Comment by ZeroGravitas

Solar has progressed so fast that only the most insanely optimistic predictions were accurate in the end.

I'd guess batteries are also at that stage.

Googling it seems that is correct eg:

> In 2017, U.S. grid storage developers promised they could deliver 35 gigawatts by 2025. They beat their target and made batteries a key power-sector player.

> That goal sounded improbable even to some who believed that storage was on a growth trajectory. A smattering of independent developers and utilities had managed to install just 500 megawatts of batteries nationwide, equivalent to one good-size gas-fired power plant. Building 35 gigawatts would entail 70-fold growth in just eight years.

https://www.canarymedia.com/articles/energy-storage/grid-sto...