A 505-MW coal-fired power plant in Colorado is back in operation after spending several days off line due to a fire in its coal storage facility.
The cause of the fire at Xcel Energy's Pawnee Generating Station in Brush, Colorado remains under investigation, Michelle Aguayo, spokesperson for Xcel Energy-Colorado, said in an email to California Energy Markets. The plant was taken off line July 23 and returned to limited operations July 27.
"Our crews are working to extinguish the fire and are making good progress. We have not had any impacts to electric service to our customers," Aguayo said.
County, state and local agencies responded to the fire, according to the Morgan County Sheriff's Office. In addition to the Sheriff's Office, Morgan County Emergency Management, the Colorado Division of Fire Prevention and Control, the Brush Volunteer Fire Department, the Colorado Department of Public Safety and the Northeast Colorado Health Department all participated in the effort.
"We have been working a 23,000 ton coal fire at Pawnee Power Plant since 7:30 this morning in the storage facility," the Brush Volunteer Fire Department posted on Facebook July 19. The Brush VFD also thanked the Fort Morgan, and Hillrose-Snyder volunteer fire departments and U.S. Hydro for their assistance on the fire.
The fire prompted the evacuation on July 23 of all nonessential personnel from the plant, the sheriff's office said in an update posted on its Facebook page. All operations related to the fire were turned over to Xcel and its contractors by 6 a.m. July 25, with other agencies remaining available to support the effort if requested.
"We are grateful to our community partners and responders who have helped with this fire and will continue working with them through this event," Aguayo said.
The cause of the fire has not yet been determined, but it is most likely spontaneous combustion, Aguayo said, noting that such risks are shared throughout the industry. "Coal fires are not fast moving but rather burn slowly, for long periods of time, making them harder to extinguish," she said.
Pawnee's single generating unit is fueled by low-sulfur coal from the Eagle Butte Mine in Gillette, Wyoming, according to an Xcel fact sheet. Low sulfur content is helpful in preventing spontaneous combustion in coal storage, according to the U.S. Department of Energy. The department warns, however, that low-oxygen, bituminous and sub-bituminous coal, typically from Western mines, is more highly combustible than the anthracite coal mined in the eastern U.S., which has a higher carbon content. High moisture content, air circulation in coal piles and "high ambient temperature" are among the factors making a spontaneous coal fire more likely, according to DOE.
Colorado has had weeks of near-record-setting heat, Aguayo said. High temperatures in Brush have been above 90 degrees Fahrenheit for all but one day since July 16, but on July 14, when the fire reportedly started, the temperature reached a high of only 73 F.
Aguayo said Xcel plans to bring the plant back to full operation and that the fire is not likely to affect Xcel's plan to convert Pawnee to run on natural gas in 2029, as announced in the utility's 2021 Colorado Clean Energy Plan (see CEM No. 1636).
A coalition of environmental organizations, led by a national watchdog group that supports environmental whistleblowers and other public employees within local, state and federal agencies, in June drew attention to emissions at the Pawnee plant. Public Employees for Environmental Responsibility and seven other groups in a June 11 letter to the Colorado Department of Health and the Environment said independent modeling indicates the plant exceeds federal limits for sulfur dioxide emissions and that Pawnee is in violation of the federal Clean Air Act and Colorado's Data Requirements Rule.
CDPHE in a statement said that in evaluating the modeling submitted for the facilities, it followed stringent U.S. Environmental Protection Agency guidelines and modeling protocols for each facility.
"When the EPA updates guidelines, we update our protocols," the statement says. "As a result of actions taken at the state level and local level, sulfur dioxide emissions from these facilities have been declining steadily."
"We have been monitoring the site to assure the safety of our people and the surrounding community," Aguayo said. State fire officials placed two air quality monitoring stations in Fort Morgan and Brush as part of the fire response, she added. "Based on the monitoring, we have not identified any public health concerns associated with the fire."
Aguayo said Pawnee operates with low SO2 emissions and was retrofitted with state-of-the-art SO2 emissions controls "only a few years ago."
"The plant is currently in compliance with all applicable permitting requirements," she said.