The primary driver should be emissions targets not quotas and subsidies for preferred technologies. That way nuclear and carbon capture (if viable) get a look in. An oddity is that a report to the RET Review concluded the cost of CO2 avoided by the RET was $59 per tonne. When carbon tax was repealed the official price was $25.40. If Abbott's election can be taken as vote against carbon pricing it is odd that opinion surveys find 65% support for the RET. I suspect that is in part due to fears of losing the feed-in tariffs for home solar, a state government not federal policy.

I would drop the RET altogether and replace it with a tough ETS whereby emissions have to shrink 1% a year. Then we'd see if wind and commercial solar stood on their own merits as emissions reducers. At the moment our emissions are up, perhaps proving the RET is ineffective for that purpose.

Dear Taswegian,

While the CO2 story is a bad hoax, non-renewable still means non-renewable: what we take from the earth now, which accumulated there over billions of years, whatever intelligent species will come after humans are gone, will no longer be able to use. What right has the human race to plunder the earth this way, taking it all in ~200 years?

Perhaps this explains the difference in percentages between the smaller number concerned about CO2 and the larger number concerned about depleting the earth of its energy resources?

When David Leyonhjelm says "Nobody believes this is possible" what he really means is he can't see how it can be done. Or possibly he just thinks it shouldn't be done and creating the illusion of impossibility is the most effective way to get others to agree. But in reality the main thing preventing us from reaching the target is the politicians removing the incentive to!

If retailers cannot purchase enough certificates, the legislation requires that a penalty charge of $65 per MWh be imposed. That's 6.5c/kWh. How can that "nearly triple the cost of the scheme to electricity retailers"? And when have retail margins ever been part of the cost to retailers?

Hydro generators certainly should be in the RET, but broadening the scheme should not be used to reduce the effective target. We should commit to add 25 TWh in 5 years. And we should fund it with concessional loans to ensure that it results in cheaper electricity.

Taswegian do you really believe the authority claiming to state our emissions can be trusted. Obviously they could cease to exist if emissions are going down.

When the once trusted Bureau of Meteorology can no longer be trusted to call a category 3 cyclone a cat 3, but get caught trying to label it a cat 5, it becomes very hard to believe the pronouncements of a body with high vested interested.

Hell I can remember when you could trust the CSIRO, & believe it implicitly. You could once actually watch the ABC news, & believe their presenters.

I recently saw a satellite generated map of the CO2 emissions worldwide. The biggest plume of CO2 from any part of the planet came from the Amazon jungle. Australia was near the lowest emitter, but also very low, was the eastern half of the USA.

This didn't preach the right story, so was quickly discarded by academia to please their greenie mates. Hell we wouldn't want it realised by the public, that we could reduce CO2 emissions by bulldozing all that horrible rain forest, & building an industrial estate, now would we?

Hasbeen, do you actually believe, or even just think it possible, that we could reduce CO2 emissions by bulldozing all that horrible rain forest, & building an industrial estate?

Destruction of the rainforest is one of the biggest emitters of CO2, and also a big emitter of methane. Rainforests are big absorbers of CO2 - we once thought that once fully established a rainforest's effect is neutral, but we now know that not to be the case – it keeps on growing. However even in the Amazon jungle, forest fires do occasionally occur – and when that happens there are big CO2 plumes.

Our electricity supply is 87% fossil fuelled, 13% renewable of which half or so is 20th century built hydro. I'm fairly sure no new large hydros will ever be built so it comes back to wind and solar, 1.5% and 2.9% of our 2013 electricity. Reference BREE Energy in Australia 2014 Table 8.

Apart from electricity there is heating both industrial and domestic as well as transport fuels, overwhelmingly oil based. In future electricity may take over some but not all heat and transport tasks. If you think the small amount of wind and solar can expand say twenty fold but with more reliability I think this flies in the face of the evidence.

Side note; under the RET hydro is not eligible for the REC subsidy of around $40 per Mwh if built before 1997. Somehow some circa 1975 built hydros have wangled it. I think the Commonwealth Auditor General should investigate.