The ongoing nuclear crisis at the Fukushima Daiichi plant has caused some to question the impact of various power generation sources on our environment and lifestyles.
So is there any such thing as “free”, “zero-impact” or “safe” energy? Unfortunately, the answer is “no”.
But by placing as much emphasis on the path to clean energy as on the goal, with compromise rather than fundamentalism, we can certainly reduce our impact.
Each source of energy requires an investment to extract and each brings environmental impacts. But the magnitude of these costs, impacts and risks vary dramatically from place to place.
This is why there is no “silver bullet”, and why it’s necessary for society to invest, not only in the development of a wide range of technologies, but also in the assessment of their impacts and how these can be minimised.
Renewing our energy profile: a familiar challenge
The development of new technologies to avoid adverse environmental impacts is as old as human society. The burning of coal was introduced to address the impact of deforestation caused by the use of wood as fuel.
Following the discovery of coal, evolving legislation has driven the development of technologies to mitigate emissions. First smoke (for the London Smog), then carbon monoxide and the oxides of sulphur and nitrogen, and now carbon dioxide emissions have been regulated over time.
But there are two key differences that make the introduction of legislation to control CO2 much more difficult than that of the other pollutants.
Legislation to control air pollution has historically been driven by the local effects of air pollution, such as smog, which are within the jurisdiction of governments.
In contrast, carbon dioxide has no local effect (indeed we all breathe it out) - it only has a global effect.
Unfortunately, human society is much poorer at addressing global issues, with international bodies having much weaker governance power than national ones.
And the mitigation of CO2 is more expensive than other pollutants. Of course, the cost of mitigation is still significantly less than the long term cost of doing nothing, but the short term costs lead to significant political barriers.
Hence there is an imperative to find low cost pathways to a cleaner energy future.
To every energy source its cost
Why is there no such thing as zero-impact energy? Because all technologies require resources and energy to manufacture and operate.
This is true whether the technology harvests wind, wave, solar energy, biomass, fossil fuels or uranium. Thermal power stations, which are presently the most efficient and cost effective, produce waste heat.
This results in a trade-off between efficiency and water consumption.
Even wind and wave power have some adverse impacts, notably with noise and impacts on bird populations for wind, and on coastal eco-systems for wave.
And across the energy network, each technology impacts on the others. In our present energy networks, demand is uncontrolled and there are limited opportunities for cost-effective storage. So the addition of intermittent energy generation will impact adversely on the efficiency and total cost of the generation network.
Finding energy solutions: the path is the goal
The complex and coupled nature of energy systems combined with the highly localised differences in costs of clean energy means that, to amend a Buddhist maxim, the path to sustainable energy becomes the goal.
It’s widely accepted that putting a price on carbon dioxide is a key step along this path - to provide an economic driver for it.
Of course, the new technologies needed to support the transition will span the entire energy chain from generation, through distribution to end-use.
However the transition to cleaner sources of energy will take many years and fossil fuels will continue to provide the majority of our energy until at least 2050.
On this basis, another key step in the pathway is the need to replace old and inefficient plants with the most efficient that are available.
A third is the use of hybrids, because it is typically twice as cost-effective to combine renewable and fossil fuels into the same power generator than it is to build and operate two stand-alone generators.
Hybrids reduce cost for the renewable plant, both because they can share infrastructure, such as turbines and condensers, and also because they can increase the efficiency of the renewable component.
We should also avoid the temptation to think that it is better to build stand-alone renewable plants simply because they have the appearance of being cleaner.
We need to invest wisely in opportunities that give the most cost-effective path to greenhouse mitigation and support local initiatives with good opportunities for growth.