Modeling the water systems of the Western US to support climate-resilient electricity system planning

Because of these interdependencies, the threat of climate change to WUS resources will likely have compounding electricity impacts on the Western Interconnect grid. This study describes a WUS-wide water system model with a particular emphasis on estimating climate impacts on hydropower generation and water-related electricity use, which can be linked with a grid expansion model to support climate-resilient electricity planning.

The water system model combines climatically-driven physical hydrology and management of both water supply and demand allocation, and is applied to an ensemble of 15 climate scenarios out to 2050. Model results show decreasing streamflow in key basins of the WUS under most scenarios. Annual water-related electricity use increases up to 4%, and by up to 6% during the summer months, driven by growing agricultural demands met increasingly through a shift toward energy-intensive groundwater to replace declining surface water.