Extreme weather events prompt increase for Wyoming electric customers

CASPER, Wyoming — Rocky Mountain Power has requested the Wyoming Public Service Commission review and approve a surcharge on customer bills of 7.6% on average, or $50.3 million overall, based on increased fuel costs and power purchased on the wholesale market during 2022. If approved, the average residential customer using 660 kilowatt-hours per month will see an increase of approximately $3.52 on their monthly bill.

Rocky Mountain Power asked the change take effect July 1, 2023, subject to a later true-up based on the commission’s analysis and final decision. The change would appear as a separate line item on customer bills. The effect on individual rate classes varies:

Customer rate schedule

Increase percentage

Residential – 2, 19


General service – 25


General service – 28, 29


General service – 46


General large transmission – 48T


Agricultural pumping – 40


Agricultural pumping – 210


“We recognize how difficult cost increases are for our customers. Unfortunately, market forces have impacted our costs to continue providing safe, reliable electric service to our customers. These types of impacts are being seen across all utility companies, including Rocky Mountain Power,” said Sharon Fain, Rocky Mountain Power’s Vice President for Wyoming. “Despite these market changes, our rates remain among some of the lowest in the country and we’re working hard to maintain that position and value for our customers.”

This annual cost adjustment includes the variable costs of providing electric service, such as fuel and wholesale electricity purchases. These costs fluctuate every year, so the annual cost adjustment is used to account for changes during the previous year. This can result in either an increase or a decrease to customer bills.

Extreme weather events and drought conditions persisted in the West during 2022 and continued to have significant impacts on wholesale power prices. Multiple heat waves across the company’s service area throughout July, August and September 2022 led to price increases in wholesale power purchases. 

Rocky Mountain Power provides approximately 95% of the power it supplies to customers from power plants it owns, and from long-term power purchase contracts. To balance its transmission system and to take advantage of reasonably priced market power, the company purchases the remaining 5% from other utilities. These prices fluctuate in the competitive wholesale market. Additionally, any revenues the company makes from power sales to wholesale buyers are credited back to customers as part of the annual cost adjustment. 

“Sharply higher prices in the wholesale power market during the severe summer weather of 2022 are responsible for nearly half of Wyoming’s share of increased power costs,” said Jack Painter, Net Power Cost Specialist. “Natural gas prices continued to be affected by weather events and supply issues. In December 2022 a historic winter cyclone impacted much of the country, prompting increased customer demand and leading to higher prices in both wholesale power and natural gas markets. Natural gas prices across regional delivery points drastically increased. At major natural gas trading hubs, average prices were more than 400% higher in December 2022 compared to December 2021. These factors doubled the costs of generating power from the company’s natural gas power plants,” Painter said.

“We work diligently to provide safe, reliable electric service at reasonable prices and to control costs when and where possible,” Fain said. “These annual energy cost adjustments track costs beyond the company’s direct control and factor in 2022 investments made by the company to ensure reliable service to customers. This annual energy cost adjustment mechanism ensures our customers do not overpay or underpay for the electricity they use.”

For customers who may need assistance with their power bill, help is available. Rocky Mountain Power customer service representatives have information on assistance programs for customers who qualify. Call us at 1-888-221-7070, or visit RockyMountainPower.net/Assistance. Make sure to select the state in which you live, as programs vary by state.

For customers wanting to provide help, you can donate through Energy Share of Wyoming to help members of your community facing financial difficulties paying their energy bills. Customers can also help a family member or friend by making a payment to directly to their Rocky Mountain Power account. You choose whatever amount you'd like to pay, either with your online account or by mail. The bill payment assistance link has details online.