NorthWestern acquires 10% stake in North Plains Connector HVDC project

NorthWestern Energy has entered into a memorandum of understanding (MoU) with Grid United’s North Plains Connector to acquire a 10% stake in the 3GW HVDC transmission line project. 

The 420-mile (676 km) transmission line will link Bismarck, North Dakota, and Colstrip, Montana.

Grid United will fund the development of the North Plains Connector, with NorthWestern Energy’s investment contingent on regulatory approvals. 

The project, developed jointly with ALLETE, will also involve Avista, Portland General Electric, and Puget Sound Energy.

The North Plains Connector will connect NorthWestern Energy’s Montana and South Dakota service areas and integrate with multiple electricity grids, including the Midcontinent Independent System Operator, Southwest Power Pool, and Western Electricity Coordinating Council. 

The project is currently in the permitting phase, with regulatory approvals anticipated by 2026 and construction set for 2028. Operations are expected to commence in 2032.

Grid United and NorthWestern Energy also secured a $700 million grant from the US Department of Energy’s Grid Resilience and Innovation Partnership programme, primarily to fund the project and potential upgrades to the Colstrip Transmission System.