Lemdro.id

1 point

1 year ago

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Sure, 80s French reactors can. As I understand it, modern PWRs can vary load but relatively slowly.

And in any case it is highly unlikely that we will be able to match *peak* demand with nuclear capacity.

You at least need significant intra-day storage.

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1 point

1 year ago

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis I do not understand your diagrams - which curve is the EPR on?

Realistically we’ll have to build more EPRs. There isn’t time to try more designs out.

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@matthewtoad43 @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis

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Svante@mastodon.xyz

0 points

1 year ago

Nuclear is faster at load following than everything but pumped hydro and (very dirty) gas peakers. It was even a design requirement for the german Konvoi type in the 70s and 80s.

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1 point

1 year ago

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Do you have figures for a modern PWR? Any modern PWR, and specifically EPR1000, since we’re likely stuck with that?

In any case, you still need storage, because you won’t be able to build capacity to peak demand.

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@matthewtoad43 @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis

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Svante@mastodon.xyz

0 points

1 year ago

https://en.wikipedia.org/wiki/Load-following_power_plant#Nuclear_power_plants

For a grid of 100 GW peak demand, you either need

- 100 GW nuclear plants, or

- 100 GW storage output, plus (100 GW × storage loss factor) storage input (volatiles or whatever), plus additional transmission capabilities, or

- a combination of 60% nuclear plus, say 10% hydro, plus 30% volatiles

I’d say some variation on the last looks most plausible to me.

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1 point

1 year ago

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Well if we’re ruling out long term storage (iron-air batteries and hydrogen), maybe 30-40% nuclear, 80% renewables (intentionally over 100%), and a fair bit of lithium storage?

Ultimately this is determined by how much we can build of each technology by the deadline (which ideally is 2030 or 2035). If we can scale up iron-air fast, that’d be great, but there’s a lot of uncertainty there. But this also applies to nuclear: How much new nuclear we can build by 2035 is probably quite limited. Whether hydrogen can be significant on that timescale, and whether leaks can be managed, is another big question.

It’s worth trying all the plausible technologies (i.e. other than biofuels and fossil+CCS).

PS “volatiles” *already* make up over 30% of the UK’s generated kWh. 😀 So I expect a higher figure.

IMHO the only thing that matters more than the ecological impact of the transition is the *speed* of the transition. Because that determines total carbon emitted. And it determines the carbon intensity of the rest of the transition.

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@matthewtoad43 @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis

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Svante@mastodon.xyz

0 points

1 year ago

Yes, but I’d like to add that we need to think about lifetimes.

Let’s imagine having built all we need in 30 years, through sometimes extreme efforts.

Current solar panels, wind turbines, and batteries have a lifetime of (a bit generously) 30 years. So we’d have to immediately start again with the entire effort just to keep it up. I’m worrying that this might not be … sustainable.

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1 point

1 year ago

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Fortunately we will have time to work on that. There is plenty of existing renewable plant coming to the end of its service life for us to work on recycling.

Also, hopefully longer term we move towards more rooftop solar rather than farm scale, though of course the amount of land used by solar is insignificant. Short term, farm scale is easy to install; long term, rooftop could be a requirement of construction.

Just as important, once we reach 95%+ renewable electricity, the ecological cost of building new stuff, whether recycled or not, drops dramatically.

Do we want to move towards more nuclear in the long run? Maybe so. On the other hand, the cost of renewables will continue to come down, and it’s reasonable to expect the same is true of storage.

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