How about just closing Comanche 3 for good?

Environmental groups outline their views about what is best in wake of Colorado coal plant’s latest — and extended — outage.

by Allen Best

Comanche 3, the trouble-plagued coal-fired power plant in Pueblo, went down on Aug. 12. Xcel Energy, the unit’s operator and primary owner, says it can’t be restored to service until June 2026.

This will be the third extended outage since 2020 for the coal plant, Colorado’s largest and newest unit.

Might the best thing for Xcel’s customers be if the plant remained dormant? Don’t try to repair it, whatever is wrong this time. Instead, save the money and just continue operating the much older and more reliable — but soon to be retired — Comanche 2?

Several environmental groups have advanced that idea in response to a proposal by Xcel and three state agencies to keep Comanche 2 operating for a full year beyond its current planned retirement at the end of December.

That plan on the table would leave both coal-burning units operating in the second half of 2026, point out the Sierra Club and Natural Resources Defense Council. They would provide more power than needed and will also generate pollution at levels greater than acceptable.

Western Resource Advocates, the City of Boulder and others have similar things to say. They also embrace an alternative plan. That plan would have the state’s Public Utilities Commission give Comanche 3 a hard look in coming months instead of waiting until next summer.

“The question must be asked whether any further reliance on Comanche at this juncture is prudent,” says Boulder in its filing with the PUC yesterday. “Ratepayers continue to bear the consequences of (Xcel subsidiary) Public Service’s failings when it comes to Comanche 3. At some point, the bleeding must stop.”

In asking to keep the plant open, Xcel insists that it is vulnerable to having too little generating capacity. It is at risk of having resource inadequacy. The basics of any utility are to keep the lights on, with only rare outages. The environmental groups do not disagree, but they do question whether Xcel — in concert with a trio of state agencies — have over-stated the case.

Western Resource Advocates also questions what is causing the “resource adequacy” about which Xcel has been fretting.

“The proposed extension to the retirement of Comanche 2 and the unplanned, extended outage of Comanche 3 represent extreme circumstances that may result in tens of millions of dollars in unexpected cost and increased emissions above levels previously expected,” the Boulder-based WRA says in a filing with the PUC.

“Further, the proposed variance calls into question whether the company has strained its resource capacity position — at the expense of all existing customers — by soliciting and accepting new large-load interconnections.”

Large loads are commonly understood to consist mostly of data centers.

Pueblo County, along with the city and economic development group there, take a contrary point of view. They want to see the coal plants operating without question. They insist that the coal-fired power production from both units will be needed to power the steel mill in Pueblo. The plant is formally called Rocky Mountain Steel.

That’s partly accurate. However, the steel plant in 2023 went on-line with the Bighorn Solar Project, which has a capacity of 300 megawatts and can, on a net-basis, deliver almost all the electricity needed at the steel plant. The steel plant also operates when the sun does not shine, of course.

As part of their long-standing complaint, the Pueblo interests say that they badly need the coal jobs at Comanche. “Approximately one out of every four residents receive SNAP benefits compared to the state average of one in 10,” says Pueblo.

In 2018, Xcel and other parties at the negotiating table agreed that Comanche 2 would be retired by the end of 2025. The PUC commissioners stamped their approval on the agreement. That agreement assumed more or less steady operations of Comanche 3. The assumption was misguided.

Comanche 3 was down for an average 91 days each year during its first decade. Then came 2020, an outage that extended about a year and into 2021. Another outage soon followed. A 2021 PUC staff report found that the actual cost of energy from Comanche 3 had been nearly 50% higher than expected when the unit was proposed almost 20 years before.

The proposal has the backing of the Polis administration, including the Colorado Energy Office, the Office of the Utility Consumer Advocate, and the PUC trial staff. The petition with the PUC was filed Nov. 10 by Attorney General Phil Weiser.

The petitioners said that keeping Comanche 2 operating for a year was the “most cost-effective approach to providing needed electricity for the system” as identified by Xcel.

Given the outage of Comanche 3, say the environmental groups, they do not object to Comanche 2 remaining open for a year longer. They do, however, see problems with the proposal by Xcel.

First, the solution is “far broader than the problem it tries to solve,” says the Sierra Club and NRDC. If both Comanche 2 and 3 are operating, they will produce more power — and pollution — than had been planned.

They also point to a “glaring contraction” in the petition by Xcel and the state agencies. They see an imminent need to justify continued operation of Comanche 2 yet propose to delay starting a litigated proceeding at the PUC until next June to investigate all options for dealing with a near-term need.

This is getting the cart before the horse, they say. “Given the long history of forced outages at Comanche 3, its repeated cost overruns, and the fact that it is already slated to retire by 2031,” the PUC commissioners should weigh in before Xcel decides whether to repair Comanche 3.

The alternative plan advocated by the environmental community would keep Comanche 2 operating for a full year — but place limits on the operations of the unit coupled with that of Comanche 3, whenever it returns to service. “This allows the same total amount of generation from the two units as if Comanche 3 were available for all of 2026.”