Wyoming’s largest utility has officially joined a new “Extended Day Ahead Market” for electricity on the Western grid, a move that might just help lower rates as energy costs continue their skyward trajectory. Rocky Mountain Power, a subsidiary of PacifiCorp, along with other utilities and power producers across the West, now gets access to more buyers and sellers, allowing them to meet forecasted demand with electricity generated elsewhere. Because nothing says “energy independence” like buying your power from Nevada.
The new system runs on the network of the California Independent System Operator (CAISO), but will be overseen by an independent board of electricity experts from across the western U.S. - presumably to avoid any awkward California-Wyoming tension over who gets to set the thermostat. PacifiCorp began trading Thursday night after a period of simulations to fix bugs and assess how prices, demand, and supply interact. Thursday’s purchases were delivered Friday, according to CAISO and the company. PacifiCorp will be “the first participant alongside CAISO,” said Omar Granados, a spokesperson.
“We expect even greater reliability and affordability benefits for customers as the market grows,” said Elliot Mainzer, CAISO’s president and CEO, in a statement that sounds like it came straight from a PowerPoint titled “How to Make Everyone Happy (Eventually).” At a February hearing before Wyoming’s Public Service Commission, Michael Wilding, vice president of energy supply management at PacifiCorp, estimated that the company then satisfied about 3 to 5 percent of its generation and demand through broader market purchases. Under the day-ahead market, that number will be 100 percent. Revenue from sales and money saved will “be reflected in lower net power costs, which will flow through to our customers,” Wilding said.
Power bills have been rising across the U.S. for years, lately driven in part by electricity-hungry data centers that power AI - because apparently Skynet needs a lot of juice. In Wyoming, electricity bills rose by 5.5 percent from 2024 to 2025, according to Energy Information Administration data. Brian Turner, a senior director with Advanced Energy United, an energy trade association, said the new market will streamline power transactions in the West. Previously, Western utilities usually filled excess demand as needed from a handful of familiar power producers; there was no simple way to access a wider pool. “It allows for a lot more transparency, a lot more liquidity to the market,” Turner said. “There’s more buyers and sellers, and you can find your cheapest price.” So basically, it’s like eBay but for electrons.
PacifiCorp will participate as both buyer and seller - if it has cost-competitive power, it can sell; if it expects a spike in demand, it can shop around. Participation is voluntary, because nobody likes being forced into a marketplace. In Wyoming, the state’s Energy Authority will monitor PacifiCorp’s participation for its first five years, using data to track whether Wyoming’s coal, oil and gas sectors are being “unfairly penalized” by climate targets in California, Oregon and Washington, said John Jenks, the authority’s director of energy market development. Long one of the nation’s top fossil fuel producers, Wyoming has leapt at Trump administration directives to boost fossil fuels, a more expensive source of new generation than wind and solar. Jenks said the ability of fossil fuel plants to ramp up generation regardless of weather made him “optimistic that Wyoming will continue to be an important player in reliability.” Because nothing says reliable like burning ancient carbon.
“For a state like Wyoming, energy policy is our lifeblood,” Jenks said. “We just want to make sure that whatever’s happening is not going to adversely affect our economic development goals.” The new market comes as energy prices skyrocket due to the war in Iran, and it may help insulate consumers from such economic shocks, Turner said. Since the U.S. and Israel first struck Iran in March, the cost of oil has spiked, pushing up prices at the gas pump and reverberating through other sectors. “When the price for natural gas goes up, [utilities] still got to meet their demand with those generators, and so they’ve got to pay that price. And then they’ve got to pass that on to ratepayers,” Turner said. “But if they had a big market where, say, solar energy from Nevada or Idaho or Arizona is very cheap, … Wyoming can import that instead of having to pay whatever the high natural gas price is at any given time.” It is unlikely such a market mechanism would fully exempt Western power consumers from price shocks emanating from the Middle East, but hey, you can’t win ’em all.
The Extended Day Ahead Market is the first such market in the West. The regional transmission organization Southwest Power Pool is creating another marketplace, initially with power producers in Arizona, Colorado and the Northwest. So if you’re keeping score, the West is now a trading floor for electricity, and Wyoming is cautiously optimistic it won’t get screwed over by those coastal elites.