A Balancing Act: Examining Climate Impacts on Hydropower at the Balancing Authority Scale

Hydropower will likely play a vital role in a future decarbonized grid due to its flexibility, role as a black start resource, and storage capabilities. However, streamflow-reliant hydropower could face future risks as climate change alters the timing and volume of streamflow. When examining the scale at which electricity supply and demand are balanced, called balancing authority areas, the aggregate impacts of climate risk to hydropower can compound or offset. In this U.S.-wide systems-level analysis, we explore climate risk to hydropower by analyzing potential climate change impacts on streamflow at the four-digit HUC watershed scale using downscaled CMIP5 hydrology projections. We then aggregate risk at the scale of the balancing authority area. Using network science, we find that some balancing authority areas face a greater climate risk due to the geographic location of their hydropower or location in the watershed network. Our results can inform balancing authority planning and collaboration as utilities respond to climate impacts and integrate renewable energy into the grid.