Share in Colstrip power generation unit in Montana will be sold  

BELLEVUE — Puget Sound Energy says it is one step closer to having a coal-free generation mix with the sale of its share of Colstrip Unit 4 in Montana to NorthWestern Energy.

This deal will allow PSE to move farther and faster to supply clean energy for its customers by eliminating nearly 50 percent of coal from its portfolio years ahead of schedule. Under Washington’s Clean Energy Transformation Act, all electric utilities must eliminate coal-fired electricity from their portfolios by 2025.

“This is what our customers have been asking for, and we have been on a path to it for years,” said David Mills, PSE senior vice president of Policy & Energy Supply. “We’re excited to take this major step forward in creating a better energy future for our customers and the state of Washington.”

The change in ownership is effective upon approval by the Washington Utilities and Transportation Commission, which includes NorthWestern taking ownership of 185 MW from PSE. PSE has signed a power purchase agreement with NorthWestern for 90 MW until 2025 to facilitate the transition for both companies.

“While we are taking actions to fulfill our commitment to our customers, we also stay committed to the people of Colstrip,” said Ron Roberts, PSE director of Generation & Natural Gas Storage. “We’re proud to be the first Colstrip owner to set aside funding for the community’s transition planning efforts through a $10 million contribution to the Colstrip Community Fund. We will also remain in Colstrip for years through the decommissioning and remediation work.”  

PSE’s coal portfolio will drop by 307 MW in early January when plant operator and co-owner Talen Energy closes Colstrip Units 1 & 2. PSE will continue to be one of five owners of Colstrip Unit 3, which provides about 185 MW to the utility’s customers. On average, 100 megawatts of coal generation serves approximately 78,000 households.