Washington electric suppliers and utilities are required to inform customers about the fuels used to generate the electricity they sold in the previous year. This disclosure, shared on public websites, acts like a food label, helping customers understand what they are receiving. The disclosure must show the percentage of electricity by fuel type, such as coal, hydroelectricity, natural gas, nuclear, wind and solar. If the utility does not know the source of some electricity, it must label that portion as an “unspecified source.”
The Department of Commerce fuel mix program supports this disclosure by ensuring consistent reporting. More than 60 utilities submit information to Commerce about specific power-generating resources that the utility uses to serve Washington customers.
The Bonneville Power Administration provides the same information for the electricity that it delivers to utilities in Washington. Commerce compiles the individual reports, compares the information to power plant generation data, and summarizes this information in a statewide fuel mix estimate.
The Department of Ecology uses this information to contribute to the state’s greenhouse gas inventory and clean fuel standard.
Utility data
Utilities provide the following information to Commerce in megawatt-hours (MWh):
Total electricity retail sales including power purchases necessary to cover line losses.
- Amounts of specified sources acquired by contract or ownership, by generating resource and fuel.
- Amounts of market or unspecified power used to serve retail load.
- Amount of electricity purchased from BPA.