Comment by jlevers | Hacker News Reader

Comment by jlevers | Hacker News Reader

> In work published last year in the journal Joule, Sepulveda and his co-authors made a powerful case for using a mix of renewable and “firm” electricity sources, such as nuclear energy, as the least costly, and most likely, route to a low- or no-carbon grid.

> Recognizing that “absolutes exist in people’s minds, but not in reality,” Sepulveda sought to develop a tool that might yield an optimal solution to the decarbonization question.

The second part, I think, is very important to keep in mind when discussing whether or not to use nuclear to help solve the climate crisis. I'm not a big fan of nuclear, but if deploying huge amounts of it is what it takes to get us to zero carbon emissions by 2050, I'm for it. Yes, nuclear has its risks, and it's not renewable, but I think it would be worth pursuing as a stepping stone to get us to net-zero emissions sooner, while we figure out how to power the entire world via truly renewable energy. IMO, the potential risks of failing to address climate change rapidly enough are much larger than the risks of wide-spread nuclear power.

Nuclear is renewable through uranium seawater extraction: https://www.pnnl.gov/news/release.aspx?id=4514

The uranium in seawater is same as uranium in the ground, not renewable.

Uranium in seawater is available in much larger quantities. We would not consume the amount of uranium over the next billion years even if we used nuclear for all of humanity's energy demands [1]. It is renewable in all but the most literal sense.

Uranium in seawater is the same as the hydrogen in the sun: it's not renewable. The hydrogen in the sun will eventually be fused to such an extent that no further energy will be released. There is no such thing as a renewable energy source because the laws of thermodynamics dictate that there is a finite amount of usable energy in the universe.

https://www.forbes.com/sites/jamesconca/2016/07/01/uranium-s...

Renewable in the context of energy policy means that it continuously renews on Earth on human timescales.

I agree that with uranium it's not really relevant in practice due to the large supply of it.

While I agree with you that it's virtually impossible for humans to use up the uranium in sea water at our current energy consumption rate, I think it's worth thinking about that if we had "unlimited" energy, we might use orders of magnitude more of it than we currently do.

That being said, for that to be an issue, we'd have to increase our energy consumption at least 1000x, and if we get to the point of using that much energy, it seems likely we'll also have advanced technologically to such an extent that we'll figure out another solution. It's just an interesting exercise to consider how what seems impossible today, might be totally routine in 10/100/1000 years.

The typical slight of hand in such studies is to ignore long term storage, like hydrogen, and then conclude nuclear is needed instead of all-renewables.

A good argument against (long-term) storage could be that it does not exist yet. Not in commercial quantities at least. I think it would be accurate to state we can build nuclear in sufficient required TWh's right now, but we could not do the same for the storage we would need in a 100% renewable scenario.

More and more I think we just don't have the time for research anymore, and we should prioritize getting rid of carbon over going as green as possible. (Naturally I will agree that renewable is ultimately better than non-renewable nuclear.)

Ah, the old "nothing ever happens for the first time" argument. A terrible argument, actually.

Hydrogen storage underground is a proved technology, already in use. Hydrogen pipelines exist. I'd argument the step to using hydrogen for long term storage is much more plausible than that nuclear will suddenly get off the failure curve where it gets more expensive over time rather than cheaper.

I'd love to see you support your argument!

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