Japan’s Fukushima nuclear power plant in 2011 highlights how catastrophically dangerous nuclear power plants can be. </p>
<p>Regardless of which situation you believe is best, it is clear that energy storage is the major limitation to achieving a carbon-free electricity grid. </p>
<p>California’s commitment to renewable energy sources has helped shift the state to using less fossil fuels and emitting less greenhouse gases. However, careful planning is needed to ensure that energy storage systems are installed to take over the baseline load duties currently held by natural gas and nuclear power, as renewables and energy efficiency may not be able to carry the burden.</p><img src="https://counter.theconversation.com/content/62032/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eric Daniel Fournier receives funding from the California Energy Commission. </span></em></p><p class="fine-print"><em><span>Alex Ricklefs receives funding from the California Energy Commission. </span></em></p>Can nuclear power plants like California Diablo Canyon be replaced without greatly raising emissions? It’s an open question.Eric Daniel Fournier, Post Doctoral Researcher, Spatial Informatics, University of California, Los AngelesAlex Ricklefs, Research Analyst in Sustainable Communities, University of California, Los AngelesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/591642016-05-12T20:05:29Z2016-05-12T20:05:29ZSouth Australia is now coal-free, and batteries could fill the energy gap<figure><img src="https://images.theconversation.com/files/122244/original/image-20160512-28460-s0atg6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The closure of Port Augusta's Northern Power Plant marks the end of coal-fired generation in South Australia.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/sauer-thompson/6468903835/in/photostream/">Gary Sauer-Thompson/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>South Australia’s last coal-fired power station closed on Monday this week, leaving the state with only gas and wind power generators. </p>
<p>The Northern Power Station, in Port Augusta on the northern end of the Spencer Gulf, has joined Playford B – the state’s other coal-fired power station which has already been retired.</p>
<p>The coal mine at Leigh Creek that supplied brown coal to the power stations <a href="http://www.abc.net.au/news/2016-01-22/sa-outback-town-leigh-creek-for-sale/7107922">also closed</a> earlier this year, so there is no easy option for re-opening the power stations.</p>
<p>The <a href="https://theconversation.com/goodbye-northern-lights-hello-sunlight-58219">immediate impact of the closure</a> was a brief wobble in wholesale electricity prices, with more energy brought in from Victoria’s brown coal power stations (adding to carbon emissions). </p>
<p>But how could it affect the state in the long term? </p>
<h2>Could South Australia run out of power?</h2>
<p>Average electricity demand in South Australia is 1.4 gigawatts, and the state record for peak demand of 3.4 gigawatts was set in January 2011. In the past two years the highest demand was 2.9 gigawatts. </p>
<p>Rollout of rooftop solar panels is one of the reasons demand from the grid has been going down. The impact on the peak demand – the time of day when most people are using appliances – is less clear, because if the peak occurs after sunset, solar panels will not reduce it. </p>
<p>With the closure of the 520 megawatt Northern Power Station, South Australia is left with 2,800 MW of capacity in its gas-fired generators, which can be fired up when needed, and 1,500 MW of wind farms, which of course produce energy only when the wind blows. Most gas generation capacity comes from the Torrens Island A (480 MW) and B (800 MW) installations, built in the 1960s and 1970s, respectively. </p>
<p>There have been discussions about retiring Torrens Island A (it was mothballed for a period in 2014), but the departure of Northern appears to have delayed those plans.</p>
<p>The state also has a total of about 600 MW of <a href="http://pv-map.apvi.org.au/postcode">rooftop solar</a>, but, as noted above, this technically counts as reducing demand rather than adding to supply. </p>
<p>South Australia is also connected to Victoria via two transmission lines, one at Heywood (recently upgraded to 650 MW) and one at Murray Link (220 MW). This gives the state access to a potential 870 MW of Victorian power.</p>
<p>If South Australia gets close to record demand, the state clearly outstrips the capacity of the local gas generators. If the wind isn’t blowing, then the state will depend on the interconnectors. </p>
<p>But there is an unfortunate factor that transmission lines tend to <a href="https://www.nccarf.edu.au/sites/default/files/attached_files_publications/QUT_2010_Southern_cities_heatwaves.pdf">fail under very high temperatures</a>, which correspond to the times of highest demand.</p>
<p>It may sound unlikely, but South Australia is at risk of failing to meet demand. This would depend on a very specific set of circumstances:</p>
<ul>
<li><p>record demand (despite the increase in rooftop solar reducing demand)</p></li>
<li><p>no wind</p></li>
<li><p>failed interconnectors (or failure of local generators). </p></li>
</ul>
<h2>A role for storage</h2>
<p>This situation means the state is the most likely location for investment in storage. The Australian Renewable Energy Agency (ARENA) recently published a <a href="http://arena.gov.au/project/energy-storage-for-commercial-renewable-integration/">report on storage</a> that identified several locations in South Australia that would be logical places to install commercial-scale batteries.</p>
<p>We at the Melbourne Energy Institute have previously written about <a href="https://theconversation.com/pumped-hydro-energy-storage-making-better-use-of-wind-18565">pumped hydro storage</a> options, in particular the <a href="http://energy.unimelb.edu.au/__data/assets/pdf_file/0007/1526587/Opps-for-pumped-hydro-in-Australia.pdf">novel approach</a> of using salt water. This may be of particular use in a very dry state such as South Australia.</p>
<p>But batteries are only going to be attractive investments if there is sufficient volatility in the market to provide arbitrage opportunities. Arbitrage, put simply, is the process of buying low and selling high. </p>
<p>Storage systems need be able to be charged with low-cost energy (for instance, overnight when demand is low, or when the wind is blowing hard) and dispatch the power back onto the grid at a sufficient profit to cover the investment costs.</p>
<p>We are currently in a low-demand period of the year (the shoulder seasons have both low heating and cooling requirements). This means there has not been much shift in electricity prices coming out of South Australia with the removal of Northern. It might not be until next summer, with hot temperatures and increased demand from air conditioners, that we are able to see the true magnitude of the impact of this exit on electricity prices and market volatility.</p>
<p>To date (only a couple of days since the closure), the wind has been blowing hard and there has been no need to increase substantially the generation from other fossil generators. Likewise, there have been <a href="http://electricity.earthsci.unimelb.edu.au/dispatch_7days.jpg">no discernible shifts</a> in the spot market prices. </p>
<p>Finally, the impact on carbon emissions will also be interesting. This will depend on how the remaining generators respond. The gap left by Northern may be filled with South Australian gas, in which case total emissions will fall, but more likely the gap will be filled with Victorian coal power via the interconnectors, resulting in no reduction in net emissions. </p>
<p>We will know the net result in due course – watch this space.</p><img src="https://counter.theconversation.com/content/59164/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Roger Dargaville receives funding from the Australian Renewable Energy Agency (ARENA). </span></em></p>Closure of the state’s last coal power station will leave a potential gap in the electricity supply.Roger Dargaville, Deputy Director, Energy Research Institute, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/514962015-12-03T11:08:49Z2015-12-03T11:08:49ZRedox flow batteries could be the answer to our energy storage needs<figure><img src="https://images.theconversation.com/files/104122/original/image-20151202-22467-1y6f69u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Sinisha Karich/shutterstock.com</span></span></figcaption></figure><p>How to store energy has become as important a challenge as how to generate it. The types of batteries that power our electronic devices or vehicles are tried and tested, but they’re not suitable for really large-scale energy storage – the sort of batteries that can power whole communities, key emergency services and critical infrastructure. </p>
<p>Making the jump from small to large capacity batteries that could provide back-up for the national grid in times of high demand has proved difficult. Lithium ion batteries offer high power density in a compact size and have many uses, although concerns have arisen about their <a href="http://batteryuniversity.com/learn/article/safety_concerns_with_li_ion">potential to cause fires</a>. Engineers usually encase the battery in a fire-proof cell, but this eats into the battery’s lightweight advantage. </p>
<p>One technology focused on meeting large power needs is the <a href="http://energystorage.org/energy-storage/technologies/redox-flow-batteries">redox flow battery</a>, with <a href="http://www.rongkepower.com/">Ronke Power</a>, launched at the Dalian Institute of Chemical Physics in China 12 years ago, a leading player. </p>
<p>Like other batteries, a redox flow cell contains electrolyte solutions and a positive and negative terminal, around which electrons flow when the circuit is connected. If the battery is not charged, the electrolyte gradually loses its stored energy. How the redox flow battery differs is that in order to maintain energy, fresh electrolyte is continuously pumped into the battery. </p>
<p>The battery, or converter as it is called, is supplied with positive and negative electrolyte solutions held in separate plastic storage tanks. When the electrolyte solutions are supplied to the converter, power is instant and can be varied simply by controlling the flow of electrolyte.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=436&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=436&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=436&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=548&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=548&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104120/original/image-20151202-22439-3vhe4b.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=548&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A vanadium-based redox flow battery.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Vanadium_battery.svg">Paj.meister</a></span>
</figcaption>
</figure>
<p>An important advantage of redox flow is that it’s relatively low-cost. The converter stays the same size for a given power density, but the duration power can be extended from four hours to more than 12 hours simply by installing larger plastic storage tanks to hold more electrolyte. The electrolytes’ charge can be regenerated through connection to electrical power to reverse the discharge process – in other words, when mains power is connected the tanks charge, and when mains power fails the tanks discharge as back-up. </p>
<p>These are both practical and economical batteries. Several types exist such as zinc bromide, polysuplhides, and zinc-cerium, but it’s vanadium-based batteries that are now most common, for a number of environmental and cost considerations.</p>
<p>A drawback compared with lithium ion batteries is the energy density – the size of the installation is large, although I see this as a positive way to differentiate those uses below 20MW (small, lithium ion batteries), and larger installations of redox flow batteries providing 20MW or more.</p>
<h2>Changing times call for energy storage</h2>
<p>Several changes are occurring that make the need for high-capacity energy storage more pressing. Globally, people are moving from rural areas into cities, concentrating the population in smaller areas and placing greater strain on the energy grid. This means that any disruption has a greater impact and is felt by more people, with an economic impact from the effects on industries such as aerospace, petrochemicals, oil and gas, and engineering.</p>
<p>Another change is the surge in renewable energy generation, part of the jigsaw that will ensure sustainable, reliable and competitive energy production into the future. Booming installations of wind and solar generation have brought about a pressing need to integrate these irregularly generating energy sources into the grid. </p>
<p>It’s particularly obvious, however, that wind energy generated overnight when power demand is low is wasted. If wind farms had proper energy storage systems, this energy could be stored until it was needed, meaning the capital invested in wind farms could be more fully used, something which could <a href="http://www.technologyreview.com/news/514331/wind-turbines-battery-included-can-keep-power-supplies-stable/">double the power generated</a>. </p>
<p>Other systems could also benefit, such as municipal waste systems based on anaerobic digestion of organic waste into methane gas. This natural process continues around the clock, so if power was generated from gas continually and linked to energy storage it would provide the same benefits. Building an energy storage system that’s high-capacity and financially viable is key.</p><img src="https://counter.theconversation.com/content/51496/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Atkins does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We already have them in many sizes – but we’re still looking for a battery to store truly large amounts of energy.Martin Atkins, Professor of Green Chemistry, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/411312015-05-04T17:47:57Z2015-05-04T17:47:57ZHas Tesla cracked the grid energy storage problem?<figure><img src="https://images.theconversation.com/files/80173/original/image-20150503-23887-1vhq8ke.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fancy a home battery with your battery-powered car? </span> <span class="attribution"><a class="source" href="http://www.teslamotors.com/powerwall">Tesla Motors</a></span></figcaption></figure><p>Has Tesla finally done it? Has it finally plucked out the long-standing thorn in the side of renewable energy – the need for cost-effective ways to store electricity? With the announcement of the Powerwall storage system, Elon Musk & Co would certainly like us to think that they have.</p>
<p>There is a lot to admire about the Powerwall, at least as it was first <a href="https://vimeo.com/126695958">presented</a>. It’s small, sleek and clearly designed with aesthetics in mind, not unlike the game-changing hardware produced by that <em>other</em> hot California technology company. </p>
<p>This is not my father’s propane backup generator, which sits in a big box a hundred feet from his house. It is definitely not the diesel generator we had when I was a kid, which looked like (and basically was) a mutant lawnmower engine. </p>
<p>Tesla said the price for the batteries alone is a few thousand dollars but the total is substantially higher when installation and an inverter to make household AC power out of battery DC power are included. Partner SolarCity <a href="http://www.bloomberg.com/news/articles/2015-05-01/solarcity-taking-orders-for-tesla-batteries-starting-at-5-000">said</a> it will sell the battery pack for $7,410 or lease it over nine years for $5,000.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=421&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=421&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=421&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=529&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=529&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80174/original/image-20150503-23856-1gzpiqo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=529&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A two pack of Tesla home batteries.</span>
<span class="attribution"><a class="source" href="http://www.teslamotors.com/powerwall">Tesla Motors</a></span>
</figcaption>
</figure>
<p>To add to the excitement, one utility, Green Mountain Power in Vermont, announced it would be happy to sell the <a href="http://geekmountainstate.com/2015/05/01/green-mountain-power-to-offer-tesla-home-battery/">Powerwall directly to its customers</a>. This is a sign not only that utilities are taking the potential of the Powerwall seriously, but that they may be trying to figure out a way to profit from <a href="https://theconversation.com/tesla-batteries-just-the-beginning-of-how-technology-will-transform-the-electric-grid-40142">potentially disruptive technologies</a>. (Full disclosure: Green Mountain Power has funded some of my university research in the past.)</p>
<p>But for all the buzz around Powerwall, home batteries – even sleek, more-affordable ones – face some hurdles. Unlike a shiny new iPad or iPhone, batteries are still a long way from becoming the next must-have consumer item.</p>
<h2>Who will bite first</h2>
<p>The Powerwall is most likely going to see its biggest initial domestic sales in the same markets that other energy storage companies are targeting – Hawaii, California, New York City and military bases. California is currently a hot market for energy storage because of how the state has chosen to subsidize energy storage technologies. Tesla has already been a big beneficiary.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/80175/original/image-20150503-23877-gvz5t6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tesla batteries: not your father’s basement generator.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dvanzuijlekom/11340173456/in/photolist-ih6mu1-7k5zrL-hjF3Rx-ji9tqo-dZhzkg-di2zCs-5sU6Z-5S8zNE-bymxJM-5mhBKx-5mmWxj-5mmYtf-5mmSEA-5mhHyg-fSWPYk-5mhFBM-5mmUAd-yL73j-91QwBD-emhYPi-88fcF1-zHqi9-e4kwFj-nTniML-7oiwxu-9yUywN-hokLfQ-dMWxZ5-e38KjV-7HbXY4-obfodE-84f7VU-3HyeSS-7HfSiA-h76nqN-81VLnb-81SBTD-7oiwSQ-7oeEf4-81VLvy-7oeCka-81SBZk-81VLqA-7HfRUY-nUGrS-81VLt5-7oixto-amVAHj-7HfRLU-81SBWt">Dennis van Zuijlekom</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These subsidies, however, can and do disappear sometimes. As this <a href="http://www.greentechmedia.com/articles/read/how-teslas-energy-storage-play-could-take-flight-or-founder">article</a> reports, California is mulling significant changes to its energy storage subsidy scheme. When they do disappear, so can the value of the technology being subsidized. Just ask the providers of “demand response,” whose revenue streams for peak-time electricity reductions were severely disrupted by a successful court challenge to the pricing system established by <a href="http://www.ferc.gov/industries/electric/indus-act/demand-response.asp">federal regulators</a>. The Supreme Court has <a href="http://www.reuters.com/article/2015/05/04/us-usa-court-electricity-idUSKBN0NP17020150504">agreed to take up this case</a>, but the regulatory uncertainty has already affected business models and the functioning of regional power markets.</p>
<p>To keep prices down, Tesla as well as current and future competitors will have to spend lots of time and money lobbying the state to keep the subsidy system in place.</p>
<p>States with a large difference between peak and off-peak prices, including California again, are also a good potential market for low-cost home energy storage. Charge at night when electricity is cheap and discharge during the day when it’s expensive.</p>
<p>This “energy arbitrage” strategy, however, has never worked for the energy storage industry, and it’s unlikely to work for the Powerwall either. The type of charge/discharge cycle for energy arbitrage would probably affect the long-term health of the battery system, meaning more frequent replacement (Tesla is saying that the Powerwall will have a warranty of ten years, though on what terms we don’t yet know).</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/yKORsrlN-2k?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Tesla Motors CEO Elon Musk pitched the home batteries as a way to cut carbon emissions by storing rooftop solar power.</span></figcaption>
</figure>
<p>With enough battery energy storage following the energy arbitrage model, the cost of grid-produced power during the day would plummet because of lower demand. And the cost of power during the evening would rise due to higher demand for charging. On a pure cost basis, this would eat away at the large price differential that built the energy arbitrage idea in the first place.</p>
<p>Moreover, potential buyers seeking to integrate the Powerwall with solar photovoltaic (PV) systems wouldn’t even follow the energy arbitrage strategy; they would do exactly the opposite, charging from rooftop PV panels during the day and discharging at night. Even in California, the economics of doing this, versus just leaning on the power grid at night, are pretty rotten.</p>
<h2>Paying for backup</h2>
<p>Tesla is also trying to sell the Powerwall as a reasonably priced form of backup power, in case of emergencies on the grid. (Remember Hurricane Sandy, anyone?) While it remains to be seen whether it can compete with other backup generator technologies, this customer segment is, in some sense, just what Tesla needs: high-income households to serve as early adopters because they can afford to place a premium on having electricity service during blackouts.</p>
<p>The Powerwall, for all its novelty, is a reminder of how energy storage is still ripe for maturity and how, as an industry, it is still searching for the right business model.</p>
<p>As <a href="http://cleantechnica.com/2015/03/04/energy-storage-could-reach-cost-holy-grail-within-5-years/">these</a> <a href="http://www.nature.com/nclimate/journal/v5/n4/pdf/nclimate2564.pdf">articles</a> show, the costs of energy storage are falling dramatically, although the “balance of systems” costs, which include the inverter, other equipment and installation, still have a ways to catch up.</p>
<p>Even so, energy storage has got to move beyond simply lowering energy cost to have broad market viability. The fall in the price of computers and smartphones was itself revolutionary because these devices did things that nothing else could. In the developed world where the centralized grid is already present and usually reliable, there are plenty of alternatives to the Powerwall and its competitors.</p>
<hr>
<p><em>This article has been updated with the latest available pricing information. To read more about the changing electric grid, see:</em></p>
<ul>
<li><p><a href="https://theconversation.com/why-rooftop-solar-is-disruptive-to-utilities-and-the-grid-39032">Why rooftop solar is disruptive to utilities – and the grid</a></p></li>
<li><p><a href="https://theconversation.com/tesla-batteries-just-the-beginning-of-how-technology-will-transform-the-electric-grid-40142">Tesla batteries: just the beginning of how technology will transform the electric grid</a></p></li>
</ul><img src="https://counter.theconversation.com/content/41131/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Seth Blumsack has received research funding from the U.S. National Science Foundation, Department of Energy, Environmental Protection Agency, the Commonwealth of Pennsylvania, Ford Foundation, PJM Interconnection, LLC, Green Mountain Power, the Williams Companies and the Marcellus Shale Coalition.
He has performed consulting work for Vermont Energy Investment Corporation, Vermont Electric Cooperative, Environmental Protection Agency, Los Alamos National Laboratory and Department of Energy. He has also appeared as an expert witness on behalf of numerous state public utility commissions.
Dr. Blumsack is currently a visiting researcher at the Santa Fe Institute</span></em></p>As it’s done with its electric cars, Tesla will need to rely on well-heeled early technology adopters and friendly regulations to sell lots of home batteries.Seth Blumsack, Associate Professor, Penn StateLicensed as Creative Commons – attribution, no derivatives.