To make solar power viable, we need a solution for overnight energy storage.
Batteries are complicated.
Do you know what isn't? Water go up. 
To make solar power viable, we need a solution for overnight energy storage.
Batteries are complicated.
Do you know what isn't? Water go up.
The storage and generating capacity is much less, but flow batteries are still good.
You don't necessarily need a giant reservior, you can flood old mining sites like this - https://naif.gov.au/our-projects/genex-kidston-pumped-hydro-storage-project/