Abstract

Climate strongly affects energy supply and demand in the Pacific Northwest (PNW) and Washington State (WA). We evaluate potential effects of climate change on the seasonality and annual amount of PNW hydropower production, and on heating and cooling energy demand. Changes in hydropower production are estimated by linking simulated streamflow scenarios produced by a hydrology model to a simulation model of the Columbia River hydro system. Changes in energy demand are assessed using gridded estimates of heating degree days (HDD) and cooling degree days (CDD) which are then combined with population projections to create energy demand indices that respond both to climate, future population, and changes in residential air conditioning market penetration.

We find that substantial changes in the amount and seasonality of energy supply and demand in the PNW are likely to occur over the next century in response to warming, precipitation changes, and population growth. By the 2040s hydropower production is projected to increase by 4.0-4.2% in winter, decrease by about 13-16% in summer, with annual reductions of about 2.5-4.0%, with larger decreases of 18-21% in summer projected for the end of the 21st century. Although population growth is projected to increase heating energy demand overall, warming results in reduced per capita demand. Residential cooling energy demand, however, increases rapidly (both overall and per capita) due to increasing population, cooling degree days, and air conditioning penetration.