Comment by mnahkies

> we can dig holes and transfer materials into anything we need with the practically free daytime energy.

I guess you mean stuff like this https://gravitricity.com/ - I believe there's a few old coals mines in Scotland that have (/in progress) been retrofitted as gravity batteries to store renewables which is pretty cool (https://www.bbc.co.uk/news/articles/c5yd18q248jo)