The other thing to remember; is that this is not a generation asset; it a demand shifting system. Very useful, but it doesn’t bring new capacity online, where as the same money spent on solar would bring significant new capacity online.

I may have misunderstood, but isn't this $16B project to build a brand new dam and brand new hydro generation capacity? It sounds like this hydro would add 8TWh of annual generation capacity:

If run for approximately six months, the huge project would produce around 4 terawatt hours of power – more than all of the country’s current hydro schemes put together.

The pumping part is the demand shift, but the project appears to add significant generation capacity even without the pumping part.

[–] absGeekNZ@lemmy.nz 1 points 4 days ago (1 children)

Generation would occur through underground turbines then, at off-peak times, water would be pumped from Te Mata-Au/Clutha River, via a lower reservoir, back up to refill the depleted lake.

The project would generate up to 1000 megawatts of electricity. If run for approximately six months, the huge project would produce around 4 terawatt hours of power – more than all of the country’s current hydro schemes put together.

The way I read this is that the bulk of the power will be from the pumped part of the scheme; not new generation. Some will come from the 'natural' filling of the lake. But the story doesn't say what % that would be; I have to assume that it is minor, otherwise it would have been highlighted as a major part of the justification for the project.

Also their math is shit; 4TWh = 1000MW running for 4000 hrs; which is just under 6 months (4320hrs); so how much time are they pumping for...only 320hrs out of 6 months....or ~8% of the time.

This whole project is based on unicorn fart justifications. This project will not run continuously; it will be used to buy power low and sell high. At best it will stabilise the pricing to reduce the big swings.

You know what works well in a dry year....solar.

[–] Dave@lemmy.nz 2 points 4 days ago (1 children)

I just assumed that the article focuses on the pumped part because it's new and exciting. They also discuss that this opens up opportunities for wind and solar, any thoughts on that? It kind of implies the wind and solar projects couldn't happen without it.

“Being down in Central Otago, this project will unlock a great deal of wind and solar development in Southland. There’s a lot of projects in Southland that need support for the intermittency of wind and solar.”

If the project goes ahead, it will provide firming for “several thousand megawatts of wind”, making investment in renewables more viable for generators, he says. Onslow investors “could well be part of that”.

[–] absGeekNZ@lemmy.nz 2 points 4 days ago

Yes....

The idea of the 'infinite' grid; is that all points are 'equivalent' in the system. Local generation is no more advantageous than remote generation.

This is of course not how reality works. But it isn't too far off, when you consider how efficient the HT system is at transferring energy.

Local generation mainly provides resilience for when there is a natural disaster. This is obviously extremely important; but it is not a justification in and of itself. Also what does 'provide firming' actually mean when we consider the context.

If there is several thousand megawatts of wind planned and economically viable; local storage shouldn't effect that. A MW of power produced in Southland may be consumed locally; or it may be consumed in Auckland; electrically from the point of view of the grid; these are the same place. Power will flow to where it is easiest; we direct the flow using various methods, but it is physical laws that drive the flow.

If we add 1GW of solar in Northland; it will be better than 1GW in Southland, simply because the Northland system will be smaller to get the same output.

If Southland has great wind resource; that is great and it should be developed; the whole country will benefit.