I know not every where is suitable for reservoirs but this seems pretty obvious. Run renewable to pump the water up hills, all the 'battery' components of the tech are well established. You're creating additional benefit by storing potentially potable water. It seems like the tech for water storage/ transport/ regeneration to electricity is all pretty well figured out. I'm thinking some place like the Columbia gorge where there is high capacity for wind and for hydro.
I know not every where is suitable for reservoirs but this seems pretty obvious. Run renewable to pump the water up hills, all the 'battery' components of the tech are well established. You're creating additional benefit by storing potentially potable water. It seems like the tech for water storage/ transport/ regeneration to electricity is all pretty well figured out. I'm thinking some place like the Columbia gorge where there is high capacity for wind and for hydro.