Power Utility MDU Resources Joins North Plains Connector Project

North Dakota-based MDU Resources, a utility holding company with a construction services arm, said it has joined a consortium of partners to build the North Plains Connector, a planned 420-mile, 3000 MW HVDC transmission project that will connect the Eastern and Western Interconnections.

MDU Resources signed a non-binding memo of understanding with the project’s LLC, which is a unit of Houston-based transmission developer Grid United. The utility company would now own 150 MW of the completed project’s capacity once it is energized. North Plains Connector LLC will continue to fund the development of HVDC project.

The up-to 525kV transmission line’s planned route would take it from Colstrip in southeast Montana to two locations in central North Dakota (the towns of Center and St. Anthony), boosting the Eastern and Western Interconnection’s ability to draw on plentiful hydropower, wind power and solar power sources throughout the north-central US.

In a press release, the company said this new transmission line would become an important part of the company’s power grid, as 150 MW represents about 15% of the utility’s peak load in 2024.

Once completed, the project would be among the first HVDC transmission connections among three regional electric energy markets — the Midcontinent Independent System Operator, the Western Interconnection and the Southwest Power Pool, according to a release from project developers. It will be capable of transmitting electricity bidirectionally, depending on local market needs and resource availability.

The transmission line project represents a nearly $3.2 billion investment in Montana and North Dakota.

Other participating utilities in the project include Puget Sound Energy, Portland General Electric, NorthWestern Energy and Avista Utilities. BHE U.S. Transmission, a Berkshire Hathaway unit and transmission owner, operator and developer, has also signed a capacity MOU with the project.

Hitachi Energy will provide engineering services for the HVDC system, delivering early-stage engineering services, including the development of technical specifications for the HVDC converter stations.

The project is being developed by Grid United and publicly held energy services company Allete Inc. Other Grid United power line projects include the Wyoming Intertie, the Three Corners Connector, the Pecos West Intertie and the Southline Transmission Project.

According to the project’s website, North Plains Connector is in the permitting phase and is initiating regulatory filings, with approvals expected in 2026. Construction is expected to commence in 2028, and the line is expected to be operational in 2032.