CENTRALIA, Wash. — The TransAlta power plant in Centralia is on track to stop burning coal and start running on natural gas by 2028.
According to a Department of Ecology press release, the plant would then be used mainly when extra electricity is needed in the region. The agency said that setup would still rely on fossil fuel, but would produce less greenhouse gas than the plant did when it ran on coal.
The Department of Ecology said the change would cut most harmful air pollution tied to coal, but one type of pollution called volatile organic compounds would increase. It also said TransAlta agreed to spend between $7 million and $21 million on clean energy projects in Lewis and Thurston counties, based on how much the plant emits each year.
People can comment on the environmental review and draft air permit until 11:59 p.m. Sunday, Sept. 6, 2026. Those comments will also help shape a new grant program connected to the switch.
State officials said TransAlta planned to stop using natural gas at the Centralia plant in 2044. That would put the plant ahead of the state’s 2045 clean energy deadline.
The plant began burning coal in 1972 and for years was the biggest single source of greenhouse gas emissions in the state, according to the press release. It also released large amounts of sulfur dioxide and nitrogen dioxide.
TransAlta agreed in 2011 to end coal use at the plant by 2025. One of the plant’s two generating units shut down in 2020 and the second had been scheduled to close at the end of 2025.
The press release said TransAlta reached a deal with Puget Sound Energy in December 2025 to change the last operating unit to natural gas and make up to 723 megawatts available when needed.
That same month, the U.S. Department of Energy ordered TransAlta to keep the Centralia plant ready to operate as a coal plant. The press release said that order had been extended twice, but the plant had not been asked to provide power to the grid since mid-December.