Assessing Climate Change Impacts on Electric Power Generation in the Western Interconnection

Abstract:

In recent years, concerns have grown over the potential impacts of climate change on electricity generation. Water resources are integral to the production of thermoelectric and hydroelectric power, and droughts are expected to become more frequent, severe, and longer-lasting over the course of the twenty-first century. Many generation technologies—including gas turbines and solar cells—are also vulnerable to changes in local climatic conditions like ambient air temperature. As extreme weather becomes more common, methods are needed to assess the impacts of climate change on regional power systems. However, these methods must also account for (1) heterogeneity in generation technologies, and (2) local variation in climatic conditions. This study uses a physically-based modeling system to assess the vulnerability of electric power infrastructure in the Western Interconnection. Climatic and hydrologic parameters relevant to power generation are identified for six generation technologies. Downscaled climate forcings are then used as inputs to a physically-based modeling system, consisting of the Variable Infiltration Capacity (VIC) hydrological model and the RBM one-dimensional stream temperature model. Impacts to generating capacity are estimated directly from changes in modeled climatic and hydrologic parameters, using functional relationships unique to each generating technology. A preliminary analysis of 1,302 power stations in the Western Interconnection reveals decreases in summertime generating capacity of 8-22%, with the largest impacts occurring at thermoelectric and hydroelectric facilities in the Pacific Northwest and California. Impacts to base-load thermoelectric plants are mitigated by recirculating cooling systems, which reduce the performance penalty of low flows and high water temperatures. Climate impacts on solar and wind capacity are relatively small, indicating that these energy sources may play a more prominent role as conventional generation sources become less reliable.