Study Examines Sustainability of New Closed-Loop Pumped Storage Hydropower

Published in August 2022, the Life Cycle Assessment for Closed-Loop Pumped Hydropower Energy Storage in the United States study explores the potential environmental impacts of new closed-loop pumped storage hydropower (PSH) projects in the United States compared to other energy storage technologies. The authors, who are from the National Renewable Energy Laboratory, compared data on PSH and alternative energy storage options and found that across many future energy scenarios and grid mixes, PSH plants contribute the least to global warming potential. 

This study is the first to examine the full life cycle of new closed-loop PSH projects—from resource extraction through operation and on to end-of-life material recovery (or disposal)—focusing on greenhouse gas emissions. Such data can help industry build investor confidence by demonstrating that PSH can be a valuable and sustainable addition to tomorrow’s clean energy grid. Before this study, relatively little was known about the environmental impacts of constructing new, closed-loop PSH plants. Now, the team’s findings could help stakeholders strategize how to sustainably grow the industry.  

For example, though the team based its research on a plant with an 80- to 100-year lifespan, the results represent a range of potential plant specifications and geographic locations. And larger plants, according to the study, could have lower overall lifetime carbon emissions. Developers can use this data to accurately assess their proposed plant’s emissions, and the results could help inform decision making about future investments in new closed-loop PSH projects versus other energy storage technologies. A Technical Review Committee, which included nine representatives from industry and academia, as well as Argonne National Laboratory, provided valuable guidance to the report’s authors and contributed advice on data sources, assumptions, modeling approach, and dissemination to stakeholders.