Pumped-storage hydropower is still the most widely deployed storage technology today, but grid-scale batteries are catching up

Grid-scale storage plays an important role in the Net Zero Emissions by 2050 Scenario, providing important system services that range from short-term balancing and operating reserves, ancillary services for grid stability and deferment of investment in new transmission and distribution lines, to long-term energy storage and restoring grid operations following a blackout.

Pumped-storage hydropower is the most widely used storage technology and it has significant additional potential in several regions. Batteries are the most scalable type of grid-scale storage and the market has seen strong growth in recent years. Other storage technologies include compressed air and gravity storage, but they play a comparatively small role in current power systems.

Annual grid-scale battery storage additions, 2016-2021