Sand Batteries

[william webster]

Google this article -

World’s first sand-powered battery is ready to heat homes​

Researchers say the Finnish innovation could help solve the problem of how to store renewable energy such as wind and solar

 

[windeguy]

Sand (or similar things to sand) to store heat. Interesting. They did point out that sand is in short supply, so sand like materials will be needed instead.
I didn't see anything on how they were converting that stored heat into useful amounts of electricity, but I imagine they have their ways. I got a lot of sand around my house... Water table is about 8 feet down.

 

[Sailor51]

newatlas.com/energy/sandbattery
Not something you could have in your backyard.

 

[windeguy]

Whatdyamean? I got room: