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Comment by ComradePhil | Hacker News Reader

Even if you fill the entire world in solar panels and wind mills, we won't have reliable 24-hours energy. That means you can't rely of constant supply of it, which means you'll need something as a backup.

Nuclear is one of the most reliable sources. The world has enough uranium for at least a few hundred years, which in practice could be much much longer depending on if we can keep installing more renewable plants. So, why not use nuclear as a backup? There is nothing even close to a better option than that.

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I’m definitely in favor of keeping and upgrading existing plants and building some new ones, but there’s no source of energy that has 100% availability. A few years ago, France had 1/3 of its reactors offline at the same time for maintenance.

Indeed we would have to build enormous overcapacity with wind and solar to achieve 100% uptime, but until we perfect energy storage, that’s true of any energy source today.

> A few years ago, France had 1/3 of its reactors offline at the same time for maintenance.

And the wind stopped blowing several times today, the sun was only around for a few hours.

There's a clear difference. I invite you to think about it.

> Indeed we would have to build enormous overcapacity with wind and solar to achieve 100% uptime

Except, that does not guarantee 100% uptime, not by a long shot, regardless of how much over-capacity you build. One area not having wind usually means that there is no wind in a much larger area close to that. If you have wind in another part of the globe, that is useless to you because it can't be transmitted to your place; too much transmission loss for it to be viable.

Similarly, if you don't have sun, it is very likely that your entire hemisphere doesn't. So, it is crucial to have backups that are more reliable than that... and there is nothing that is better than nuclear for this... at least as of now.

Yes you can in theory power the entire world with renewables. The sun is always shining and the wind is blowing somewhere. Of course, doing that would be stupid because of the diminishing returns.

But the same is true of nuclear power. Not even France tries to provide 100% of power with nuclear, because it would be an absurd over-investment to handle a few peaks or unexpected maintenance periods.

It’s pointless to argue that renewables can’t provide 100% of power, because in theory any single source of energy could, and in practice no single source of ever should.

This is a big false equivalency. Nuclear uptime is orders of magnitude better than solar or wind.

Capacity factor for wind at sea (North Sea at least) is typically above 40%.

So nuclear can be at most a factor of 2.5 better. Given how cheap wind is, you can easily overbuild a factor of 2.5 and still be cheaper than new nuclear.

You cannot make those multiplications. When there's no wind, having 2.5x the wind turbines doesn't help at all. In very general terms, adding a 9 to the reliability stats on engineering projects, usually adds an order of magnitude in the cost.

But more importantly, nuclear plants are up WAY over 90% of the time. If they need to do maintenance, they do one reactor at a time in the 4-5 reactor plant. This is similar to how they do maintenance on one turbine at a time in a hydro plant.

Nuclear, wind, solar, they all need storage. Wind and solar because sometimes there is no wind or sun. Nuclear because building out for peak capacity is unaffordable.

But I responded to 'Nuclear uptime is orders of magnitude better than solar or wind'. That is simply not true. Uptime cannot be 10 times better. It could be rephrased as the downtime of nuclear is one order of magnitude smaller than wind. But even that is not clear. And certainly not 'orders of magnitude'.

The "backup" for nuclear is another nuclear plant. It is unlikely that both will go down at once.

This won't work with solar or wind becuase no sun in one location usually means no sun in a much larger area around it. Same for wind.

The sun and wind much further away are of no use because it is not practical to tranmit that electricity to the location it needs to be.

The existing nuclear plants have ceased production once every few years at the worst. In contrast, wind mills and solar panels stop producing electricity multiple times everyday.

Nuclear cannot do peak power in any affordable way. So it doesn't matter how reliable nuclear is, if there is not enough power in late afternoon/early evening then the grid is broken.

Given the current costs for nuclear power, you can do a lot of crazy stuff with wind and solar (like transporting it over long distances) and still be cheaper than nuclear.

This is absolute nonsense. Of course nuclear can power up and down. Who told you it couldn't? The fuel costs of nuclear are a tiny tiny portion of the operating costs, so it's trivially easy to power on/off the reactor.

Also, the long distance transport costs for electricity are massive - can be 30% loss. Look at HydroQuebec. They massively overproduce just to transport over HUGE long distance power towers because of the huge losses - and that's only 500 miles.

This is incorrect

Please explain.

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