The trouble with "renewable energy targets" is that "renewable energy" (which is a vague buzzword with no scientifically meaningful definition) is not the fundamental objective.

The fundamental objective is to replace coal and gas-fired generation with clean energy generation which can provide energy on the same scale with the same high capacity factor, and to do it at the lowest possible cost.

The fundamental objective is not to spend the maximum possible amount of money on solar cells or wind turbines - it is to do the coal replacement job at the lowest possible cost.

Replacing coal-fired generators with gas certainly isn't perfect as far as energy costs and greenhouse gas emissions are concerned. But actually replacing coal-fired generators with gas turbines is greatly preferable to building some solar cells which are not actually replacing coal-fired plants.

Replacing the large-scale, high-capacity-factor energy output of a coal-fired plant with clean energy should be incentivised - either with a tax on greenhouse gas emissions, or by paying an incentive for clean, scalable, high-capacity-factor non-fossil-fuel energy delivered to the grid.

It is a big mistake, however, to choose solar cells and wind turbines as the "allowed" definition of clean energy that you're going to subsidise or incentivise, and ignore hydroelectricity, nuclear energy, geothermal, tidal or any other energy systems, especially when solar energy and wind energy have amongst the lowest capacity factors and lowest scalability and highest cost of any non-fossil-fuel energy systems and hydroelectricity, nuclear energy and geothermal have amongst the highest capacity factors, highest proven scalability, lowest costs and already account for essentially all of today's non-fossil-fuel energy generated.

Gas should be incentivised relative to coal - a little bit, not as much as non-fossil technologies - because it is a little bit better than coal.

The incentives should not be biased in favour of certain technologies on unscientific grounds just because some people seem to think that wind energy or solar energy has some kind of intrinsic, metaphysical "goodness" which transcends any rational scientific analysis of the fitness of different energy systems for scalable coal replacement.

The incentives should not be technologically neutral either - they should be technologically biased, in favour of those technologies which are best proven to do the job of scalable, high-capacity-factor replacement of fossil fuel plants.

Both Garnaut and the Productivity Commission suggest the RET double dips on top of the carbon price. What is so special about renewable as opposed to say nuclear? Like living in caves modern society may have become so demanding that renewables are simply not up to the task. Some suggest 'renewable' really means 'minor renewable with major gas' which implies wind and solar will struggle as gas depletes. SA power prices hint at this.

The claimed reduction in spot prices are purely an artefact of the RET the same way off-peak water heating is an artefact of coal baseload. Thankfully it gives back some of the REC subsidy. Remember the RET is enforced via penalties so the retailers are obliged to take wind and solar to meet the target. It's not an arms length deal. The backup generators currently lack the legal power to charge a stabilisation fee during enforced downtime. Perhaps we need a RET = reliable energy target with even more subsidies.

If we had a strict ETS without freebies (free permits, dodgy offsets) the market would decide the least cost combination. That with nuclear in the mix is the way to go. If renewables are so good why do they even need a mandate?

This article shows little appreciation of business fundamentals or power system operation.
A base-load generation capacity is needed independent of wind or solar which are unreliable,un-dispatchable and can be unavailable when most needed.
See: http://www.ref.org.uk/publications/217-low-wind-power-output-2010
" It is now well known that low wind conditions can prevail at times of peak load over very large areas. For example, at 17.30 on the 7th of December 2010, when the 4th highest United Kingdom load of 60,050 MW was recorded, the UK wind fleet of approximately 5,200 MW was producing about 300 MW (i.e. it had a Load Factor of 5.8%). One of the largest wind farms in the United Kingdom, the 322 MW Whitelee Wind Farm was producing approximately 5 MW (i.e. Load Factor 1.6%).
Load factor in other European countries at exactly this time was also low. The Irish wind fleet was recording a load factor of approximately 18% (261 MW/1,425 MW), Germany 3% (830MW/25,777 MW), and Denmark 4% (142 MW / 3,500 MW).4
Such figures confirm theoretical arguments that regardless of the size of the wind fleet the United Kingdom will never be able to reduce its conventional generation fleet below peak load plus a margin of approximately 10%."

It is a furphy to say that feeding solar power into the grid will lower overall prices as the 24/7 power operators will amortise the cost via higher spot pricing. The argument that German solar is lowering prices
is odd because German electricity prices are the highest in Europe to pay for economically disastrous renewable energy targets.
The French who are relatively uninvolved in the green nonsense and have opted to go nuclear a long time ago have pricing at 40% of German rates.

The British and the French have been experimenting with Wave Power generation for well over eighty years and as will be found to be the case with socalled renewables in the current context of solar panels and wind turbines, they have found no solution to the poroblems of wear and disfunction. S0olar cells will not last forever and will require constant cleaning. Wind power has already been shown to be almost totally unsatisfactory. NONE of thewse woulkd even get off the ground without the Carbon tax and massive subsiidies.

Solar panels for homes for instance require about a 60% minimum subsidy on installation before people will contemplate an installation plus a cost here in Queensland to the other consumers who can't afford Solar Panels of about 2.2 times the cost of power from coal, even after the recent rises because of the cost on infra-structure infra structure. i.e. People are paid 44 c per kWh for power going back onto the grid, which with losses and the increased inefficiencies introduced by having thousands of 2 kW generators feeding randomly onto the grid the price to other consumers is more like 70 c per kWh while the flat rate for coal fired power is currently 19.5 c per kWh.

The only reason the electricity prices are rising here in Queensland, is because the "smart", previous, Bligh government who broke the State (even though it sold off State assets for recurrent expenditure), demanded that all of the reserves from the State owned power authorities ("companies") pay to the government ALL of their monetary reserves which would have been used now to pay for expanding deliveries and replacing old power lines with good, but certainly not 'gold plated", new ones. The power lines required to bring electricity from what might become wind turbines and solar panels will be another drag on the coffers and losses of power along long lines will reduce efficiencies even more.

The only alternatives to coal are nuclear and hydro, boith of which are violently opposed by the Greens.