Comment by pydry
3 years ago
>as far as I know, there exists no proven, cheap, scalable technology to store power at grid scale at all
It's called pumped storage.
We dont need as much storage as people think. Solar and wind anti correlate and a vast amount of demand can be time shifted.
The anticorrelation is mostly on longer timescales. Winter vs summer for example. On a daily or hourly basis the anti correlation is pretty much non existent and it's on these timescales that you would time shift demand. A quite common occurence in Europe is that large parts of Europe during winter have almost non existent air pressure differences for days or weeks on end. During these times neither wind nor solar is very helpful and other solutions are needed, not all European countries have the pumped storage capacity for that. LNG to the rescue I suppose, now that Russia is limiting supply.
I was wondering if someone was going mention that. Pumped hydro is great, but it's not scalable. You need favorable geography to make it economical at all, and in the end it doesn't store enough energy to do more than smooth over transient grid fluctuations lasting a few hours. The UK is, relatively speaking, quite well provisioned with pumped hydro - its largest storage facility is Dinorwig in North Wales, which is built into a mountain with very favorable geometry - it has nearly 6 times as much capacity as the next biggest station. It can store enough energy to run the entire UK for... about 16 minutes. That's not going to do the trick if the grid runs entirely off wind and solar and you have a dark, calm day, let alone the weeks at a time that weather can be unfavorable. And there isn't anywhere to put another hundred Dinorwigs, never mind the budget.
It's because of this that there's a lot of talk about wild ideas like pressurizing abandoned mines and so on - there are a lot of mines around. But then we're back to the "proven technology" sticking point.
The suitable geography is considerably less rare than the nuclear and carbon industries jointly like to pretend. This has been confirmed by multiple studies (I have posted them at least 3 times before because this talking point is sadly rather common).
Nowhere is currently "well" provisioned for pumped hydro given a solar and wind grid coz while they existed for over a hundred years they have never had to store that much energy. Newer, larger ones are being built around the world. Australia will be well provisioned soon.
Go back in time 10 years when solar and wind first became economic and people made similar comments about how little of it there was (1% of total power!), ignoring the unit economics completely. We are at that exact same inflexion point with pumped hydro.
The largest pumped hydro facility in the world is Fengning in China, at 40GWh, and the second largest is Bath County in Virginia, at 24 GWh. Dinorwig's 9GWh is really not too shabby. Even Fengning would only power the UK for just over an hour. This is simply not the same order of magnitude for the storage you'd need to make it through a gray UK winter on renewable energy alone.
What's the longest period without wind and sun you're willing to provision for before you give up and tell the population they'll have to do without electricity for a bit? A day, a week, a month? Numerically, how much storage would that actually need? How many stations, how big? You'd need over a hundred Fengnings to power the UK for a week. Where would they go? I'm all for renewables + storage but you can't handwave these questions as FUD, it's a serious problem.
I suspect that if we committed to categorically eliminating fossil fuels, including peaker plants, the first time the lights went out because the weather was bad you'd have people clamoring to build nuclear power plants. Statistically, it'll happen at some point no matter how much storage you provision.
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