Life Cycle Assessment of Closed-Loop Pumped Storage Hydropower in the United States

Grid-scaleenergy storage is needed to transition to a net-zerocarbon economy, yet few studies compare the carbon impacts of storagetechnologies. Results of this study suggest that pumped storage hydropowerhas the lowest life cycle greenhouse gas emissions compared to otherenergy storage options. The United Stateshas begun unprecedented efforts to decarbonizeall sectors of the economy by 2050, requiring rapid deployment ofvariable renewable energy technologies and grid-scale energy storage.Pumped storage hydropower (PSH) is an established technology capableof providing grid-scale energy storage and grid resilience. Thereis limited information about the life cycle of greenhouse gas emissionsassociated with state-of-the-industry PSH technologies. The objectiveof this study is to perform a full life cycle assessment of new closed-loopPSH in the United States and assess the global warming potential (GWP)attributed to 1 kWh of stored electricity delivered to the nearestgrid substation connection point. For this study, we use publiclyavailable data from PSH facilities that are in the preliminary permittingphase. The modeling boundary is from facility construction to decommissioning.Our results estimate that the GWP of closed-loop PSH in the UnitedStates ranges from 58 to 530 g CO(2)e kWh(-1), with the stored electricity grid mix having the largest impact,followed by concrete used in facility construction. Additionally,PSH site characteristics can have a substantive impact on GWP, withbrownfield sites resulting in a 20% lower GWP compared to greenfieldsites. Our results suggest that closed-loop PSH offers climate benefitsover other energy storage technologies.