matthewtoad43

@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.

@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.

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Sadly it is much easier to build an extra 10GW of peak gas plant than it is to build an extra 10GW of nuclear plant. The tradeoff is of course that the gas plant is inefficient and therefore extremely expensive per unit generated (but not used very often). Not to mention destroying the planet.

But that is how we largely managed it in the past.

In the future, and even the present, fortunately we have better options.

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis The fossil fuel grid we had 20 years ago relied on gas peak plants and hydro for peaks.

Nowadays we have diesel farms (eeek!), and increasingly (thankfully!) batteries.

The actual UK grid today is only 45% fossil fuel (and some nations and states are better than that). We also have more interconnectors than we had in the past.

UK nuclear has generally been used as baseload for many decades.

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis What do you mean it doesn't scale linearly?

If you need to over-build by 3x, then it costs £150/MWh.

If you need to use £170/MWh storage for 10% of demand (plausible for hydrogen), you still get a very reasonable figure.

There's no obvious non-linearity here. Switching off renewables is trivial, unlike thermal plant.

@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.

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Nuclear does not avoid the need for short-term storage to cover the peaks, unless you can build vast amounts of it (equal to peak).

Nuclear *does* avoid the need for long-term storage, if you can build enough of it (equal to average).

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Farm scale solar, onshore and offshore (non-floating) wind cost approximately £50 per MWh in the last CfD auction. That's half the CFD agreed for Hinkley C.

Mature renewables are already cheaper than nuclear. By a factor of two, compared to first-of-a-kind over-budget new nuclear.

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Can you name *one* nuclear project in the last 20 years in Europe that wasn't severely over-budget and severely delayed?

It's not just the UK. Every third gen PWR has taken way longer than expected.

The public rightly insist on the safest designs possible. And those at least have been tried once (generally only once!). However, they take a long time.

@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis That graph includes some huge deployments of wind, and today, it's a mature, cheap technology (though still improving). Same with solar.

On the timescale on which the historic installs occurred, that was not the case: nuclear and hydro were the only mature options.

@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.

@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.