The relationship between pumped water storage and hydrogen solar container

PSH complements wind and solar by storing the excess electricity they create and providing the backup for when the wind isn’t blowing, and the sun isn’t shining. PSH absorbs surplus energy at times of low demand and releases it when demand is high. The idea for pumped hydro storage is that we can pump a mass of water up into a reservoir (shelf), and later retrieve this energy at will—barring evaporative loss. Pumps and turbines (often implemented as the same physical unit, actually) can be something like 90% efficient, so the round-trip. Malcolm Turnbull, President of the International Hydropower Association, says it’s not a choice between batteries and pumped hydro.