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PacifiCorp extends the life of Utah coal-powered plants — indefinitely

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PacifiCorp extends the life of Utah coal-powered plants — indefinitely

By Alixel Cabrera
PacifiCorp extends the life of Utah coal-powered plants — indefinitely
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Coal is stored outside the Hunter coal-fired power plant, operated by PacifiCorp, in Emery County on Wednesday, July 31, 2024. (Photo by Spenser Heaps for Utah News Dispatch)

In past iterations of a long-term regional resource plan from PacifiCorp, Rocky Mountain Power’s parent company, there have been estimated timelines to shut down Hunter and Huntington, two major Utah coal-powered power plants. But, the last update of the draft doesn’t foresee a closure in the next 20 years.

In the 2023 version of PacifiCorp’s Integrated Resource Plan (IRP), coal units at Hunter had an assumed end in 2042, while Huntington units were scheduled to be retired in 2036. In this year’s plan, PacifiCorp assumes both plants, located in Emery County, won’t be retired anytime before 2045. 

“The reason for that is, primarily, the changes that have happened recently in regulatory requirements at the state and federal levels,” David Eskelsen, a Rocky Mountain Power spokesperson, said about the lack of retirement dates for Hunter and Huntington. 

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However, that doesn’t mean they will operate at full capacity. 

Actually, the utility is expecting to ramp down its coal burning at the same time it decreases its investments in some cleaner energy resources, including solar, wind and storage. 

Last year, the Republican supermajority at the Utah Legislature approved a series of bills that prevented what was described as the premature retirement of coal units in the state, and prioritized the production of dispatchable resources — which most often come from fossil fuels.

This year, legislative leaders intend to continue that work while also keeping an eye on what Rocky Mountain Power is charging, after the company proposed an 18.1% rate increase for residential bills.

Rep. Colin Jack, R-St George, who ran some of the most substantial energy bills last legislative session, commended PacifiCorp’s coal plants, saying they are robust and resilient, and with proper maintenance and overhauls, they can last for the foreseeable future.

Based on conversations Jack has held with Rocky Mountain Power, he said he’s appreciative of this plan.

“This iteration of their integrated resource plan is more based on realities of the power system,” he said, “and less so on political aspirations from their West Coast states.”

A train car carrying coal
A Union Pacific train transports coal through Spanish Fork Canyon in Utah County on Wednesday, July 31, 2024. (Photo by Spenser Heaps for Utah News Dispatch)

Coal plants may be kept online, but are at lower capacity

While currently the utility is expecting to keep coal burning in Utah through the next two decades, anything could change in that timeframe, since these plans get refreshed every two years. This is a first draft of the plan set to be reviewed by the company’s stakeholders before being filed to utility commissions in the states where PacifiCorp operates around March 31.

Built in the late ’70s and early ’80s, Hunter and Huntington are among the newest coal-fueled units in the PacifiCorp network. But that’s not the main reason why retirement dates were removed from the current plan.

Apart from federal and state regulatory requirements, PacifiCorp also substantially changed the way it operates those coal units in the last few years, Eskelsen said. Other utilities in the west produce plenty of renewable energy, making its price “extremely low,” according to Eskelsen, and PacifiCorp takes advantage of those offers on a daily basis.

“So what we do with our coal plants, rather than running them at a steady level all the time, which is what we used to do, we ramp them down in their output,” Eskelsen said. “We don’t turn them off. We ramp them down to a very low level, and keep them on standby.”

Then, during the late afternoon, when solar energy starts to fall off, PacifiCorp cranks up its coal and natural gas units to fill the gaps. 

That has been the practice for the last several years, Jack said. 

“We have learned through necessity that you can actually keep them running down to about half of its capacity,” Jack said, “which allows you to take advantage of market opportunities when you have places in neighboring states like California, who have over-built, by significant margin, the amount of solar that they can absorb.”

Essentially, that production excess, Jack said, pays for power plants in Utah to back down. 

But, he doesn’t believe PacifiCorp will be operating its coal plants at less than 50% of their capacity since such low numbers may cause the units to trip off, potentially taking at least a day to get them working again.

Less solar and wind investment

When Logan Mitchell, climate scientist and energy analyst at Utah Clean Energy, first read PacifiCorp’s plan, he didn’t give much importance to the lack of retirement dates for the Emery County coal plants. 

“I just don’t think it’s going to be realistic, because coal is expensive, it’s dirty, it’s polluting. These plants are, like, 50 years old now.” Keeping them online past 2042 and 2036 “is going to be wildly expensive,” he added. “I don’t think anyone’s going to stand for it.”

What he was looking at, instead, were the investments of substantially cleaner solar and wind sources. Taking out projects that are already under contract — which includes the massive solar-powered Green River Energy Center — the company expects to add basically no more solar resources for Utah until 2032. 

Wind resources are facing a similar scenario, a step back from what PacifiCorp proposed in its 2024 update, which estimated a 4.5 gigawatt bump during the late 2020s, Mitchell said.

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“Now we’re not going to have any wind until there’s a tiny little sliver in 2028 and 2029,” he said, “and then we do get up to two gigawatts, just really not that much.”

Regarding energy storage, the 2025 draft scaled back from 2023’s plan, which called for building the capacity for about eight gigawatts of batteries. Now it will take about a decade to get two gigawatts of storage. 

The biggest factor driving the portfolio were certain settlements on federal and state environmental requirements, Eskelsen said, mostly with the Clean Air Act’s Regional Haze standards, which has been heavily challenged in different states, including Utah.

“We implement the policies of the states we serve and those articulated by the federal government, and we comply with those,” Eskelsen said. “But until that process is completed, we can’t really make the investment until we understand what the requirement is going to be.” 

However, he highlighted that PacifiCorp’s planning indicates that 6.3 gigawatts of new wind power resources are going to be needed by the end of 2045, in addition to 7.6 gigawatts of storage.

“So there are plenty of advancements and investment in those renewable resources, both wind, solar and storage in this plan,” Eskelsen said.