Global Atlas of Closed-Loop Pumped Hydro Energy Storage

The difficulty of finding suitable sites for dams on rivers, including the associated environmental challenges, has caused many analysts to assume that pumped hydro energy storage has limited further opportunities to support variable renewable generation. Closed-loop, off-river pumped hydro energy storage overcomes many of the barriers. Small (square km) upper reservoirs are typically located in hilly country away from rivers, and water is circulated indefinitely between an upper and lower reservoir. GIS analysis of high resolution global digital elevation models was used to determine economically feasible closed-loop scheme locations outside protected and urban areas. This search identified 616,000 potential storage sites with an enormous combined storage potential of 23,000 TWh. This is two orders of magnitude more than required to support large fractions of renewable electricity, allowing flexible site selection. Importantly, the resource is widely distributed to effectively support large-scale solar and wind deployment for electrical grid decarbonization.

Automated summary

Pumped hydro energy storage in closed-loop, off-river settings can overcome the challenges of finding suitable dam sites, providing more opportunities to support renewable energy generation. Through GIS analysis, hundreds of thousands of potential storage sites have been identified, with a vast combined storage potential capable of supporting large-scale renewable electricity development.