Washington state agencies’ biodiesel consumption falls in 2024

In Washington state, a new report from the state’s Department of Enterprise Services shows that during 2024, state agencies, including universities, bought just under 1.55 million gallons of biodiesel, representing 8.45% of all fuel purchased to power diesel vehicles, vessels, equipment, and fire boilers to heat and power facilities in Washington. This is a 1.04% decrease from 2023, when the biodiesel use was 9.49%.

The Washington State Department of Transportation (WSDOT) buys the most biodiesel of all state agencies. WSDOT purchased 1.54 million gallons of biodiesel in 2024, representing 99.4% of state agencies’ use. WSDOT’s Washington State Ferries (WSF) division accounts for 93% of all biodiesel purchases. WSF purchased 1.4 million gallons of biodiesel in 2024, a 0.1% increase from 2023. WSF averaged 9.4% biodiesel, down by 0.2% from 2023.

During 2024, all other WSDOT divisions purchased 102,552 gallons of biodiesel, representing 6.62% of the state’s biodiesel purchases. WSDOT’s average blend level was 4.5% biodiesel, which was 6.8% lower than its 2023 level due to expanding use of renewable diesel (R99).

The state departments of Corrections, Natural Resources, and Fish and Wildlife bought a combined 9,741 gallons of biodiesel, representing only 0.63% of total biodiesel purchases. Agencies purchased a total of 283,385 gallons of heating fuel and 18 million gallons of vehicle fuel.

WSDOT (excluding WSF) expanded its use of R99 statewide. However, challenges with deliveries limit the use of R99 in the Southwest Region. In 2024, WSDOT replaced 1.2 million gallons of petroleum diesel with R99. WSDOT’s average 2024 renewable diesel blend level was 52.6% in 2024. When we combine biodiesel (B100) and R99, WSDOT’s total diesel purchase of biomass-based blend increased to 57.1%.