Smoke stacks at three of the four Jim Bridger Plant coal-fired electrical generating units. (Angus M. Thuermer, Jr./WyoFile)

Adding carbon-capture systems to existing coal-fired power plants in Wyoming could cost the average residential ratepayer an additional $100 per month, according to Black Hills Corp’s initial filings to the Wyoming Public Service Commission.

The retrofit costs alone could range from $400 million to $1 billion for each coal unit, according to PacifiCorp, which operates as Rocky Mountain Power in Wyoming. Adding carbon capture utilization and storage technologies would also significantly reduce electrical generation efficiency at the coal plants, further ramping up the expense for ratepayers. Generation efficiency could be reduced 14%-35% at Wygen II and Neil Simpson II near Gillette, according to Black Hills Corp.

Both PacifiCorp and Black Hills Corp are moving forward with feasibility studies to further analyze whether it is viable to apply CCUS at five coal-fired power units in Wyoming.

State mandate

The studies stem from a 2020 legislative mandate written into House Bill 200 –  Reliable and dispatchable low-carbon energy standards. Now law, the Wyoming PSC is wrestling with how to administer what some refer to as a coal-CCUS portfolio standard — the only such portfolio standard in the nation. It requires regulated utilities to determine how much CO2 capture can be applied to existing coal plants and still justify the costs to ratepayers. One preliminary conclusion by PacifiCorp and its consultant Kiewit Engineering Group, Inc. suggests that capturing 40% or more CO2 emissions would not prove economic for coal units included in its analysis. 

PacifiCorp’s Dave Johnston coal-fired power plant just outside Glenrock. (Dustin Bleizeffer/WyoFile)

Lawmakers who supported HB 200 hoped a large price tag for adding CCUS might be justified when also factoring new jobs and revenue from selling the CO2 that’s captured from coal plants. The sold product could be utilized to produce untapped oil reserves and potentially create new CO2 byproducts. However, regulated utilities typically cannot include factors outside their scope of services in a request for ratepayer increases, such as tertiary oil production or the value of potential CO2 byproducts.

House Bill 200 proponents also sought to minimize the ratepayer burden by allowing the PSC to establish a cap for incremental rate increases. The commission in November set a 2% cap, potentially preventing something on the order of a $100-per-month increase. But regulated utilities must be allowed to charge ratepayers for full capital and implementation costs, which could result in extending the period that a utility charges ratepayers for a CCUS investment — potentially by decades. 

PacifiCorp estimates the 2% cap could generate a maximum $13.1 million annually for a CCUS project that costs between $400 million and $1 billion. 

“That means, presumably, you’d have to run [some coal units] for another 50 years,” Powder River Basin Resource Council attorney Shannon Anderson said. “If that doesn’t happen, then at some point ratepayers are going to be paying for systems that we are no longer using.”

Unanswered questions

State regulators are still wrestling with many questions and assumptions regarding the coal-CCUS feasibility mandate, PSC Chief Counsel John Burbridge said.

“There certainly is a lot of discussion about the cost of installing CCUS on currently operating coal units,” Burbridge said, adding that the new statutes stemming from HB 200 allow a utility to forego installing CCUS on a coal plant if it can prove to the commission it is not viable for ratepayers. “If they can show that, and convince the commissioners that this just isn’t economic for the customers, then I think it just kind of dies a slow death.”

Another result is that Wyoming ratepayers alone would likely shoulder the cost, Anderson said. 

“It just doesn’t make sense when wind and solar are right there and so much cheaper.”

Shannon Anderson, Powder River Basin Resource Council

PacifiCorp serves customers in six western states, including Wyoming. Typically, all six states negotiate to divide the cost of PacifiCorp’s capital investments based on each state’s reliance on a particular facility. However, states like Oregon and Washington may decline to take on power from a Wyoming-mandated coal-CCUS investment.

That could change if there were a federal carbon capture standard, but observers don’t anticipate that happening anytime soon.

“It just doesn’t make sense unless there’s some environmental mandate from [the Environmental Protection Agency] or Congress or somebody,” Anderson said. “It just doesn’t make sense when wind and solar are right there and so much cheaper.

“These filings are the first real numbers we’ve seen on what carbon capture means to the average consumer in Wyoming,” Anderson continued. “These are incredible penalties, really.”

Although it’s made no final determination and is still collecting third-party analysis for a complete CCUS feasibility study, PacifiCorp is asking the Wyoming PSC to approve a 0.5% surcharge to all its Wyoming customers to help pay for the mandated studies — which are already in motion — as well as implementation costs if the utility moves forward with a CCUS retrofit.

If approved, the new surcharge would generate $3.1 million in revenue from PacifiCorp’s Wyoming customers annually. The same surcharge — if extended to the 2% cap — could generate up to $13.1 million annually if it and the PSC eventually greenlight a CCUS retrofit, according to PacifiCorp filings.

A public comment period regarding PacifiCorp’s request [Docket No. 20000-616-EA-22] for the 0.5% surcharge ends on April 22. Public comments can be sent to

Dustin Bleizeffer is a Report for America Corps member covering energy and climate at WyoFile. He has worked as a coal miner, an oilfield mechanic, and for 25 years as a statewide reporter and editor primarily...

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  1. The last coal fired locomotive was built in North America in 1953. By 1960 no coal train in this country ever again trundled from coalfield to powerplant powered by the antiquated and filthy fuel that it contained. It is long past time to apply the same forward thinking to electrical generation. The most efficient way to sequester carbon is to simply leave the dirty little rocks buried in the earth where they belong.

  2. It will only cost everybody in the state $100 a month to save the buggy whip manufacturers? What a deal!

  3. Forty nine other state legislatures and the Federal government felt this was an ineffective approach. Wishful thinking on the CO2 sales. Please continue this excellent level of financial analyses.

  4. Excellent article. Please allow me to clarify two points: First, the efficiency penalty at Black Hills power plants is not between 14% and 35%, it is 36% for WYGEN II (and 37.4% for Neil Simpson I). The 14% figure is the amount of steam diverted from the main boiler to the CCUS unit and therefore unavailable for power production. On top of that loss, the increased parasitic load from CCUS raises the overall efficiency penalty to 36%. Second, the statement, “capturing 40% or more CO2 emissions would not prove economic for coal units included in its analysis” wrongly implies that less than 40% would be economical. In fact, the maximum portfolio percentage Black Hills Power could retrofit at ANY cost is 35% because much of their generation capacity is not wholly owned and therefore not eligible for CCUS. But any CCUS conversion would be uneconomical. Their report shows that even a 20% portfolio standard would cost over $360 million in capital and $11.7 million in annual operating costs. The 2% surcharge of $3.85 million per year wouldn’t even cover a third of the annual operating costs, much less recover the capital investment. Black Hills states that the most economically feasible solution to a low-carbon standard would be converting the boilers from coal to natural gas, at only 5% of the cost of CCUS.

  5. I already pay 153.00 a month for electricity and that’s a supposed discount for equal pay. I couldn’t afford another 100 a month. That’s just fecking ridiculous. Give me a break Rocky Mtn Power. I have a single wide trailer and use gas for heat.

  6. I propose that Pacific Corp and it’s stockholders ought to pay for any investment into their privately held company or restructure so that the ratepayers become qualified for dividend stockholders and voting stock owners, otherwise, the company can go suck eggs!!!

  7. And we shouldn’t have to pay for more studies when the obvious conclusions are already known. It was a legislative mistake, built with wishful thinking.
    The only question worth study is: now how do we get rid of that ridiculous HB 200?

  8. So the utility companies are finally admitting what they’ve known for years- clean coal is a unicorn.

  9. The legislature really knows how to plan for the future. I hope they remember what happened to the dinosaurs…

  10. Why not just levy a tax of about $100 per household and give it directly to the coal companies? It would accomplish the same thing without wasting a lot of effort that would be better used to build renewable infrastructure.

    1. Similar things have been done, and more often than not the companies just keep the money with no repercussions. Telecom companies have received billions upon billions of direct funding for infrastructure, and just kept it.

    2. The company is asking for $1200/ year from each and every family living in Wyoming, and no end date. If they want to do this, the ratepayers ought to get stock that is voting and gets dividends from Pacific Corp…