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Comment by baz00 | Hacker News Reader

Perhaps we just shouldn't do this?

The environmental impact of AI is already huge and we have an uncertain energy future.

Or perhaps we should. Right now, an unprecedented amount of money is being raised for AI.

If we can somehow turn that into green energy, that’s a big win for the planet. Those nuclear plants will be around a lot longer than the AI “gold rush”.

On the contrary, nuclear power is the greenest energy generation source (in terms of CO2/kWh over the full lifecycle), by far.

https://www.nrel.gov/docs/fy21osti/80580.pdf

Unless you consider the CO2 emitted while you wait for the nuclear plant to come online and displace fossil fuels.

Lifecycle emissions also assume all the parts are being made with current energy mix. In the zero fossil fuel future, where is the CO2 emission for PV coming from? Concrete production? PV uses much less concrete than nuclear per levelized unit of power.

Panels don’t spring from the ether. From mining the silica and other materials that go into PV, to transporting it, refining it, transporting it again, manufacturing the panel and transporting them again across the world (since this all happens in Asia). I too am surprised by the claim that nuclear outperforms its way better and I’m a strong believer that nuclear is the only thing that can get us closer to net 0 than any other.

Here’s a link comparing lifecycle co2 and it does show that nuclear is better: https://www.carbonbrief.org/solar-wind-nuclear-amazingly-low...

The answer, of course, is to do both. PV is great and we should be building massive amounts of it. Nuclear is also great and we should also be building massive amounts of that. They each have pros & cons.

No "of course" about it. Nuclear is struggling to find any reasonable use case. Nuclear and renewables not complementary; you can't economically back up renewables with nuclear.

I'm not aware of any existing or even near-future feasible renewable solution for indoor heating over the winter months in northern climates, other than nuclear.

Nuclear exists, it's proven, it works. And it's not even that expensive. We could build two of the famously overpriced Georgia nuclear plant for the price one guy paid to shut down a social media website. We could build three of them for the price Microsoft paid to buy a video game company. And we could definitely get prices down if we actually wanted to. I think it's really, really bad policy to be quibbling over pennies when discussing solutions to this literally civilization-ending catastrophe that is staring us in the face. We have to do both. If you're worried about economics, it's way more expensive not to be building out every solution we have available to us.

Nuclear is a good solution in many cases. It does us no good to just take it off the table, at least until we actually have better solutions.

> I'm not aware of any existing or even near-future feasible renewable solution for indoor heating over the winter months in northern climates, other than nuclear.

Make hydrogen during the summer (or wind peaks). Store it underground (Europe has space in salt formations for many PWh of hydrogen, for example), use in winter to generate power during dark-calm periods, drive heat pumps with the power.

This is likely to be cheaper than a system that uses nuclear power plants to drive those heat pumps.

Thanks for your reply. There's a good response to that plan here[1], the main takeaways being low round-trip efficiency (lose 50-80% of the energy spent in the process of storing & releasing) and the lack of proven renewable hydrogen generation tech. We should absolutely keep developing this idea and use it in places where it's a good fit. But I'm not willing to bet our future on unproven tech when we have a perfectly good solution right in front of us already working today.

[1] https://theness.com/neurologicablog/hydrogen-takes-another-h...

Neither of those is a good argument. The low round trip efficiency doesn't matter much, because hydrogen is mostly there to deal with unusual events (dunkelflauten). Most of the energy still goes either directly from PV/wind to the grid, or through efficient short term storage. Viewed another way: in a storage system, the "cost of inefficiency" is proportional to the number of charge/discharge cycles; for seasonal or rare event backup the number of such cycles is much smaller than for daily storage.

Lack of proven renewable hydrogen is an argument that would also rule out nuclear. Nuclear fans are constantly pointing to new, cheaper, more wonderful systems, none of which are proven. Even building reactors more cheaply in the west involves a large leap of faith. What we do know is that electrolyzer prices have been falling rapidly, just like renewable generation and battery storage prices have been falling. They're another technology that has large numbers of similar units and has a strong manufacturing experience effect.

> Lack of proven renewable hydrogen is an argument that would also rule out nuclear.

I don't think so. We just built a new plant in Georgia. Minnesota's power grid is already 1/4 nuclear. We've done it before, we can do it again. It would be nice to get costs down, but it's not a requirement. The only thing stopping us is political will and US's general inability to accomplish big things. Hydrogen storage isn't here today (but I hope it will be soon!), nuclear is.

This reduces the environmental impact of AI, and they can use the power plants to power something else in the future.

Innovation is the only way we'll get out of this. Sitting on our asses consuming food for no innovation and a culture of shutting down any attempt like that will only make things worse. This is a good tradeoff for the environmental cost and risks which nuclear brings (which isn't even large).

I don't understand?

> The environmental impact of AI is already huge and we have an uncertain energy future.

This seems like an argument FOR them doing what they're proposing.

Why not? By that logic, humans are a much larger impact and we should depopulate them.

No. We should do more like this if “we have an uncertain energy future”.

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