- Wholesale power prices are increasingly turning negative at times of high solar output
- Observers say rooftop solar is “cannibalising” electricity prices and hitting large-scale solar hard
- There are calls for storage and greater daytime demand to help soak up solar production
There was a company that stacked concrete bricks to store electricity, with the point being that on demand the crane could pick up bricks and gain the energy from dropping them down. Hit all sorts of news sites, never heard of it reaching practical use.
EDIT as noted by another commentor, apparently it did.