Another trip down the rabbit hole

The Australian energy minister's transition policies are like something out of Lewis Carroll's Alice books: it seems the harder Chris Bowen tries to run towards his destination, the further away from it he gets.

Take his newer and harder-running Capacity Investment Scheme (CIS), a development on his original scheme announced in December 2022.

It promises a lot but is likely to be nothing more than a poorly shuffled deck of cards.

The original scheme was to provide 6 gigawatts (GW) of dispatchable renewable power, and the results of the first pilots have just been announced. The first participants in this scheme will be six projects providing 1.075 GW of "reliable capacity" in New South Wales.

The revised plan expands the scheme to 32 GW all-up, with 9 GW of dispatchable capacity and 23 GW of variable capacity. This is meant to meet the government's aim that 82 percent of electricity generation will be renewable by 2030. The numbers sound impressive, but what do they really mean?

Australia currently produces 273,265 gigawatt hours of power every year. Of that, 88,208 GWh is renewable.

To get to 82 percent, the government needs to generate another 135,869 GWh with renewables.

On average that is 15.51 GW every hour.

So, you might be thinking that Mr. Bowen's 32 GW capacity will more than do the trick, in which case you would be wrong.

As is well known by now, the sun doesn't always shine, and the wind doesn't always blow.

If 32 GW were all wind capacity, it would only produce 11.2 GW on average each hour, varying between zero and 32 GW. If it were all solar then the average figure would be 6.4 GW.

In fact, not only will the capacity be a mix of wind and solar, but it also includes 9 GW of batteries. They complicate the picture because they store energy, they don't produce it, and they will need to get that energy from variable sources, further reducing their capacity utilisation.