The sites are across 15 EU countries as well as Norway and Switzerland.
The eStorage Project, a consortium of major European electric power stakeholders has published the study that identifies the development-ready sites with existing reservoirs.
Southern Norway is the region with the most potential feasible pumped storage capacity with 1,242GWh or 54% of the study's total, followed by the Alps with 303GWh or 13% of the study's total. The Alpine sites are primarily Austria, France, Italy and Switzerland with 9GWh in the German Alps). The Pyrenees in France and Spain have 118GWh of feasible potential or 5% of the total realisable capacity in the study area.
The eStorage project has been tasked by the European Commission to develop cost-effective solutions for the widespread deployment of flexible, reliable, GWh-scale energy storage across the EU. The scope also includes enhancing grid management systems to allow the integration of a large share of renewable energies. The 2,291GWh identified in the study is over seven times the current installed capacity of pumped hydro energy storage in Europe and more than enough to supply Malta's electricity consumption for a year. It would require 95 million lithium-ion batteries of the type found in most electric cars to provide equivalent energy storage.
Consortium partner DNV GL conducted the study, with the support of the eStorage members, and focused exclusively on existing water body pairs because of the cost advantages of connecting existing water bodies rather than building new reservoirs.
"The qualitative review by leading national hydro experts is what really sets our study apart," said Haike van de Vegte, senior consultant at DNV GL. "For example, our Norwegian hydro expert called any reservoir below 2.5GWh a low priority for Norway whereas for the rest of the study area, experts found reservoirs larger than 1GWh very interesting. Also, the experts were able to provide country-specific requirements on usage of the water or environmental regulations, which could not have been integrated in the case of a desk study only. Consequently, the resulting database of pairs can be considered potentially realisable."