OREANDA-NEWS. Utility Idaho Power is resisting efforts to prematurely retire the 522MW North Valmy coal-fired power plant in Nevada it co-owns with NV Energy.

The Idaho utility's proposed integrated resource plan calls for keeping North Valmy on line through 2025, which marks the 40-year life span of the second, newer unit at the power plant. The plan is superior to numerous other alternatives considered by Idaho Power, including retirement of North Valmy in 2021 or earlier, the Idaho utility told the state Public Utility Commission.

The retirement of North Valmy should coincide with completion of the Boardman-to-Hemingway transmission line, which could transport 1,050MW between central Oregon and southeast Idaho. Keeping the coal plant on line through 2025 balances the risks of the Environmental Protection Agency's Clean Power Plan, increases in unplanned renewable generation and is cost-competitive, Idaho Power said.

The Idaho utility owns 50pc of North Valmy, located well outside of its service territory. NV Energy owns the other 50pc and operates the power plant. NV Energy wants to retire the 254MW unit 1 at North Valmy plant in 2021 and the 268MW unit 2 in 2025 in part to comply with Nevada laws calling for reducing stakes in coal-fired generation. So the two utilities must reconcile their plans.

NV Energy was not immediately available to comment.

Divestment mandates in the western states have reduced the value of coal-fired generation at power plants owned by multiple parties. The Los Angeles Department of Water and Power recently agreed to sell its 477MW of capacity at the Navajo coal plant in Arizona to utility Salt River Project for only $10mn.

Idaho Power owns 1,118MW of coal-fired capacity, including stakes at North Valmy, the 2,119MW Jim Bridger plant in Wyoming and the 585MW Boardman in Oregon. PacifiCorp-operated Bridger has no immediate plans to retire but Portland General Electric plans to shut Boardman in 2020.

Coal last year accounted for 31pc of Idaho Power's installed capacity and 34pc of generation.

North Valmy last year operated in January-March only, Energy Information Administration data show. The plant in the first quarter of 2015 burned 193,964 short tons (175,533 metric tonnes) of sub-bituminous coal. Receipts in the same period totaled 229,381st from the Black Butte, Leucite Hills, North Antelope Rochelle, Antelope and Black Thunder mines in Wyoming.