I wouldn’t call it just useful. As far as I understand it’s the best realistic shot we’ve got.
To decarbonise transport storage needs to massively increase. There are 30 million cars in the UK, that alone is 3TWh of storage, which isn't far off a day's total energy use. If we can make 3TWh then it's reasonable that we can make 2 or 3 times that much.
It won't be financially viable to operate a nuclear plant for the few days a year that the wind and solar and storage and imports can't cover the use, better to simply increase storage and production a bit more.
Edit: I should note that one proposal I’ve seen to mitigate some of this is to improve long distance transmission, since it’s never cloudy everywhere, and taken to an extreme, you could, for example, put lots of solar in the Sahara to power the UK, or even send power from the hemisphere in summer to the hemisphere in winter. But then, besides the huge capital costs for building out transmission infra, you run into energy independence issues/trust issues between governments. But maybe within large political blocs like the EU, Italy/Southern Spain could sell solar power to the more northern European countries, with less risk.
And of course a ton of short term storage.
And then you build a bunch of cheap, inefficient gas peaker plants for the two weeks a year where neither are enough.
At the moment it looks like that will be a lot cheaper than nuclear. But if nuclear gets cheaper, that’s also a great option!
In New England we pay upwards of 14 cents per kwh or higher. My understanding is that this would buy a substantial overbuilt, it's likely that energy prices upwards of 30 cents per kwh would be politically viable provided there were guardrails to keep heat/hot water cheap.
Pumped hydro storage was better, if you have the water resources and elevation change nearby. Lots of places don’t.
The magazines will be full at times, but when they are not, it should be possible to just pump the water back up again and thereby store excess wind and solar power.
I live in Sweden, and yeah, flooding large amounts of new land will be impossible by now.
The indigenous (Sami) people will say no and file lawsuits. And rightly so, they just didn't had that option 100 years ago.
But there is an abundance of existing magazines that can be used this way. They are full around November but after that they start to drain.
Because it’s nowhere near effective enough.
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I suggest watching a few videos by particle physicist Sabine Hossenfelder to educate themselves on this topic
