We’re moving as fast as we possibly can, says Colorado’s second largest electrical utility in filings with state regulators
by Allen Best
Colorado’s second largest electrical utility has committed to 80% reduction in carbon emissions by 2030 as compared to 2005. But can it cut even deeper, faster?
Filings with the Colorado Public Utilities Commission in late September offer a peek into the thinking of both that utility, Tri-State Generation & Transmission, and various other groups at the table.
“It is not reasonable to construct and integrate the sheer quantity of modeled new resources under this scenario,” says Tri-State in a filing submitted on Sept. 28. “The extent of the resources called for in eastern Colorado and Wyoming before 2028 are not physically possible on Tri-State’s transmission system.”
Tri-State was responding to a scenario called Roadmap, which calls for early retirement of 800 megawatts of coal generation—including the final unit at the Craig Generation Station in Colorado by 2028, ahead of Tri-State’s current plans of New Year’s Eve 2029.
That same Roadmap scenario would also have Tri-State curtail its use of a coal-fired power plant in Arizona called Springerville, cutting off production from the plant altogether in 2028 and also idling its share of Wyoming’s Laramie River Station coal plant for three to five months at a time.
Tri-State supplies electricity to 18 of Colorado’s 22 electrical cooperatives as well as 24 others in New Mexico, Wyoming, and Nebraska. Unlike Colorado’s two investor-owned electrical utilities, Xcel Energy and Black Hills, it had not been required to submit electric resource plans to the state regulatory body until a 2019 state law said it must.
In practice, Tri-State operated much like the private companies even if it is a non-profit cooperative, a creation of its member cooperatives. Individual cooperatives as well as municipal utilities still are not required to submit such plans.
In this inaugural voyage under the 2019 law, Tri-State submitted its electric resource plan in December 2020. Tri-State promises 80% reduction in carbon dioxide emissions by 2030 as compared to 2005 (and 70% renewables). Xcel, the state’s largest utility, says it can achieve an 85% reduction (and 80% renewables).
Tri-State sees its path forward including more than 2,000 megawatts of new renewables, both wind and solar, as well as energy storage, by 2030.
Stakeholders have alternative ideas about how Tri-State should move forward, most calling for a more rapid retreat from coal. Their proposed scenarios have been modeled by Tri-State with aid of its new modeling software developed for utility planning.
Those stakeholders—who didn’t necessarily agree with each other in all cases—consist of the Colorado Energy Office, Colorado Independent Energy Association; the staff of the PUC; the Conservation Coalition (including Sierra Club and Natural Resource Defense Council); the International Brotherhood of Electrical Workers Local 111; Interwest Energy Alliance; Southwest Energy Efficiency Project; Western Resource Advocates; and Wyoming Rural Electric Cooperatives.
One of the disagreements involves the schedule for closing the units at Craig. Tri-State plans to close the first unit by the end of 2025, the second unit in September 2028, and then the third unit on New Year’s Eve 2029. It proposes to operate the coal units at lower levels during the latter part of the decade as it brings on renewables.
Three of the six alternative scenarios would have the final unit at Craig closed by the end of 2025.
Disagreements are also found in the sequence for closing the Arizona coal plant, Springerville. Tri-State has a contract through 2036 to lease 100% of the power generated by a 420-megawatt unit at the coal plant. Tri-State says it would be costly to escape that commitment quickly, although the details are blacked out in the public version of the filing.
Another point of contention is Laramie River Station in Wyoming. Tri-State is a partial owner as a result of its ownership in the Missouri River Power Project but has not had discussions with its partners. “Therefore, the costs are assumed to be immitigable in the modeling,” Tri-State says, using a word that means unable to be made less severe or serious.
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In general, Tri-State wants to go slower in shifting off its coal plants. To go quicker means adding more natural-gas fired generation more rapidly, and the time for permitting such plants remains an unknown.
Several times, Tri-State says it wants to give time for other technologies to become more competitive. In other words, don’t rush the solutions. At least in its rebuttal document filed on Sept. 28, it does not describe those other technologies. It is known to be interested in both hydrogen storage and advanced nuclear technology—as, for that matter, most other utilities also are.
The filing also contains information about how it intends to assist the Craig community as it exits coal. The filings also emphasize the importance of a regional transportation organization, or RTO, in decarbonizing electricity while ensuring reliability and lower costs.
A separate statement posted by Tri-State on its website notes that Tri-State is actually lowering rates, with a 2% reduction in March to be followed by another 2% in 2022.
Eric Frankowski, executive director of the Western Clean Energy Campaign, a group premised in a more rapid retreat from fossil fuels by utilities, found the latest filing by Tri-State to be lacking critical information. “Where is the explanation for why they want to operate Craig (unit 3) until 2029 while the modeling shows it would be better for customers to operate until only 2025. I don’t see that explanation in there.”
Also absent is any exploration of what it would take to close the coal plants in Arizona and Wyoming.
“With the exception of some new gas being delayed, (Tri-State’s revised preferred alternative) doesn’t do a whole lot to move the needle on retiring coal early and getting customers away from one of its most expensive generating sources.”
The other stakeholders have until November to respond to Tri-State’s latest filing. This is the way of the long, drawn-out process for creating the electrical grid of the future.
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