Storage that is good enough to replace peaker plants, and storage that is good enough to handle seasonal variations in insolation are completely different ballgames. The lithium battery chemistry in your phone will self-discharge on the order of a month - there are alternate chemistries but they have other problems right now.

> seasonal variations

Or overbuild renewables reducing the seasonal variations. In cost terms when compared to nuclear power those would be insignificant.

With fossil based energy systems we didn’t match production capacity to consumption 100% with peakers having low capacity factors.

But somehow we can’t overbuild a kWh and need massive seasonal storage when it comes to renewables.

Yes, if you have a magic planet spanning transmission system capable of handling the power flows over building solves the problem. Unfortunately that's orders of magnitude more expensive than storage, which we already can't afford.

Gonna have to see more numbers for "storage is more expensive than nuclear". And not the unit cost of SMRs with the assumption that mass manufacturing is solved, certified, and permitted. You have to account for those costs too. And time, of course. The climate crisis is here now. We can't wait 10 years for cheap SMRs to be ready (though we'll gladly take them when they are).

I’ve never seen anybody give an estimate for the cost of storage required to fully convert the grid of e.g. the US that wasn’t obviously astronomical and not something the utilities could afford the capital for. If you’ve seen different please share.

I still don't see numbers. What is this "obviously astronomical" estimate? And how does it compare to nuclear, in any form?

Battery storage ranges from $150 to $300 / kwH capacity. The entire grid would need something like 5twH of capacity for an 8 hour ride through. I want you to carefully consider those prefixes and the vast, vast Gulf of space between them.

Nah, you can buy retail packs for less than $300/kwh now, I installed some recently. Commercial installs in China are reportedly hitting like $60 installed.

Also, 4 hours is the target Jigar Shah talks about for getting solar to a load factor roughly equal to most thermal plants.

Also, I believe that’s 4 hours on the nameplate of the variable generation, not 4 hours on the entire grid load. People generally aren’t advocating for going fully variable generation.

I see the issue. You are relying on information that is many years out of date. Your upper span is soon a magnitude out of date.

https://www.ess-news.com/2025/06/26/china-energy-engineering...

Also please give a source as to why the US grid would need 5 TWh of battery storage. So we know it is not simply a number you invented out of thin air to say ”impossible!!!!”