News, Articles & Events

By Brian Bird, President & CEO, NorthWestern Energy

On Jan. 1, NorthWestern Energy will take a decisive step to secure our state’s energy future. Our ownership in Montana’s Colstrip Plant will increase from 15% to 55%. We are guided by a singular responsibility -- to meet our obligation to provide reliable, cost-effective energy service for our customers.

This plan has been in the works for three years.

Today NorthWestern Energy owns 222 megawatts of the Colstrip Plant, on-demand generation that keeps the lights on, cost effectively, for Montana families and businesses in all weather conditions. The Colstrip Plant is a critical piece of the portfolio of generation resources serving our Montana customers – a portfolio with more than 58% wind, solar and hydro generation today.

In early 2023, NorthWestern Energy announced plans to acquire an additional share of the Colstrip Plant from Washington-based Avista, to provide our Montana customers with a more balanced mix of energy resources.

In July 2024, we announced plans to acquire another share of the Colstrip Plant from Washington-based Puget Sound Energy.

Washington state law requires Avista and Puget Sound Energy to exit the Colstrip Plant on Dec. 31. In Montana, the plant’s on-demand generation remains essential to keeping the lights on and homes warm in our state at reasonable rates.

With 55% majority ownership, we can protect this critical resource from premature closure driven by out-of-state interests. We will guide operational investments so the plant continues to deliver cost-effective, around-the-clock energy for Montana communities.

Montana customers have depended on unpredictable energy markets for supply, mostly from out of state, to meet peak energy demand for too long. When temperatures plunge and the demand for electricity spikes, market prices can soar – and supply can be scarce.

For decades, energy service providers in Montana owned power generation facilities to supply electricity to their customers. In 1997, the state deregulated the energy generation industry, ending that long-standing policy. However, deregulation failed and resulted in higher energy costs for Montanans. In response, lawmakers changed state law in 2007 to allow energy service providers to once again own power generation facilities and serve their customers directly.

Over the last 18 years, NorthWestern Energy has added nearly 1,100 megawatts of power generation to serve our Montana customers. More than half of this comes from renewable wind and hydro generation.

When the wind isn’t blowing and the sun isn’t shining, Colstrip is there. This acquisition strengthens our generation portfolio and reinforces a stable energy backbone for Montana.

The added capacity from Avista’s and Puget Sound Energy’s shares of Colstrip come at no purchase price, avoiding the enormous expense of building or buying a similar resource.

This is responsible progress.

We’re committed to a cleaner energy future, but you don’t tear down one bridge until another is built. The Colstrip Plant will keep the lights on in Montana in all weather conditions as we safely and cost-effectively transition to new carbon-free technologies.

This acquisition also opens the door to new opportunities.

Montana is attracting interest from the data center industry. With expanded generation capacity, NorthWestern Energy is positioned to support that economic opportunity in Montana while existing customers are protected.

Generation from the Puget Sound Energy share of the Colstrip Plant isn’t needed in the near term to serve our Montana customers’ energy demand –the cost of operations and maintenance of this share will not be included in customer rates. However, acquiring the Puget Sound Energy share means we gain majority ownership of the plant and the flexibility to serve future energy growth in Montana.

Our priority is reliable, affordable energy for Montana families and businesses. We’re working collaboratively with stakeholders on a plan that supports economic development while protecting the interests of all Montanans. Together, we are building an energy strategy that strengthens our communities and secures long-term prosperity.

This is more than an energy transaction. It’s a promise to Montana. By securing the Colstrip Plant’s capacity today, we’re safeguarding reliability during the harshest weather—and creating space for tomorrow’s opportunities.

Reliability comes first. And with this acquisition, Montana can move forward with confidence -- toward an energy future that is both secure and prosperous.