Wyoming coal will play a shrinking role in PacifiCorp’s energy supply portfolio as the utility adds more wind and solar power and either retires or converts its coal-fired power units in the state to natural gas.
Only two of the utility’s 11 coal-fired power units currently operating in the state will continue burning coal beyond 2030 — Wyodak near Gillette and Unit 4 at the Dave Johnston plant in Glenrock — according to the utility’s biennial Integrated Resource Plan filed on Friday. Several coal units will be spared from earlier decommissioning plans and instead be converted to natural gas — Jim Bridger units 3 and 4 in 2030 and Naughton units 1 and 2 in 2026.
Dave Johnston Unit 3 will be retired in 2027, and units 1 and 2 will be retired in 2028 rather than 2027.
All told, PacifiCorp will cut its coal-fired power generation capacity across its six-state operating region by 1,153 megawatts by 2026 and 3,000 megawatts by 2032, and replace it with wind and solar energy, battery storage, nuclear power, wholesale power purchases and energy efficiencies, according to the company, which operates as Rocky Mountain Power in Wyoming.
“Our Integrated Resource Plan is designed to determine the lowest-cost options for customers, adjusting for risks, future customer needs, system reliability, market projections and changing technology,” said Rick Link, who serves as PacifiCorp senior vice president of resource planning, procurement and optimization.
No carbon capture for coal
One option that doesn’t fit those parameters is retrofitting decades-old coal-fired power units with carbon capture, use and sequestration technologies. PacifiCorp also filed a mandatory report to the Wyoming Public Service Commission Friday to update officials on its call for bidders to possibly install CCUS facilities at its coal units in the state — an action mandated by Wyoming law.
“Through 2042, the [analysis] for all CCUS variants result in higher costs than the preferred portfolio,” PacifiCorp said in its 48-page report. The summary suggests it will cost Wyoming ratepayers “$514 million [to retrofit] Dave Johnston Unit 2, $857 million for Dave Johnston Unit 4, and $1.3 billion for Jim Bridger units 3 and 4.”
Of the 54 companies that PacifiCorp sought bids from, only 21 qualified and only three participated in mandatory site visits, PacifiCorp said. The bidding and analysis also confirmed that adding CCUS to an existing coal-fired power unit drastically reduces a facility’s generation capacity, which would require replacing that lost capacity.
PacifiCorp is still working with vendors to explore the potential for taking on CCUS retrofits, however.
“The company has determined that Dave Johnston Unit 4 and Jim Bridger units 3 and 4 remain potentially suitable candidates for CCUS and are being further analyzed under the company’s RFP process approved by the [Wyoming Public Service Commission] in the initial application,” PacifiCorp said in its report.
CCUS retrofits remain a significant cost and power-delivery-reliability risk for Wyoming ratepayers, Powder River Basin Resource Council Chairman David Romtvedt said.
“Ratepayers should not be asked to cover the costs of uneconomical energy projects,” Romtvedt said in a prepared statement. “Instead, we support the addition of cost effective and environmentally responsible renewable energy sources to the company’s overall energy profile.”
Renewable shift and potential nuclear
PacifiCorp’s updated Integrated Resource Plan, which looks ahead 20 years, includes quadrupling its wind and solar resources to 20,000 megawatts by 2032, backed with an additional 7,400 megawatts of energy storage.
The utility still envisions taking ownership of TerraPower’s Natrium nuclear energy facility at Kemmerer — which is expected to begin operating in 2030 — and possibly taking on two more small modular reactors co-located at coal plants in Utah.
The expansion of renewable and low-carbon electric generation facilities is accompanied by approximately 2,500 miles of new transmission lines, many of which will connect Wyoming renewable sources to PacifiCorp service territories in the West. All told, the power shift and transmission buildout should result “in a system-wide 70% reduction of greenhouse gas emissions from 2005 levels by 2030, an 87% reduction by 2035 and a 100% reduction by 2050,” PacifiCorp reported.
Paramount to those greenhouse gas emission savings is curbing the utility’s reliance on coal.
“Driven in part by ongoing cost pressures on existing coal-fired facilities and dropping costs for new resource alternatives, of the 22 coal units currently serving PacifiCorp customers, the preferred portfolio includes retirement or gas conversion of 13 units by 2030 and 20 units by year-end 2032,” PacifiCorp said.
Though it remains to be seen how PacifiCorp’s shift away from coal and toward a lower-carbon energy portfolio will affect jobs and revenue in the state, the company’s plan acknowledges a larger energy industry shift and opportunities for the state, according to Romtvedt.
“Greater use of renewable energy will help us to ease the dislocation caused by the transition away from extractive resources while developing a more sustainable energy future that can support stable economies in our communities,” he said.