Commerce produces fuel mix disclosure information by combining results from more than 60 utilities to determine an aggregate mix for the entire state. This information is also used to report the greenhouse gas emissions from the state’s electricity sector.

Each electric supplier serving retail customers in Washington must disclose to its customers the mix of fuels used to generate the electricity sold to them. The fuel mix is based on the generating plants and contracts of each utility and the Bonneville Power Administration, and it also includes information on fuel used to generate electricity purchased in wholesale spot markets. Utilities report their sources of electricity to Commerce, and Commerce combines this information with data from wholesale markets to determine a fuel mix for each utility.

Utility Data

Utilities provide the following information in megawatt hours (MWh):

Total electricity retail sales including power purchases necessary to cover line losses.
Reliance on market power to serve retail load (spot market).
Amount of electricity purchased from BPA.