Pumped Storage Hydropower for Sustainable and Low-Carbon Electricity Grids in Pacific Rim Economies

Because generating electricity significantly contributes to global greenhouse gas emissions, meeting the 2015 Paris Agreement and 2021 Glasgow Climate Pact requires rapidly transitioning to zero or low-emissions electricity grids. Though the installation of renewables-based generators-predominantly wind and solar-based systems-is accelerating worldwide, electrical energy storage systems, such as pumped storage hydropower, are needed to balance their weather-dependent output. The authors of this paper are the first to examine the status and potential for pumped storage hydropower development in 24 Pacific Rim economies (the 21 member economies of the Asia Pacific Economic Cooperation plus Cambodia, Lao PDR, and Myanmar). We show that there is 195 times the pumped storage hydropower potential in the 24 target economies as would be required to support 100% renewables-based electricity grids. Further to the electrical energy storage potential, we show that pumped storage hydropower is a low-cost, low-greenhouse-gas-emitting electrical energy storage technology that can be sited and designed to have minimal negative (or in some cases positive) social impacts (e.g., requirements for re-settlement as well as impacts on farming and livelihood practices) and environmental impacts (e.g., impacts on water quality and biodiversity). Because of the high potential for pumped storage hydropower-based electrical energy storage, only sites with low negative (or positive) social and environmental impacts such as brownfield sites and closed-loop PSH developments (where water is moved back and forth between two reservoirs, thus minimally disturbing natural hydrology) need be developed to support the transition to zero or low-carbon electricity grids. In this way, the advantages of well-designed and -sited pumped storage hydropower can effectively address ongoing conflict around the social and environmental impacts of conventional hydropower developments. Noting the International Hydropower Association advocacy for pumped storage hydropower, we make recommendations for how pumped storage hydropower can sustainably reduce electricity-sector greenhouse gas emissions, including through market reforms to encourage investment and the application of standards to avoid and mitigate environmental and social impacts.