We're not seeing a lot of realistic numbers published for the cost of a 100% renewables + storage grid because there is the X factor of "How many outages can you tolerate?"

Storage over a 24 hour period is one thing, the economics don't look difficult at all. In places like Upstate NY, however, usable insolation can vary by a factor of 3x between summer and winter. You can overbuild solar panels by 3x or you can add a few months of storage which costs a lot more than a few hours or days worth of storage. There is also the issue of

https://en.wikipedia.org/wiki/Dunkelflaute

It would be great to have a backup energy source which is fully and economically dispatchable and environmentally benign but it's not there. I suspect there is some point of required reliability where adding nuclear baseload makes the grid more reliable economically compared to building months worth of storage. See

https://www.sciencedirect.com/science/article/pii/S136403212...

also nuclear power plants are capable of load-following

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

it's just not an optimal use of the capital. The Gates foundation has been researching LMFBRs that use thermal batteries to improve load following abilities.

You might think dispatchable natural gas fired plants with some kind of carbon capture would help but with amine-based carbon capture the capital cost is high, just like with nuclear, so you are looking at a high multiple of what it would cost to add carbon capture to a coal plant that runs continuously. Calcium-based chemical cycling, metal-organic-frameworks and such offer some hope for lowering costs but probably not enough for those scenarios.

The real criticism of nuclear at this point in time is that any new plants are a decade out. It's a reason to start early, but no matter how you slice when the next NPP goes online in the US the amount of solar and wind added to the grid between here and now will dwarf it.

You raise good points, but I think none of the anti-renewable arguments are really show-stoppers, mainly because of how cheap things have become; solar panels are cheaper than glass windows now and prismatic LiFePo cells are down to ~$60 for 1kWh at single digit quantities (!!).

Figuring out the most economical mix of overprovisioning, improved grid connectivity, battery storage and more exotic longer term storage (synthetic gas/heat/fossils + capture/etc.) is a problem that is IMO best solved by the market over time.

I also think it is very telling how even a nation like France, which is basically in the perfect position to stick with nuclear power over renewables is still building out wind/solar rapidly. Nuclear power not even managing to defend its home turf makes it very questionable to fully bet on it elsewhere.

> You might think dispatchable natural gas fired plants with some kind of carbon capture would help but with amine-based carbon capture the capital cost is high, just like with nuclear, so you are looking at a high multiple of what it would cost to add carbon capture to a coal plant that runs continuously. Calcium-based chemical cycling, metal-organic-frameworks and such offer some hope for lowering costs but probably not enough for those scenarios.

I think you are missing far simpler solutions for what is in terms of TWh needed a tiny problem.

Why not just use biofuels, synfuels or hydrogen?

Whatever the aviation and the maritime shipping industries settles on since they are unable to in the foreseeable future decarbonize with batteries.

The US today produces enough ethanol for gas blending to run the entire grid for 16 days without help.

As we switch to BEVs it is trivial to repurpose that for the grid, while also ensuring that the inputs decarbonize as well.

If you are not an ideologue the reality is that it's not really possible and not a serious option.

Modern society/civilisation relies on reliable power generation on cue, wanting to gamble that ability just to be able to remove nuclear because "it's too expensive" is beyond stupid. The cost of a long blackout is so much worse than anyone pretending otherwise is a fool.

As for storage solutions, even if they were existing and dirt cheap there is the problem of capacity sizing. How much do you build for? One week, two weeks, one month? If renewable generation cannot recover for a single day more than you planned for, you are done.

In a world where climate is constantly changing and the rate of change is increasing; it is crazy to be willing to put everything in solutions entirely depending on this.

We have to build renewables, they make sense for the low hanging fruit, but only doing renewable is just foolish. And this is exactly why nuclear makes sense, no matter how much it costs.

People on HN all seem to be venture capitalist, only thinking about cost/profits as if that should be sole motivator for doing things. That's just sad.