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Comment by the_economist | Hacker News Reader

Renewables don't provide constant power without city-scale energy storage, which doesn't exist (yet) at any reasonable price point. Solar for example won't provide power after sunset or on cloudy days.

Because you can't rely on renewables to provide power throughout every day/year, you need to have natural gas/coal/nuclear available. Those have very high fixed costs (other than natural gas), but very low marginal costs, so once you have built them it is cheaper to just use them than to build additional renewable power infrastructure.

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That is exactly nuclear energy comes in. It is impossible to actually run a grid off a renewable (esp. Solar) energy power-plant in any stable manner.

Nuclear energy serves the purpose of acting as the filler for the delta between the peak and trough.

>It is impossible to actually run a grid off a renewable (esp. Solar) energy power-plant in any stable manner.

I agreed with that before Tesla's Big Battery experiment - and that leveraged established tech. I can't wait to see how sodium or one of the other, in-dev materials eventually supplant lithium, on a massive scale.

> I agreed with that before Tesla's Big Battery

Tesla's battery isn't really grid-scale energy storage of the kind you'd need to do 100% renewables. It's more for smoothing out fluctuations in the grid than for filling in for intermittent sources when conditions are poor.

If the gamble on renewables works out, it will be because of geological hydrogen energy storage. That's the only way to get country-days worth of storage at a price that's actually feasible (if it works in practise like it does on paper).

> It is impossible to actually run a grid off a renewable

It is equally impossible to run a grid from only nuclear power. These assets can't "load follow" which is why in the US the 1970s build-out of nuclear power was contemporaneous with the build-out of pumped hydro storage.

Europe already runs load following plants for a long time now. Article from 2011.

https://www.oecd-nea.org/nea-news/2011/29-2/nea-news-29-2-lo...

If the topic here is still "not R-wing enough", Nuclear power is something that Republicans generally agree with increasing more so than Democrats [1].

It's still lower than I'd prefer, further nuclear power research seems by far the best way to truly go off fossil fuels long term (even with the improvements in batteries, we are several orders of magnitude away from it actually being realistic to build them for power grid scale energy storing).

New reactor designs can go 72 hours [2] without any human interaction, which avoids much of the natural disaster concerns, such as requiring generators for cooling, which is what caused the major problems in Fukushima.

[1] https://www.vox.com/energy-and-environment/2019/4/23/1850729...

[2] https://en.wikipedia.org/wiki/AP1000

>Nuclear energy serves the purpose of acting as the filler for the delta between the peak and trough.

No. Just. No.

It's incredibly stupid and inefficient to use nuclear as a peak power plant. Due to the huge CAPEX reasonable power system should use nuclear for base load and maximize capacity factor as much as possible.

Yes, there are experiments on maneuvering nuclear plants, but: a) usually maneuvering range is relatively small (60-80% from max output) b) latency is still too big when compared to gas plants and hydroelectric storage. There are some micro-nuclear plant designs, which would be more flexible and more suitable for this scenario, but they are mostly just paper reactors.

I'm pretty sure your parent comment was suggesting the opposite of what you understood them to be suggesting.

I believe they meant the delta time between peaks, rather than the delta power between baseline and peak.

> Renewables don't provide constant power without city-scale energy storage, which doesn't exist (yet) at any reasonable price point.

I think that depends on the shape of the infrastructure. Super-dense cities seem like the least accommodating to near-future renewable/storage tech. Suburbs and rural areas seem like a much better fit to deploy the tech as it matures - which is happening fast.

I can accept that if we include the trend that combinations of renewable tech are clearly closing those gaps.

It seems reasonable that policy discussions about future energy should be increasingly dominated by renewables. That the worth of fossil fuels will steadily diminish toward a niche value ought to be a universally accepted understanding.

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