• In 2021, Northwest imports had a highest share of generation from RPS-eligible renewables—35.5 percent of the state’s total renewables (not including hydro) in the power mix came from Northwest imports, and 28 percent came from Southwest imports. Notably, RPS-eligible renewable imports from the Southwest have been increasing (+7.1% from 2020, +30.2% from 2017), while imports from Northwest have decreased by 12.4 from 2020. Much of that decrease is due to the 12.8 percent reduction in wind, as it contributed the most to the Northwest imported renewable power mix in 2021 (86.3 %). 2021 marked the first time, since 2013, when RPS-eligible renewables imported from the Southwest decreased.
  • Imports from the Southwest are more carbon intensive due to having a higher percentage of generation from coal (15% in 2021) compared to Northwest imports (0.5%) and in-state generation (0.2%). However, coal’s share of Southwest imports has declined from 30 percent in 2010. Still, in 2021, California imported more coal from the Southwest (+12%) compared to the previous year. Moreover, a large portion of California’s imports come from “unspecified sources” that are untraceable to specific generating facilities.129 Given the almost complete absence of fossil fuel sources in specified Northwest imports (coal, oil, and natural gas made up less than 1 percent of these imports), it is plausible that most of the GHG emissions from Northwest imports are from unspecified sources.

129 According to California Energy Commission, unspecified sources of power are typically a mix of resource types, and may include renewables. This category can also include spot market purchases, wholesale energy purchases, and purchases from pools of electricity where the original source of fuel can no longer be determined. Retrieved from: https://www.energy.ca.gov/data-reports/energy-almanac/california-electricity-data/2021-total-system-electric-generation