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Comment by nosbo | Hacker News Reader

Or just overbuild your generation sources?

How is overbuilding going to help when the source of the power itself is intermittent? The sun regularly sets and the wind has this unfortunate habit of not blowing. Or, oddly enough, blowing too much.

If we hope to go 100% renewable, storage is a key piece of that puzzle.

It wont help much but it was the actul solution when the main source of electricity was fossil fuels because you could stockpile the fossil fuel

Nuclear also has this problem because it cannot be easily tuned down during low demand periods.

Much of the pumped hydro that exists today was built to handle excess nuclear.

Nuclear's electrical output can indeed be turned down, by over-cooling the steam in the turbines. The reactor is putting out the same power, but less electricity is generated since you're deliberately increasing waste heat. This is not efficient so it's rarely done.

Furthermore, too much energy is a far easier problem to solve than too little energy. People can desalinate water, or do any other energy intensive things.

Technically yes if you have an entire fleet to both spread the load following across and their manage their fuel cycles since they get less flexible the further into a fuel cycle a reactor is.

Economically? Load following with nuclear power means an even worse business case than running at 100% 24/7. And nuclear power is already a laughably bad business case when running at 100%.

The fuel is burned at the same rate using this method of modulating output. Thermal output from the reactor is the same. Electrical output is reduced because heat is deliberately wasted.

Nuclear can handle variable loads just fine, if reactors are designed with load-following in mind. France does that, for example.

Technically yes if you have an entire fleet to both spread the load following across and their manage their fuel cycles since they get less flexible the further into a fuel cycle a reactor is.

Economically? Load following with nuclear power means an even worse business case than running at 100% 24/7. And nuclear power is already a laughably bad business case when running at 100%.

You don't need to change fuel cycles to reduce the output of a nuclear plant. You can accomplish it by more aggressively cooling the water in the steam turbines, effectively wasting heat (and thus generating less power).

Nuclear is a bad business case compared to a fossil fuel grid. Solar and wind backed by fossil fuels are a better business choice, too. But when it comes to a fossil-fuel free grid, it's the only viable option if you don't have a big source of hydropower nearby. Batteries can't deliver the required storage capacity. Remember, the world uses 60,000 GWh of electricity per day. And as transportation and industrial uses of fossil fuels are electrified, that'll increase.

Batteries and hydro are not the only storage options.

What are the other storage options? Besides batteries and hydroelectric, there's only prototype technologies that haven't seen any significant deployment at scale. Compressed air, hydrogen, and power to gas have been tried but no at anywhere near grid scales.

Five years ago batteries weren’t anywhere near grid scale either. Arguably they still aren’t. That doesn’t mean we should not consider them when talking snot the grid in 2040.

Sure. But we also shouldn't assume they will be successful at grid-scale either. Planning a grid assuming that some future storage technology will be a silver bullet that solves grid storage is a massive gamble.

Hydroelectric storage is the only grid-scale energy storage system available to us, and it's geographically dependent. And the places that are suitable for hydroelectric storage usually don't need it because they can just generate electricity via hydropower anyway. Until your hypothetical breakthrough in power-to-gas or giant flywheels actually happens, this is the state of grid storage.

It's not such a massive gamble if you can just keep relying on natural gas peaker plants in case storage is somehow unsolvable, which seems quite unlikely given that we have a dozen completely different technologies for storage in the pipeline.

Notably it also runs the reactors much harder, which has led to situations like France needing to shut all nuclear plants at once for maintenance.

“Oh no we have too much power, what are we going to do with it” is a much better problem to have than “the sun and wind are going down at the same time and we don’t have enough power, what are we going to do about it”.

It means the nuclear power plants shut down and then start losing money hand over fist, eventually closing.

Don’t piss on my leg and tell me it’s raining. Most of the costs and all of the shutdowns in nuclear power are primarily motivated by anti-nuclear activism. What you’re describing is a policy choice, not an essential reality.

If it costs you money to generate power at a time you cannot sell it, that is losing money. Wind and solar are unique in that they have low marginal costs, whereas a nuclear plant requires more staffing and fuel burn.

I don't understand why you're coming about this problem from a "100% nuclear" situation. That's not the case for the world, and likely never will be the case. But heck, let's assume all you've got to work with is nuclear.

You have a baseload. That's basically the minimum load that always exists. You don't have to worry about selling the power, it's already sold. And then you have peak. Both of these are time / weather dependent but we're still quite able to plan days, if not weeks and months, in advance for what those two values will be. As an example, let's get back to the original topic of the article.

If you're Google and you have a particular datacenter at a location, you know what that baseload is. You know what the peak is. It's a pretty simple calculation to figure out what is most cost-effective here. It's probably even easier for you than the local power company, as base and peak loads likely don't fluctuate much for you outside of HVAC keeping up with weather. It might be to use nuclear for just base load and use the local grid for the rest. It might be to over-produce occasionally because that's still cheaper than buying from the local system operator. Hell, you can probably sell any access, but that's more of a problem than most people think.

But the point is nuclear is king when it comes to baseload power supply. And a datacenter, which consumes a lot of power consistently, is almost entirely baseload.

Also, if you're serious about the problem of "our nuclear power plants are producing more power than we need and we can't turn them off because then we'll have a power shortage", there are applications to dump "bonus" energy into. You'd run into the same problem with renewables too; the difference is that with nuclear, you can avoid the "not enough energy" problem.

If you're not in Texas, there's such a thing as paying to keep capacity available, and then you don't lose money.

And power plants having individual finances in the first place is a policy choice, not a law of nature.

We have a version of that in Texas, too. There are some commercial cryptocurrency mining operations that pay for a certain level of power capacity, and if the grid is running low on power, the grid just buys the capacity back from them and they stop mining for awhile.

If you find cryptocurrency mining objectionable for some reason, you could apply the same basic principle to things like aluminum refining or desalination.

That's still only paying when the capacity is needed. It doesn't do a good job of incentivizing power sources/releases that are needed very rarely.

Simulation studies have covered this. It addresses it by providing more power when there is less sunlight and less wind.

Overbuilding doesn't make solar generate power at night. Days with minimal wind can see 10% average wind speeds or less.

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