September 24, 2026 - The trouble-plagued Comanche 3 coal-fired power plant — the largest generating asset on Xcel Energy’s Colorado grid — is back online and generating electricity after a year of repairs.

The unit broke down in August 2025. At the time the company said “elevated vibrations” set the turbine offline and led to “notable damage to the unit.”

Xcel said it hoped to have the unit back in service in June, but the restart date was pushed to July and then to August, raising concern there would be inadequate generation capacity during what proved to be the hottest Colorado summer on record.

To help fill the gap, the life of the 50-year-old Comanche 2 unit, which was scheduled to close at the end of December 2025, was extended by the Colorado Public Utilities Commission.

Comanche 3 went back online the evening of Sept. 1, the company said in a report filed this week with the Colorado Public Utilities Commission. 

The total cost of repairs is expected to be between $15 million and $26 million, with Xcel Energy’s share, after insurance payments, estimated at $4.6 million, the report said.

The 750-megawatt generator, however, is running at only 200 MW to 300 MW of capacity, according to Joseph Pereira, director of the Colorado Office of the Utility Consumer Advocate, or UCA, which represents residential and small commercial customers before the utilities commission.

It isn’t clear at what level the plant will run, Pereira said, adding “and just because it is running now we don’t know how long it will run.”

Since it opened in May 2010 (six months behind schedule), the $1.3 billion plant has been bedeviled by breakdowns and shutdowns.

A 2021 PUC staff report estimated the unit had suffered 700 days of shutdowns since it opened. The unit was subsequently down for at least another 293 days, according to data from the UCA. 

Adding in the last year offline and Comanche 3 has been out of service about a quarter of its 16-year life.

In August, the PUC granted Xcel Energy a $157 million electric rate increase, about $5 a month on the average residential bill, and that included penalties for nonperformance of Comanche 3 of up to $30 million a year.

The UCA has filed a motion for the PUC to rehear and reconsider its decision in the electric rate case, arguing that Comanche 3’s annual revenue requirement — part of the  costs and investments upon which rates are based —- is roughly $110.6 million and subtracting the $30 million penalty leaves customers on the hook for about $79 million.

The UCA has proposed that Comanche 3 be removed from the rate base and customers only pay for it when it is operating.

The concerns over adequate generating resources the system faced this past summer haven’t eased, even with Comanche 3 coming online, Pereira said. 

In January, the PUC removed a cap on generation at Comanche 2 and Xcel Energy is seeking to extend the life of the unit for an additional year.

“Comanche 3 is up and running, but that doesn’t change the equation about whether we need Comanche 2,” Pereira said. “It looks like 2027 will be tight.”