A global atlas of pumped hydro systems that repurpose existing mining sites

Large amounts of energy storage are required to support high levels of solar and wind power. Pumped hydro energy storage comprises the majority of global energy storage for the electricity industry. A previous study identified 616,000 potential "Greenfield" closed-loop (off-river) pumped hydro sites around the world with combined storage of 23,000 Terawatt-hours (TWh). In this study, we identify 904 sites in mining areas ("Brownfield") with combined potential storage of 30 TWh. A high spatial resolution global atlas of Brownfield closed-loop pumped hydro energy storage systems is available online. It was developed through Geographic Information System (GIS) analysis of a digital terrain model. The GIS algorithm identified mining pits, pit lakes, and tailings ponds within mining sites and located nearby reservoirs that could form a suitable pair. All Brownfield pumped hydro sites were assigned a cost class of A to E to allow comparison between sites on the global atlas. There are far fewer Brownfield than Greenfield options, with 77 countries found to contain eligible locations. Despite the smaller number of eligible locations, Brownfield sites typically have other advantages including existing transmission infrastructure, water pumping infrastructure, road access, social licence and reduced environmental impact for development on disturbed land.