A great write-up as always, thanks for putting in the time and...

A great write-up as always, thanks for putting in the time and sharing this.

The fact of the matter is - to reach the 50% QRET, additional deep storage is necessary. This is evident in the current generation behaviour of Wivenhoe, where there has been a clear choice to pump and generate at half capacity, for twice as long.

Despite Wivenhoe being used at higher capacity factors, solar spot price suppression in Queensland is occurring for hours on end (sometimes as long as 9am - 4pm). That's 7 hour of cheap pumping. With a return trip efficiency of ~80%, that yields at least 5 hours' worth of generation. This could be used for 5pm - 8pm in the evening peak, and 7am - 9am the following day during the morning peak. The chart below shows the daily average spot price for Queensland during June 2020, and shows perfectly the opportunity here.

I agree that batteries are an excellent investment, but deeper storages will remain a vital part of the transition. In addition as you mentioned, pumping means less curtailment. Curtailment is also happening for hours on end, a problem which 1-2hr battery storages will struggle to resolve.

With rooftop PV still making strong gains, even if utility-scale solar projects are no longer being built, low daytime spot prices are here to stay. This is a jobs-building long-term investment for the state, and a key project to enable the 50% renewable energy target to be met. It would be very short-sighted for the state government to allow it to fall over and miss out on rural Qld jobs.

The economics of the project's viability remains strong, and that's why I'm still confident to put my money behind Genex and see this project come to fruition.