The Colorado Public Utilities Commission said it will consider opening a docket to investigate the performance of Unit 3 of the Comanche coal-fired plant, one of the biggest greenhouse gas emitters in the state, which aims to eliminate carbon emissions from its power sector by midcentury. The investigation could lead to early retirement for the controversial facility, which began operation only 10 years ago.
The question of the fate of the unit arose during a May 13 hearing in which commissioners took up requests for rehearing, reargument and reconsideration of Xcel Energy Inc.'s rate case.
At issue was Xcel Energy's request for $11.7 million in investment costs to replace a malfunctioning superheater at the plant. The commission denied the utility's request and Xcel challenged that decision, saying it had remained under the construction cap.
Comanche 3, one of the newest coal-burning units in the nation, opened in 2010 despite bitter opposition from ratepayers and environmental advocates. It has had a history of problems that have resulted in unplanned outages.
Commissioner John Gavan said, "I think it's important to note that, at the end of the day, Comanche 3 is a real young 750-MW behemoth that's had too many operational problems."
"I remain very concerned about the ongoing performance and operational problems at Comanche 3," Gavan added. "I would like to open an investigatory docket on this issue to better understand the depth of these issues and to gain insight on the rate impacts that these ongoing operational problems have imposed on ratepayers."
Chairman Jeffrey Ackermann agreed. He said 2019 bills passed in Colorado that call for a transition to carbon-free power make the issue especially relevant. He said he would like to open an investigation into the constraints on the plant's performance, maintenance issues and the utility's investments in the plant.
Terry Bote, spokesman for the commission, said there will be a "full discussion on the scope and purpose of the investigation" at a future weekly meeting of the commission, likely in June.
"Based only on the comments at Wednesday's deliberations, the commission intends to consider the merits of opening an investigation into the history and continuing operations of Comanche 3, particularly as Colorado utilities consider measures for reducing emissions of carbon dioxide," Bote said in a May 19 email.
Leslie Glustrom, a board member of the Colorado nonprofit Clean Energy Action who has long opposed the plant, said regulators should shut down Comanche 3, which is currently slated to stay open until 2070.
"It's the wrong resource for the century," Glustrom said of coal.
Xcel, which operates as Public Service Co. of Colorado in the state, is planning to retire by 2025 the first two units at Comanche, totaling 660 MW, and add more than 2,000 MW of new wind, solar and battery storage, as well as new natural gas capacity.
Xcel owns 82.2% of the 1,426-MW plant, according to S&P Global Market Intelligence data. The Intermountain Rural Electric Association owns 13.4% and the Holy Cross Electric Association Inc. owns 4.2%. The plant uses coal from the Powder River Basin, in Wyoming.
Xcel Energy did not respond to a request for comment on the decision.