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Rocky Mountain Power To Retrofit A Coal Plant With Carbon Capture, A High Cost For Taxpayers



April 1, 2024 - Rocky Mountain Power, the largest utility company in Wyoming, announced it is planning to retrofit one of its coal-fired power plants in the state with carbon capture technology. It has also announced on Friday that it will be working with 8 Rivers to explore its revolutionary oxy-combustion of carbon fuels process for the capture of the emissions of the coal plant. 

The partnership also includes support from South Korea’s SK Group, a conglomerate of global tech innovation companies. Rocky Mountain Power will first choose one of two coal-fired plants to retrofit with the technology. It will have to determine whether to install carbon capture on the Wyodak coal-fired power plant near Gillette or the Dave Johnston coal plant outside Glenrock. 

Both of these plants have been announced for retirement. In September 2021, PacifiCorp, owner of Rocky Mountain Power, listed Wyodak’s coal unit to retire in 2039 under its Integrated Resource Plan’s preferred portfolio. According to the company’s 2023 Integrated Resource Plan, unit 4 of the Dave Johnston coal-fired plant is planned for retirement in 2039 while units 1 and 2 are expected to close in 2028. 

Once a site has been selected, the partners will “conduct feasibility evaluations, which might advance to various phases of engineering and design studies.” After studies are conducted, Rocky Mountain Power and its partners will make a final decision whether to move forward with construction.

The “upfront” costs for the engineering design and feasibility analysis are expected to exceed $10 million, according to some estimates, however, according to the company, ratepayers will not cover them. 

The construction costs though that could range from $500 million to beyond $1 billion for each of the coal-burning units are subject to Wyoming’s mandate, according to preliminary estimates the utilities filed with the state in 2023. There is the possibility that the utilities’ ratepayers will cover those construction costs, or the big chunk of the total expenses.

The costs of retrofitting carbon capture technologies on coal-fired plants are competitive to non-fossil fuel alternatives. 

Rocky Mountain’s plan is part of Wyoming’s efforts to force utilities to retrofit the state’s coal plants with carbon capture in order to expend the operating life of the plants. The state has passed bills to mandate carbon capture retrofits at coal plants and sell the captured CO2 for industrial uses such as enhanced oil recovery. The U.S. government has also introduced the 45Q incentive tax credit that provides $60 for a tonne of CO2 captured and used, including for enhanced oil recovery.

In Wyoming, ratepayers are eligible to pay for both the cost of analyzing the feasibility of retrofitting coal plants with CCS and the cost of construction and operation. That will come in addition to the already increasing energy bills for Rocky Mountain customers who saw 8.3% raise beginning Jan. 1.