News for hackers. Stuff that matters.
Re:California exceeds 100% of energy demand with renewables ... by connicpu on Tuesday April 16, 2024 @03:11AM (#40049152)
Nuclear makes for great base generating capacity because it has an incredibly stable output, but that also means the line needs to be kept flat or tons of energy will be wasted.
Re:California exceeds 100% of energy demand with renewables ... by jillesvangurp on Tuesday April 16, 2024 @03:29AM (#40049264)
Nuclear is indeed very inflexible. You can't really turn it off easily or cheaply. The only time it goes down is for maintenance. Typically for extended periods of time when that happens.

However, battery is improving the capacity factor of renewables; especially solar by allowing two things:

- when there's too much of it, you can charge batteries with energy that would otherwise be curtailed/wasted. - when there's not enough solar, you can discharge batteries.

Both effects help dampen peaks and dips in renewable energy supply and demand. I.e. it helps flatten the curve similar to what you point out is the case with nuclear. The first effect is often over looked: we are actively curtailing renewable energy that we don't know what to do with. People talk about shortages but not about surpluses. And that's actually a lot of energy. It also leads to the fallacy in believing that having lots of EVs increases energy demand when actually it also allows for better utilization of surpluses. Which dampens the impact this has.

Grids are bottle-necked on a lack of cable capacity. We have overproduction of energy in one region and shortages in another. Northern and southern Germany are a good example where on a windy day in the north, the wind energy can't get to the industries in the south that need it. So, they fire up coal plants. The same is the case in the UK where getting wind energy from Scotland south is a problem.

Cables and batteries help improve utilization of renewables. The main thing that drives these things is cost. Nuclear is costly and very slow to deploy. Realistically, any nuclear we don't have right now, won't be there for at least a decade or two. And that's if we would be really diligent about getting to that right now, which of course we aren't.

In the time until then, we'll be deploying solar by the TW/year. Same with batteries. And wind is also growing rapidly. And of course laying some more cables is a lot less controversial than building new nuclear plants. There has been quite a bit of talk of upgrading existing cables with better ones to effectively double capacity. This is even less controversial since the permitting is a lot easier and faster. In short, we'll deploy orders of magnitude more of all this than nuclear, and a lot earlier too. So much that nuclear might turn out to be a rounding error.

Re:California exceeds 100% of energy demand with renewables ... by adev_ on Tuesday April 16, 2024 @05:01AM (#40049819)
Nuclear can scale up and down. It can do so from 20% to 100%, Reducing under 20% is problematic because it implies a reactor shutdown and restart.

20% is more than enough to modulate side by side with renewables.

The French Grid does that all the time intraday.

https://www.rte-france.com/eco2mix/la-production-delectricit...

Re:California exceeds 100% of energy demand with renewables ... by pbmonster on Tuesday April 16, 2024 @07:06AM (#40050581)
The French can only do that because they have so many reactors. If you ramp down a reactor, it poisons it's own fuel with radioisotopes and you can't safely ramp it back up - at least not quickly. You need to wait for the neutron poison to decay naturally, which takes days or even weeks, depending on how much you turned down the reactor.

The reason the French can get away with it is because they have to. If you have this much nuclear on your grid, you can't get around it, the reactors need to follow demand. The good news is that because they have so many reactors, they can have them take turns poisoning their fuel and still have enough time to slowly come back up again. So each night a different reactor ramps down and gets poisoned.

Also, French reactors can take the financial hit of decreasing output much better than American reactors. Nuclear has so small margins that if you tell the investors of a new nuclear plant in the US that their reactor will be required to ramp down a couple of times per month, the entire project turns into a huge financial loss just like that. They need to run at 100% all year, or lose billions.

Re:California exceeds 100% of energy demand with renewables ... by adev_ on Wednesday April 17, 2024 @05:42AM (#40062348)
> So each night a different reactor ramps down and gets poisoned.

They do it intra-day. You can currently follow that through their monitoring [^1]

> Nuclear has so small margins that if you tell the investors of a new nuclear plant in the US that their reactor will be required to ramp down a couple of times per month, the entire project turns into a huge financial loss just like tha

Nuclear reactors tends to be hugely profitable considering their lifetime (80y in USA) but requires an enormous CAPEX.

Like most infrastructure, any attempt to try to fund them entirely privately with investor seeking a 9% quick ROI is doomed to fail.

Hinkley Point is a very good example of that. It is estimated that the price per MWH would be more than halved if the project would have a funding by public bond instead of the current private investor deathtrap.

[^1]: https://energygraph.info/d/gr_6-QW4z/unit-availability?orgId...

Re:California exceeds 100% of energy demand with renewables ... by mschuster91 on Tuesday April 16, 2024 @05:18AM (#40049924)
That's only "economical" because the French taxpayers subsidize EDF with billions of euros both in direct subsidies [1] and in the form of price caps [2].

[1] https://www.theguardian.com/business/2022/feb/18/french-gove...

[2] https://www.bloomberg.com/news/articles/2023-11-14/france-an...

Re:California exceeds 100% of energy demand with renewables ... by adev_ on Wednesday April 17, 2024 @05:18AM (#40062236)
That is deeply incorrect.

EDF as hugely profitable and brought back billions to its main stock holder (the French state) for multiple decades.

The recent debt crisis has mainly two causes:

- The state has used EDF to shield consumers against the 2022-2023 energy price increases. EDF has taken the losses directly for the state.

- The results of terrible energy policies the last decades (attempt to reduce nuclear at 50% and mainly the infamous ARENH).

What happened is pretty typical of when you have a state is directly managing a private actor: Incompetent politicians swiping their foots on the company to satisfy their own demagogy.

Re:California exceeds 100% of energy demand with renewables ... by soco on Tuesday April 16, 2024 @05:27AM (#40049983)
The way I understand it, there's a lot of talk about more solar and more wind and more whatever, but much less talk about more cabling between regions. Or maybe it's happening just doesn't make the headlines? Because even today we could scrap a few more percents by simply redistributing better the energy where it's needed...
Re:California exceeds 100% of energy demand with renewables ... by toast0 on Tuesday April 16, 2024 @11:57AM (#40053668)
Increasing grid connectivity is certainly happening, but it's not very exciting. You see news about new large undersea connections. There's news from time to time about the Tres Amigos interconnection facility between the US grids in the east, west, and Texas (mostly delays, unfortunately). News here and there about better connectivity between north and south england. Local news about local projects (my area is wiring some leaf substations into a ring; very exciting for me, not much for anyone else; although the why is to provide reliability to a charge an electric ferry that carries 200 cars, so maybe a little exciting?).

A lot of times connectivity impacts site selection of projects. A wind farm needs to have good wind, reasonable neighbors, and access to loads. There's articles about not being able to build more wind in northern england because there's not enough transmission infra to get the power where it needs to be.

Re:California exceeds 100% of energy demand with renewables ... by akira2501 on Tuesday April 16, 2024 @03:30AM (#40049275)
> or tons of energy will be wasted

How do you mean?

Nuclear power plants can scale with demand. They're primarily steam generators and those feed turbines. You have many mechanisms you can use to control total power output in these systems.

In the sense that you're wasting fuel lifetime, to a certain extent, but I imagine that also varies with the level of reactivity currently allowed in the vessel by the control rods.

Re:California exceeds 100% of energy demand with renewables ... by connicpu on Tuesday April 16, 2024 @11:24AM (#40053204)
Other commenters also pointed it out, but ramping down a nuclear reactor is not an easily reversed process. After a ramp down the fuel needs a certain amount of time before it can be ramped back up again. The output can be modulated, but it's a process that must be performed over a long period of time.
Re:California exceeds 100% of energy demand with renewables ... by krasin on Tuesday April 16, 2024 @03:14AM (#40049167)
> or tons of energy will be wasted.

There are good potential industrial loads for that intermittent extra energy (nuclear or solar): desalination, CO2->methane, air->ammonia, etc.

Re:California exceeds 100% of energy demand with renewables ... by dvh on Tuesday April 16, 2024 @03:20AM (#40049202)
Counterpoint: Zaporozhye