@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis But the fundamental thing for me is I won't wait for new nuclear.
We need to cut carbon emissions *NOW*. That might mean starting some new nuclear power projects. But both renewables and short term storage are being installed today, cheaply, and while there are some obstacles to this (e.g. grid access), balancing is not the main problem.
We can't use nuclear as an excuse any more than we can carbon capture.
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis It is well worth reading the original Australian model.
That has 60% wind and 45% solar, with hours of storage, including some hydro, reaching 98%, using real world data (and scaling the output of existing plant). Going from 105% capacity to 170% eliminates the problem entirely - assuming no freak weather events not included in his ~ 1 year trace. Equally you could solve it with long-term storage. Long-term storage doesn't have to be cheap or efficient per kWh; it's the capital cost, the ecological cost (e.g. hydrogen leaks), and whether it's feasible at all, that's the real question.
If you don't have nuclear equal to your *PEAK* demand, which looks unlikely on any reasonable timescale, then either you need quite a bit of storage, or you need to accept there will occasionally be power cuts for non-essential users.
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Interconnectors make the "long term no wind in winter" scenario much less likely, though obviously this varies depending on the country; there's less opportunity for it in Australia, but on the other hand it's just much bigger - "long range" may be within the country.
As I understand it the Australian study was based on real world data.
But let's say you're right. After all the study accepted that 2% of the time it's not sufficient. You have a few options for that last 2%. One is more nuclear - not necessarily 100% nuclear, or even 40% nuclear, but enough to prevent any freak weather events from causing serious harm. Another is hydrogen - an immature technology that is nonetheless 50+ years old.
There was a European study ... I think I lost it on X though. That specifically made the case for hours not days. But to achieve that you have to over-build.
Really one of the biggest arguments for nuclear is that over-building renewables makes a minor problem with rare earths into something much more serious.
Most likely we need either some nuclear or some long-term storage. Long term storage means immature but clearly technically feasible technologies: hydrogen or iron-air, maybe a few other candidates. Against that you have the fact that with the exception of France in the 1980s, building large amounts of nuclear power quickly has almost never happened.
Nuclear just takes too long. So use it for what it is - a modest amount of baseload power at roughly twice the cost of renewables.
Let me see if I can find some of the sources ... I already posted the study on Australia.
Here's a Scottish one, they concluded that over-building renewables is feasible. Also arguing for some more hydro. Unfortunately hydro is generally considerably dirtier than nuclear.
http://re100.scienceontheweb.net/
https://scottishscientist.wordpress.com/2017/07/14/wind-storage-and-back-up-system-designer/
Here's the National Grid's view; IIRC they are skeptical about the claim of 24GW of nuclear by 2050, but their models say it won't be enough on its own anyway and bet on hydrogen.
https://www.nationalgrideso.com/document/263951/download
Here are some of the numerous academic-ish sources, probably out of date. As I said, system models often assume there is infinite lithium, so doubtful IMHO.
https://web.stanford.edu/group/efmh/jacobson/Articles/I/145Country/22-145Countries.pdf
https://twitter.com/AukeHoekstra/status/1557466581185224704
https://www.helsinkitimes.fi/themes/themes/science-and-technology/22012-researchers-agree-the-world-can-reach-a-100-renewable-energy-system-by-or-before-2050.html#.YvPUxCrrWdI.twitter
https://ieeexplore.ieee.org/document/9837910
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis What you say about "40% volatiles" is a myth.
Currently we (UK) always run at least ~3GW of fossil fuels, as well as a surprisingly variable amount of nuclear, because of the inertia problem. That will be solved by 2025.
https://www.nationalgrideso.com/electricity-explained/how-do-we-balance-grid/what-inertia
Britain is up to 36% renewables *on average* over the last year, and still building fairly quickly. Plenty of countries have much higher proportions of renewables. But they also have other ways of dealing with it, e.g. Denmark's trick was always much more energy trading.
Iceland is 86%, Norway is 76%. It can be done, though these figures are inflated by geothermal and hydro, which may not be viable for the UK. Sweden is 63%, but that includes a fair bit of biofuels. California is already up to 59%.
Intermittency is a problem, there are lots of ways to manage it. Nuclear is one of several options.
The amount of lithium batteries needed to reach 100% is probably ecologically unreasonable, although several academic studies do talk about this. So we probably do need some nuclear, unless iron-air batteries or hydrogen pan out rapidly. Nonetheless, the idea that there's a ceiling of 40% is way out of date.
https://www.euronews.com/green/2023/01/20/which-european-countries-use-the-most-renewable-energy
https://www.govtech.com/smart-cities/california-hits-new-record-for-renewable-energy-generation
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis As I already mentioned, California has 2.5GW of batteries today. And credible half hourly models suggest that you only need hours of storage to get up to approximately 98%.
There are lots of ways to solve intermittency. Nuclear is one strategy that potentially works, but still needs short term storage - modern designs can vary load, but not quickly.
3x renewables plus a few hours storage is likely fine. So is a lot of nuclear. Hydrogen or iron-air *might* make the whole thing much cheaper, but indeed are immature technologies. More interconnectors are mature technology that always makes it easier, but are not enough on their own; dynamic demand is helpful and semi-proven.
But building "too much" renewables while we wait for nuclear is fine. Because most likely that nuclear will never be delivered. At least not in the UK. And as I understand it the supply chains don't really overlap. But above all because *it's the total carbon emitted that matters*. We're on a deadline.
I see no obvious reason to expect that the UK can build large amounts of nuclear quickly, even if there was the political will to do so. Successive governments have tried and failed. On recent progress, by 2050, if we're lucky, we might have 3 more 3GW plants running, which is nowhere near current demand, let alone future demand with electrification.
Even if the government meets its own target of 24GW by 2050, which seems extraordinarily unlikely given the slow progress so far, that will be a lot less than the total peak demand given electrification. So you still need storage.
So I'm not going to campaign to stop building renewables on the basis that one day we *might* build more nuclear.
Having too much renewables is *NOT* a problem, especially when compared to nuclear that will probably never materialise. Worst case, switching off wind and solar farms is much easier than switching off nuclear reactors. Best case, we can export that energy, use it for intermittent energy intensive industrial processes, or store it.
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Also on the timescale: Labour have officially said they would reach 100% clean electricity by 2030, starting in 2025. That's generally seen as challenging, but it may well be possible (albeit at a high cost in lithium and rare earths). There's no way it can be done with nuclear. In any case we need to move fast; most of the rest of the transition depends on clean electricity. My main objection to nuclear is simply that it will take another 20 years to get maybe 3 more reactors if we're very lucky.
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis So no, nuclear is not the only proven option by a long way. Nor is it a feasible option on its own IMHO. And new designs increase risk and time. Building multiple reactors to the same design saves time and money, of course.
Nuclear is an option. It probably isn't enough on its own any more than any of the other options are. There is absolutely no reason to stop building renewables, and slowly scaling up various storage options, today.
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Short term storage already exists. So does wind, solar, at considerable (though inadequate) scale, and cheap (bottlenecked mainly by grid connection). Dynamic demand exists to some degree and so do interconnectors.
Lithium batteries exist at reasonable scale in other countries, notably 2.5GW on California's grid. There are active trials of V2G but IMHO reasons to doubt how big a contribution it will be. Reusing EV batteries as grid storage exists at a small scale.
Nuclear power plants take forever to build, in recent experience in the UK. Even National Grid doesn't believe the government's promised 24GW of nuclear will be done for 2050.
There are uncertainties whichever way you go. So we need several strategies. However, it's worth pursuing iron-air batteries and possibly hydrogen as well as nuclear. But arguably they are only needed for the last few percent anyway. And I will *not* accept any attempt to slow down installation of renewables in favour of nuclear.
Decarbonisation, in terms of electricity in the UK, has been achieved through both nuclear and renewables. Fossil fuels are down to 40% of total units generated.
Figures for the last year in the UK:
Source GW Percent
Coal 0.32 1.1
Gas 11.30 38.3
Solar 1.38 4.7
Wind 8.82 29.9
Hydroelectric 0.34 1.2
Nuclear 4.44 15.0
Biomass 1.49 5.0
Unfortunately nuclear plants are closing rather rapidly, and it will be some time before replacements are online.
PS IIRC there are plausible sources saying that you only need renewables equal to ~3x plus short term storage. Both aspects of this are technically feasible and proven today. But obviously it means more rare earths etc. More nuclear, or more long term storage, or more interconnectors etc, reduce the cost.
@MattMastodon @BrianSmith950 @Ardubal @Pampa @AlexisFR @Wirrvogel @Sodis What would the cost be of fast bidirectional charging points for all those cars though? Both at office and at home? Do you need them to be fast charging, or is V2G at 7.5kW realistic/useful?
You'd be lucky to get 30%. IMHO the resource is somewhat limited depending on how much you put into charging infrastructure.
@MattMastodon @BrianSmith950 @Ardubal @Pampa @AlexisFR @Wirrvogel @Sodis Also, smart tariffs for EV charging (dependent on when there is most renewable energy) already exist, at least two companies doing them. That's not V2G though.
@MattMastodon @BrianSmith950 @Ardubal @Pampa @AlexisFR @Wirrvogel @Sodis IMHO reusing ex-EV batteries as grid storage may be more important in the medium term though.
@Ardubal @MattMastodon @BrianSmith950 @Pampa @AlexisFR @Wirrvogel @Sodis Second generation reactor designs that would never be built today. Vulnerable to climate change because they were built on rivers. Also, Britain is not France.
Right now, renewables essentially build themselves. They do not require a state subsidy - the "contract for difference" level is set at roughly the wholesale price of electricity.
Whereas no nuclear is ever built without massive state involvement.
Not that that's bad. We need more state intervention in e.g. insulation. But it's slow. We can't afford to stop installing renewables now on the basis of a few reactors that may well be cancelled by a future government.