2020 was the most active wildfire season in recent history. This study leverages solar models to quantify the solar impacts of wildfire smoke in western North America 2001 – November 2020. We observe a sharp increase in the number of days impacted by aerosol events. Record deviations in clear sky DNI are found at the Hanford, CA, Boulder, CO, and Desert Rock, NV study locations. Total sunlight (GHI) for September was diminished by up to 20% in some locations; California’s Central Valley and parts of the Columbia River Basin were hardest hit by the smoke. At the Hanford study location, the Aug.- Oct. 2020 deviations in modeled energy output totaled -5.9% of the historical annual average (2001-2019). The analysis demonstrates that wildfires are an important risk to production for solar projects in western North America.
