Renew and Reinvest: Metro’s zero-emission fleet generates nearly $1.5 million in clean fuel credits
King County Metro’s fleet of close to 300 zero-emission buses has produced almost $1.5 million in clean fuel credits through their use of electricity as fuel.
The funds were generated through Washington’s Clean Fuel Standard. The program is designed to cut climate pollution from transportation, the largest source of greenhouse gas emissions in Washington, by requiring producers and suppliers of transportation fuels to reduce the carbon intensity of fuels over time.
King County and city partners, through the King County-Cities Climate Collaboration (K4C), have been strong supporters of the Clean Fuel Standard as a critical policy tool to reduce transportation pollution in King County. A commitment to supporting and participating in the Clean Fuel Standard with traditional and innovative methods is in the recently adopted 2025 Strategic Climate Action Plan.
“King County remains committed to urgently addressing the climate crisis,” said King County Executive Girmay Zahilay. “Transportation contributes to nearly half of all greenhouse gas emissions in King County, and we must continue advancing the goals of our Strategic Climate Action Plan by investing in cleaner, more sustainable transportation options. The use of the Clean Fuel Standard program gives Metro credit—literally and financially—in their investment toward a zero-emission future.”
“Metro is proud to remain a national leader in the reduction of greenhouse gasses in our transit fleet, said Metro General manager Michelle Allison. “From our electric trolley fleet, to the first purchase of hybrid buses 20 years ago, to the completion of Tukwila Base – our first bus base with a 100% battery electric bus fleet – and through our use of renewable fuels, we’ve reduced the emissions from our bus fleet 45% since 2024, all while growing bus service for our riders.
“The ability to generate funding from the use of our zero-emission fleets shows our continuing commitment to the Strategic Climate Action Plan and to the health of the people of King County.”
Program continues to generate funds to reduce pollution
Suppliers of polluting, fossil fuel-based transportation fuels such as diesel and gasoline must purchase credits from entities supplying or using clean fuels for transportation, such as electricity or low-carbon biofuels. This way, large fleet owners fueling vehicles with electricity, utilities, and suppliers of low-carbon biofuels can generate credits and revenues to further support reducing climate pollution from transportation.
Metro is reducing carbon pollution through the use of electricity to power our battery electric buses and electric trolleys, our original zero-emission vehicles. Metro currently has over 100 battery electric buses and 174 electric trolleys in our fleet.
Metro generated more than 27,000 credits from 2023 through March 2026. Credits were sold this summer generating almost $1.5 million in revenue. Going forward, Metro expects to receive approximately $1 million a year in credit revenue, with variability expected as Clean Fuel Standard credit prices fluctuate over time.
Revenue from the clean fuel credits will help Metro continue to reduce its greenhouse gas emissions—and potentially generate more credits that can eventually be sold, consistent with the investments envisioned in the Strategic Climate Action Plan and Metro’s Next Stop. According to Metro’s Next Stop, approximately one-third of Metro’s bus fleet will be electric trolleys or battery electric buses by 2038.
“This policy is catalyzing the transition to clean fuels by creating revenue for innovation, as well as programs that benefit our local communities,” said Washington State Department of Ecology Director Casey Sixkiller. “King County’s story is a great example of how the Clean Fuel Standard works hand-in-hand with local leadership to accelerate the transition to zero-emission transportation.”
“Our clean fuels program is our best chance to make good on the promise of cleaner air and cleaner vehicles for all Washington drivers,” said James Hove, Washington Director with Climate Solutions. “We have a long way to go, but it’s great to see partners like King County Metro helping lead the way.”
Improving the environment beyond Metro
Other King County departments, including the Department of Natural Resources and Parks and Department of Enterprise Services, are also generating credits via the Clean Fuel Standard program. Like Metro, they will use their revenues to reduce greenhouse gas emissions consistent with direction in the 2024 King County Comprehensive Plan and 2025 Strategic Climate Action Plan.
King County has made a commitment to reduce its greenhouse gas emissions. The Strategic Climate Action Plan calls for a 70 percent reduction in greenhouse gas emissions from County fleet vehicle operations by 2030 (compared to a 2017 baseline). Metro’s participation in the Clean Fuel Standard program supports this effort to improve the health of the region as it generates funds that can assist future efforts to further reduce greenhouse gas emissions.