Montana Utility Cost Calculator

NorthWestern Energy and the co-ops

NorthWestern Energy sold 2.8 TWh to Montana homes in 2024 — about half of all residential electricity — under the Montana Public Service Commission, which also oversees Montana-Dakota Utilities. Twenty-nine cooperatives made 30% of retail sales, the seventh-largest co-op share in the country, with about 227,000 accounts; Flathead Electric is the largest. Mission Valley Power, operated by the federal Bureau of Indian Affairs, appears among the top five retailers. Energy-only suppliers delivered 20% of all retail sales, to only a few hundred accounts.

Coal, water and wind

Montana generates far more than it uses — 27 TWh in 2024 against 16 TWh of retail sales. The Colstrip coal plant was the largest generator, and coal still made 36% of the state’s electricity (52% in 2014), with hydro at 34% and wind at 22%.

Low prices follow: the 2024 all-sector average ranked 37th of 51 and homes paid 13.84¢ per kWh over the past year. The electric bill peaks in winter — $141.44 in January 2026 — and the 2020 survey put electric space heating at 3,817 kWh a year in homes that use it, one of the ten largest heating loads. Only 28% of residential meters were advanced meters in 2024.

Cheap gas, heavy propane

Montana’s 2025 residential gas price of $0.847 per therm was the second-cheapest in the country, and 59% of homes heat with gas, at about 753 therms a year. Rural propane homes average 549 gallons a year; EIA’s last price of the 2025–26 season was $2.121. Energy assistance is run by the Intergovernmental Human Services Bureau of the Department of Public Health and Human Services.