Idaho Power files Fixed Cost Adjustment BOISE, Idaho (KIFI)-Idaho Power is asking the Idaho Public Utilities Commission to approve a $2.8 million fixed cost adjustment in its residential and general service rates. If the Fixed Cost Adjustment is approved, a typical residential customer using 950 kilowatt-hours per month would see about a $0.37 increase in their monthly bill beginning June 1. The full impact won't be known until the utility files its Power Cost Adjustment in April. Idaho Power estimates that would increase rates for both categories of customer by about .38%. The Fixed Cost Adjustment moves prices up or down based on actual charges in energy use per customer during the previous year.