Energy Storage

Simple explanations of energy storage, from batteries to pumped hydro, and why storing electricity matters for the future of energy.

What is pumped-storage hydropower? The battery that makes water work two shifts

Pumped-storage hydropower featured image with upper and lower mountain reservoirs, a turbine-generator, solar panels and a city supplied with electricity at night.

At noon, the grid has more solar electricity than it needs. At dinner, everybody wants power at once. Somewhere in the mountains, a million tons of water have been hired to solve this scheduling problem. They spend the afternoon climbing uphill and the evening falling back down. Nobody calls it elegant. Engineers call it pumped-storage hydropower, and gravity has never missed a shift.