In 2018, the combined nameplate capacity of all utility-scale resources in the Western Interconnection was 258,200 MW. Approximately 1,300 MW of wind and solar capacity were added and natural gas capacity increased by 900 MW.
Different subregions of the West have different resource portfolios. Hydro units are dominant in the Northwest, while California and the Southwest rely heavily on natural gas. Solar units have become prevalent, especially in California, as wind capacity has grown in the Rocky Mountains and along the Columbia River.
