⚖ Oral Arguments, with Context

The Tenth Circuit hears a dispute over Wyoming electricity rates for PacifiCorp, known there as Rocky Mountain Power. The utility asked state regulators to raise rates and used a forecast of its future power costs to support the request. That forecast included generating capacity held in reserve for federally regulated transmission service; those reserves cannot simply be sold as surplus electricity. A group of large industrial customers challenged how much of that reserve cost Wyoming customers should bear. The state commission adopted their adjustment, reducing the Wyoming share of forecast power costs by about twenty-three and a half million dollars. PacifiCorp sued, arguing that the adjustment effectively treated federally required reserves as power available for sale and conflicted with federal regulation. A federal judge agreed and barred the commission from using that reasoning to set rates. The commission and industrial customers appeal, saying the adjustment corrected an overestimate without removing federally required reserves. They also contend that a newer rate order makes the dispute moot, meaning a decision would no longer change their rights. PacifiCorp says the newer order carries forward the same disputed cost figure.

PacifiCorp v. Wyoming Industrial Energy Consumers (No. 25-8061) — U.S. Court of Appeals for the Tenth Circuit, argued September 15, 2026.