The North Plains Connector has moved through a major stage of environmental review, with the U.S. Department of Energy and Montana Department of Environmental Quality issuing the project’s Final Environmental Impact Statement on August 28, 2026. The FEIS evaluates the proposed transmission system, which includes an approximately 422-mile, 525-kilovolt high-voltage direct-current line between Colstrip, Montana, and North Dakota, along with three associated AC transmission lines and other facilities.
The final environmental review follows the Draft EIS issued in January 2026 and incorporates public comments and project refinements made during the review process. The North Plains Connector is designed to provide up to 3,000 MW of bidirectional transfer capability, allowing electricity to move between the Western and Eastern Interconnections depending on grid conditions and demand.
The project must still complete its remaining regulatory approvals before construction can begin. Federal agencies are expected to issue Records of Decision as the environmental review concludes, while Montana’s permitting process also requires a final decision under the Major Facility Siting Act. The project’s development schedule targets major construction activities for 2028, followed by commercial operation in 2032.
With the FEIS now complete, North Plains Connector has progressed from environmental analysis toward final permitting, engineering and construction preparation. The project remains one of the largest planned transmission developments in the U.S., with its proposed interconnection between the Eastern and Western grids intended to expand long-distance power transfer capability across the region.
New Engineering Services Agreement (ESA)
Hitachi Energy and Grid United are moving forward with the North Plains Connector, a major transmission project designed to boost electricity flow between the eastern and western power grids of the United States. On October 2, 2025, the two companies announced the new Engineering Services Agreement (ESA), marking the next stage of collaboration on North Plains Connector, which is planned to connect three major U.S. energy markets.
The 420-mile North Plains Connector will operate as a high-voltage direct current (HVDC) system running at ±525 kilovolts. Once complete, it will be capable of carrying up to 3,000 megawatts of electricity in either direction. Enough to power millions of homes and businesses. By linking Montana and North Dakota to the wider grid, the project will support the growing energy needs of AI data centers, industrial electrification, and communities across the country.
Under the ESA, Hitachi Energy will provide early-stage engineering work, including the design of converter station specifications. This step is intended to reduce project risk, strengthen supply chain planning, and speed up overall execution. The agreement builds on the companies’ earlier collaboration announced in March 2024 and underscores their shared commitment to advancing HVDC technology in the U.S.
“Allie Wahrenberger, Vice President of Engineering for Grid United, said the project represents a milestone for the U.S. transmission system. ‘North Plains Connector will be the first transmission system connecting three major U.S. energy markets. Supporting a key Department of Energy goal of enhancing grid reliability and resilience. We are excited to move forward with world-class engineering from Hitachi Energy,’ she noted.”
Connecting Eastern and Western U.S. Grids
The project will integrate the Midcontinent Independent System Operator (MISO), the Southwest Power Pool (SPP), and the Western Electricity Coordinating Council (WECC). By improving grid coordination across these organizations, the North Plains Connector is expected to unlock new capacity, reduce bottlenecks, and strengthen overall reliability. Local communities in Montana and North Dakota are also projected to benefit from job creation and increased tax revenue once construction begins.
Hitachi Energy executives emphasized that the partnership illustrates how early collaboration can help streamline complex projects. “This new agreement with Grid United is a perfect example of how a long-term collaboration built on trust and a shared vision can accelerate delivery and mitigate risk,” said Nathanael Occenad, Vice President and Regional HVDC Sales Manager for Hitachi Energy in the Americas.
Long-distance transmission lines like the North Plains Connector are increasingly critical as the U.S. works to balance abundant low-cost power generation with surging electricity demand. Beyond its regional benefits, the project is aligned with broader national energy strategies, including the White House AI Action Plan, which prioritizes a stronger grid to secure U.S. competitiveness in artificial intelligence and advanced technologies.
Alongside the North Plains Connector, Hitachi Energy is actively advancing other major U.S. initiatives, including a $457 million power transformer manufacturing plant in South Boston, Virginia. The largest such investment in Southside Virginia, set to establish the region as a hub for high-tech electrical infrastructure.
Additionally, the North Plains Connector is part of a broader expansion of long-distance transmission infrastructure across the United States. Another major project now moving into physical construction is the Southwest Intertie Project-North, a 285-mile, 500-kV transmission line connecting Idaho and Nevada. The project represents the final segment of the broader Southwest Intertie corridor and is targeting completion in 2028.
North Plains Connector Project Factsheet
Project Overview
The North Plains Connector is a 420-mile high-voltage direct current (HVDC) transmission line that will be the first U.S. system to directly connect three major energy markets: MISO, SPP, and WECC.
Key Specifications
Technology: HVDC system at ±525 kilovolts
Capacity: 3,000 megawatts (bidirectional)
Length: 420 miles
Service Area: Montana and North Dakota
Project Partners
Developer: Grid United
Engineering Partner: Hitachi Energy
Current Phase: Engineering Services Agreement (ESA) signed for early-stage design work
Strategic Objectives
Connect eastern and western U.S. power grids
Support AI data centers and industrial electrification
Enhance grid reliability and resilience
Unlock new transmission capacity and reduce bottlenecks
Align with Department of Energy and White House AI Action Plan goals
Regional Benefits
Power supply for millions of homes and businesses
Job creation in Montana and North Dakota
Increased local tax revenue
Improved grid coordination across three regional transmission organizations
Project Status
Engineering design phase underway, focusing on converter station specifications and supply chain planning to reduce risk and accelerate execution.
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