Minnesota Power Secures Regulatory Approval for Transmission Line Upgrade

The Minnesota Public Utilities Commission on Aug. 2 approved Minnesota Power’s high-voltage direct-current, or HVDC, transmission project designed to increase capacity to prepare the system for future expansion and address grid reliability. The approval allows for a capacity of up to 900 megawatts (MW), up from the current 550 MW capacity. The project is estimated to cost between $600 million and $940 million.

The project will upgrade the aging grid infrastructure to reduce production costs, improve grid reliability, and integrate clean energy sources. Construction is expected to start this year, with the transmission system potentially commencing operations between 2028 and 2030.

At present, the 465-mile HVDC transmission system distributes electricity generated through wind to residents between North Dakota and Minnesota. The aging transmission line, which has been in service since 1977, has been susceptible to control system failures and terminal outages. The annual cost associated with outages and failures is estimated to be $7 million.

The project will construct a new converter station at the Arrowhead Substation in Hermantown, which will connect to a new substation via three additional transmission lines. The upgrade will also aim for a more flexible energy flow between terminals in North Dakota and Minnesota, incorporating bi-directional line capability.

The project costs will be partially covered by funding from state and federal programs. In October 2023, the U.S. Energy Department awarded $50 million towards the HVDC Terminal Expansion Capability Project, as a part of the 2021 Infrastructure Investment and Jobs Act funding. Minnesota Power also received $15 million in state funding as part of an energy and climate budget bill passed in 2023. Further, the company secured $10 million from the state competitiveness fund supporting the cost-share requirements of the U.S. Energy Department grant.