In the Matter of the Commission’s Investigation Pursuant to Wyoming Stat. § 37-2-117 of the Integrated Resource Plan Filed by Rocky Mountain Power on October 18, 2019

Rocky Mountain Power (RMP), a division of PacifiCorp, was a public utility that provided electric service in Wyoming. RMP filed integrated resource plans (IRPs) with the Wyoming Public Service Commission (the commission) every two years. The IRP identified the portfolio of electricity generation and transmission resources that RMP would provide in Wyoming. In April 2018, the Oregon Public Utility Commission ordered PacifiCorp to perform a limited coal-system-optimization study (the coal study) on PacifiCorp’s coal-fired generation units. The coal study indicated that 16 coal-fired units should be closed. In October 2019, RMP filed an IRP that contained proposals and assumptions about the early retirement of coal-fired resources based on the coal study’s conclusions. Specifically, the IRP proposed replacing 4,500 megawatts of coal-fired power generation in Wyoming with 6,300 megawatts of solar resources, 4,600 megawatts of new wind resources, 2,800 megawatts of battery storage, and other energy-efficiency increases. Given the importance of the coal study to the proposals in the IRP and the proposed massive transformation in energy generation, the commission initiated an investigation of the coal study and the IRP. Commission staff noted deficiencies in the IRP, including that (1) the IRP did not fully analyze whether the negative impacts to Wyoming communities from prematurely retiring coal-fired power-generation units outweighed the benefits of the IRP’s proposed resource portfolio, (2) RMP made speculative carbon-cost assumptions underlying its estimate of the future operating costs of coal-fired power-generation units, and (3) RMP failed to analyze carbon-capture technologies in the IRP. The commission heard testimony from local-government witnesses about the significant negative social and economic impacts that prematurely closing coal-fired generation facilities would have on the facilities’ employees and their communities. The commission also heard testimony from a county commissioner that RMP had not proposed an adequate way to mitigate the economic loss. The commission issued a report on the IRP following the investigation.