alt Hacker News> You need to have batteries that can store power for at least a week to have base load as reliable as nuclear power.
This is a complete myth, somebody pulled "a week" out of their butt a decade ago, it gets repeated a ton, but it's not based on reality or studies or numbers. This is a consistent problem with online nuclear advocacy: there's no basis for the numbers, nobody calculates anything, and if they bother to do a calculation they only calculate the upper bound and then assert "see look a big number" and say that's a proof of impossibility.
What event requires a week of storage? Nobody can name one! When has there been a week with zero generation? No one can name it! The assumptions that one has to make up in order to make a "week" even sound plausible are in turn themselves so implausible.
> There isn't enough battery capacity in the world to do this for a state like California, let alone the whole country.
Imagining there's a fixed battery capacity is a very short sighted view, it's growing by 10x every year.
So let's take your "week" as the measure, even though it's wrong. If we're at 2-3 TWh of world battery production capacity in 2025, that's 4 days of California demand. By 2031 or 2032, we're going to have 20-30TWh of battery production.
Replies
> By 2031 or 2032, we’re going to have 20-30TWh of battery production
What’s the source on this? I just googled it, and the sources I see are saying 5TWh by 2036, with increasing supply chain risks over time…
https://finance.yahoo.com/news/global-lithium-ion-battery-ca...
https://www.iea.org/commentaries/global-battery-markets-are-...
> If we're at 2-3 TWh of world battery production capacity in 2025, that's 4 days of California demand. By 2031 or 2032, we're going to have 20-30TWh of battery production.
The 2,200 GWh of batteries produced in 2025 amounts to a bit under 3 days of California's average 750GWh daily electricity consumption, not 4 days. And more broadly, I'm not sure how pointing out that a year's worth of global battery production amounts to just 3 days of one US state's electricity demand is supposed to demonstrate that battery storage is feasible.
To put this in perspective, global daily electricity demand is 60,000 GWh. Of the ~2,200 GWh of batteries produced in 2025, only ~300 GWh was used for grid storage. Most of it went to EVs.
Battery production costs are already dominated by the cost of anode and cathode material. The bottleneck is resource extraction. And the nature of scaling resource extraction is that the easiest-to-exploit reserves are extracted first, and increasing producing involves reaching for the more and more difficult to access reserves.
Even if production continues to rise, any serious investment into battery grid storage will delay EV adoption as batteries are diverted to grid storage instead of EVs.