1340
‘Energy independent’ Uruguay runs on 100% renewables for four straight months
(theprogressplaybook.com)
This is a most excellent place for technology news and articles.
There is actually. Pumped Storage hydro uses the energy as it's generated from renewables and uses it to pump water up into a reservoir. Once you have the water pumped, it's just a matter of letting the water back out through turbines. Their efficiency is somewhere around 80% which is pretty good.
For that you need both suitable hills and water. Also it's not that huge, it certainly depends on the reservoir capacity. If it was a feasible solution, then you'd see them everywhere, but you don't. Ask Germans about it.