South Australia solar shines out of Snowy's pumped hydro modelling | RenewEconomy

South Australia solar shines out of Snowy’s pumped hydro modelling

The modelling used to promote the multi-billion Snowy 2.0 pumped hydro project appears to assume that in South Australia, solar power is produced during the night.

Enel Green Power's Bungala solar farm.

It took nearly a week, but RenewEconomy finally got hold of the 14-page information pack distributed to journalists last Tuesday by the federal government and its wholly owned Snowy Hydro energy utility at the official launch of the Snowy 2.0 pumped hydro project.

The Coalition government announced that it would inject $1.4 billion into Snowy Hydro to support the project – or at least enable the company to pay some dividends in coming years while it funded the multi-billion dollar venture. But the final costings, and the business case, were not revealed.

In its stead was the 14-page document, which assured readers that the status of the idea embraced by Malcolm Turnbull, and now by Scott Morrison and Angus Taylor, was all hunky-dory, had a sound business plan, and it gave some graphic illustrations into how the project might work.

The idea is broadly this – to pump water uphill for storage when there was a lot of wind and solar generation around the country, and prices are low, and then let the water run down again and spin the generators when there is not so much wind and solar, prices are high and/or demand is strong.

Sounds fine. But exactly how much attention to detail has there been?

A quick glance of the graphs and illustrations reveal a remarkable development in the field of solar PV technology, at least in South Australia, where Snowy appears to assume that it is generated at night-time.

This graph below is from the Snowy Hydro “very high variable” renewable scenario, which would mean “Snowy 2.0 pumps all day with only a small reduction due to a small peak in VRE generation in the middle of the day.”

It goes on to say: “Snowy 2.0 stores surplus VRE generation to be saved over a whole day for later use when the market requires it most.”

Wonderful. But look closely at the graph, it has South Australia solar (the light green) generating at night, from around 12am to 8am, and again from around 6pm to 12am.

Could the boffins at Snowy got the colour confused with South Australia’s wind output?

Not likely, because that also shows South Australia wind generation also mostly at night. Can’t have confused it with NSW solar, because that is respecting the established norms of generating when the sun does shine, or Victoria solar, which is credited with little output, but at least it’s during the day.


The error was repeated in the graphs and illustrations accompanying the medium and low VRE output scenarios. We asked Snowy if this was an error, and we are guessing it is, but we didn’t hear back before publication.

Now, mistakes do happen. We know because we make enough of them here.

But maybe, given that it will cost $4.5 billion to build the project, and maybe another $2 billion to connect it to where it may be useful, it would be a good idea to reveal the full modelling and business case for Snowy 2.0, just to satisfy punters that there are benefits to taxpayers and consumers, and it’s not just a taxpayer-funded grab for market share.

Update: Snowy Hydro has since informed RenewEconomy that the graphs cited above were indeed an error, and the graphs have been corrected on the document on the website. We are also informed that the detailed modelling is also now available on the Snowy website. We will be looking in detail in coming days.


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