NorthWestern Energy enters into strategic agreement to secure reliable, cost-effective energy service for Montana

Butte, Mont. – Jan. 16, 2023 – NorthWestern Energy and Avista announce an agreement to provide NorthWestern Energy’s Montana customers needed on-demand power generation capacity and allow Avista to exit ownership of the Colstrip plant in accordance with the state of Washington laws.

• NorthWestern Energy will acquire Avista’s ownership of Colstrip Units 3 & 4, 222 megawatts, with no purchase price, effective on Jan. 1, 2026.
• Avista will retain its obligation for its portion of environmental and decommissioning costs associated with the future closure of the plant.
• NorthWestern Energy will be responsible for operational costs for the 15% shares of Colstrip Units 3 & 4 when ownership is transferred.
• Avista and NorthWestern Energy will prorate Avista’s share of the cost of certain capital expenses for the Colstrip plant from now through Jan. 1, 2026.

“More resources that can generate power on-demand, 24/7, located in Montana and dedicated to serve Montanans, are needed to meet our responsibility to provide our customers with reliable energy service, keep them safe in all weather conditions and avoid an energy crisis,” said NorthWestern Energy President and CEO Brian Bird. “This agreement addresses that risk and saves our Montana customers the significant cost of acquiring new generation. It solidifies NorthWestern Energy’s path to achieve our Net Zero Emissions by 2050 commitment, ensuring we can continue to provide reliable energy service at the most affordable rates until other technology for on-demand, clean generation is cost effective.”