Green Energy

Nuclear is not renewable. It uses uranium as fuel. It is low carbon and emission free, but not renewable.

There are two solutions to intermittency. First one is a large grid with a lot of differen renewable power sources. It is always sunny somewhere, so when you can move the electrcitiy around, you have much less of a problem. Even better ifyou have wind power as well. With a continent sized grid, you basicly avoid the problem of cloudy days.

Next part is storage. Due to the large grid size you have the ability to use hydro power plants with reservoir as long term storage for particullarily cloudy days or winter and battery and pumped hydro for nights. Biomass is also an option if need be. Maybe we later hydrogen as long term storage as well, for really bad weeks and using it mainly for say chemical plants. Again the better large and interconnected the grid the less storage is needed. In some regions namely large sunny deserts having a nights worth of storage and some emergency backup biomass power plants would be enough. Basicly it runs down to less then a day worth of storage

There are also actually renewable baseloads like hydro power for flow power plants and geothermal, which are also good options. Also variable demand is a thing, which allows for even more renewables.

Seriously intermittency is much less of a problem, then it is made out to be. You just have to add a bit of interconnection and storage to it, but even that is not that expensive and seriousyl usefull.

This is the lie that is told, but nuclear has trouble getting grid penetration over 70% even with massive overprovision and storage via foreign interconnect.

Stable output which is totally interrupted for weeks at a time isn't useful for meeting a combination of stable, variable, and dispatchable loads. Nor does it contribute meaningfully alongside variable output.

There's so much years old anti storage propaganda in your text, it's painful.

Hydrogen storage is not a mature technology yet

What makes a tech mature to you? We have all the components of a hydrogen storage path up and running everywhere around the world. They're not profitable, at least not without government incentives, but solarpunk is anti-capitalist, so profitability shouldn't be among our primary concerns.

something like 35% round-trip efficiency

That's a worst case figure for purely electrical round trip efficiency. We could use waste heat of the fuel cell process (to a lesser extent also the electrolysis process) in order to bump that number up considerably.

not to mention the issues with hydrogen gas leaking due to its small molecular size

That has not been an issue for quite some time thanks to advances in materials science. Also, we could use methanation, of course sacrificing some more efficiency, but then we could even use old natural gas infrastructure without an issue.

Shouldn't even start discussing lithium ion, but the danger of thermal runaway should alone be enough of a reason to plan it very carefully.

Lithium-ion batteries are environmentally bad for sure, but talking about thermal runaway? Really? You need very high temperatures for that to happen. Most stationary storage applications will never see such high powers that they come even close to thermal runaway by themselves. If in a high power application, you'll have better battery management systems supervising the temperature and reducing the allowed power. It's really a non-issue if you have engineers who know what they're doing working on it.

Coming bad to environmentally bad: see sodium-ion batteries.

And if I might add: access to large amounts of water is also an infrastructure and France is already running out of it.

Why would an all nuclear grid need more than a day of storage?

Technically they need 200,000 years worth of storage. Although in that case it's more archival.

And you can't just balance load with nuclear reactors, they take forever (as in days to weeks) to spool up, you can't just switch them on. So you're still going to need some storage capacity and if you're going to have storage anyway you might as well have a simpler energy generation system to boot without all of the big complicated nuclear reactor equipment.

Plus of course the fact that you can stand up solar panels and wind turbines almost anywhere in 6 months, but you'll be wrangling for 30 years to build a new nuclear reactor.

Because they have weeks or months long unplanned outages every year, often correlated and are over-concentrated geographically so fail-over requires huge transmission overprovision.

As to that last, building a $20/W generator and keeping it in hot shutdown to use for 200 hours a year costs thousands of dollars per MWh. There are vastly cheaper ways to get 100 hour storage.

You don't need to remember me the downsides of mining lithium or uranium.

If the numbers are true, my country has the richest reserves of lithium in Europe and one of the richest in the entire world. But the idea of strip minning it does not appeal to anyone and we have a village actively campaigning to not have a mine set up there, regardless the number of jobs ot could bring there.

Regarding uranium, I actually live in an area where it was once mined the land bears the scars. Nobody really remembers how much rock was cut, crushed and hauled away by train in the day.

But this always brings this to mind: why are we not investing in technology to harvest lithium from salt water? I remember hearing it was a viable option growing up.