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.
How much energy is generated versus how much is used to pump water back up?
It generates exactly as much as the grid currently needs and then everything beyond that pumps the water.