I'm no expert, but is there any storage system that is practical that can store the amount of energy we'd need to have most (all) electricity come from renewables?
In the meantime, load sharing is used to distribute power across a power grid for cases where one area has more power and another area needs power. For instance, wind may die out in one area but over larger areas there are usually still areas with wind. It’s harder with solar, of course.
Not necessarily enough wind to be useful. If you look at graphs of wind turbine output across entire large power grids, you see 4:1 variations in a day over the PJM and CAISO regions.
That's irrelevant to this blackout, anyway. This blackout occurred during a period when supply far exceeded demand.
It's quite possible -- over the previous 30 years we've never had an hour where there was no wind & sun anywhere in Europe. So we could theoretically solve it without storage, but that would require an insane amount of overbuild and interconnect. Imagine supplying all of Europe's electricity needs with just wind power from the south shore of Ireland.
Adding a few days worth of storage reduces the interconnect & overbuild needs dramatically, putting 99.99% carbon free within the realm of the possible.
Sure... but my expectation is that that 90% solution would include an unreasonable amount of storage (assuming you want most/all renewables). I guess was my point.
> It's quite possible -- over the previous 30 years we've never had an hour where there was no wind & sun anywhere in Europe.
But "some" wind or sun is not enough to support the whole grid.
In that scenario 90% is very easy to hit. A couple of hours worth of storage, maybe.
> But "some" wind or sun is not enough to support the whole grid.
The less there is, the more you have to over build to compensate. Doesn't make it impossible.
It’s highly unlikely to be abnormally cloudy/calm over the whole of Europe, for example, so Europe’s large grid (https://en.wikipedia.org/wiki/Continental_Europe_Synchronous...) can be used to move electricity from where there’s excess energy from solar or wind to where there’s a deficit.
That requires large capacity connections, though that aren’t everywhere yet.I understand electricity was restored in the south of France much more rapidly last week than in Spain and Portugal because it’s much better connected to the rest of Europe.
This is a political problem, having Mitteleuropa depend on power from Putin is apparently OK, but on lazy southerners is verboten. Hopefully this blackout changes that (but I'm not holding my breath).
If you look at the European road and rail networks, you’ll find France and Spain aren’t well-connected, either.
I have no idea if it’s feasible to fill longer-term gaps during extended cloudy/windless days and nights using that alone, though. Other than that, there are already large-scale battery plants deployed in some cities.
Another approach is to control the demand side: When air conditioning or heating with electricity, minutes usually don’t matter, and dropping/providing extra load at very short notice should be feasible in a smart grid.
So the more you use them, the more energy you need in the first place, so you try not to use them too much. And the worst thing for a capital intensive business is to not get used much. Even with the arbitrage advantage, it takes a long time to pay it off. The grid may pay a "retainer" to sweeten the deal but you can't just build more and expect them all to get that benefit.
It's similar to the problem that "use excess energy to electrolyse water into hydrogen" has: no-one running a multi-billion electrolyser really wants to run it a few hours a day only when the grid is oversupplied. And in top of that, risk being cut off at the knees decades before breakeven if someone comes along with a cheaper/more profitable way to deal with the oversupply.
https://en.wikipedia.org/wiki/Iron_redox_flow_battery
Its commercially available right now as well.
Its not as efficient as lithium or as energy dense, but that doesnt matter if you're putting them in wind/solar farms.