ITC Midwest moves forward with Upper Midwest’s first 765-kV transmission line

ITC Midwest and two other companies are moving forward with an Upper Midwest transmission project that will bring the first 765-kilovolt transmission line to the region to boost grid reliability.

The project — approved by the Midcontinent Independent System Operator, or MISO board of directors — is one piece of the largest electric grid expansion project in U.S. history.

The transmission line was one of several approved in December by MISO, the power grid manager of a region that spans east of the Rock Mountains and includes Iowa, along with 14 other states and a Canadian province.

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The 765-kV transmission lines will be able to carry large amounts of electricity over longer distances, compared to lower voltage lines. And that’s important, as demand for energy grows.

Iowa “and every other state right now seems to have an insatiable appetite for energy, which is growing,” said Steve Guyer, energy policy counsel for the Iowa Environmental Council. “Simply put, if we don't have transmission, we can't get the power to where it's needed. And so the reason 765 (kV transmission line) is important is, as that demand grows, we have to have bigger lines to carry more energy, which is what this is all about.”

ITC, in partnership with electric company Xcel Energy and Great River Energy, a wholesale electric power cooperative, will build the 765-kV transmission lines in several segments. The lines will be built above ground.

“This transmission line will provide significant benefits to our communities, ensuring we meet the unprecedented growth in their demand for electricity while keeping costs low for homes, farms and businesses,” the three companies said in a joint news release. “Some estimates project electric use to double over the coming decades in our region. The 765-kV line is key to maintaining reliability while maximizing the efficient use of land and reducing the overall impact to landowners.”

The line will connect to the existing transmission grid in eastern South Dakota and will span about 410 miles, crossing through southern Minnesota, and into Iowa and Wisconsin.

The companies said the transmission lines will be a “backbone” in energy infrastructure across the Midwest. According to MISO, investing in higher-capacity lines — like 765-kV — means future costs to upgrade or build additional lines can be avoided.

The 765-kV project was one of 24 approved by MISO’s board. The projects will invest a total of $21.8 billion in transmission, including several 345-kV projects in Minnesota, North Dakota and South Dakota.

The two 765-kV transmission lines in Iowa will run south from a substation in southwest Minnesota, to a new substation near Adair, west of Des Moines. The other will run from the Adair substation, to a substation east of Marshalltown. The line from Minnesota to Adair will cost about $1.375 billion to build, and the line from Adair to Marshalltown is projected to cost $1.583 billion.

The companies are anticipating the transmission line — which will be the first 765-kV transmission line in the Upper Midwest — to be in service by 2035.

Long-range transmission plan

The 765-kV transmission line project is part of MISO’s Long-Range Transmission Plan, which is one piece of the MISO Transmission Expansion Plan. In the project, there are four phases, or “tranches.”

Tranche 1 was approved in 2022, and included a $10.3 billion power line portfolio for the Midwest. The project includes 18 transmission lines spanning across the Midwest, with five — either wholly or partially — in Iowa.

Tranche 2 is the current phase, and includes two subphases. Tranche 2.1, which includes the 765-kV transmission lines, was approved in December 2024 and builds on Tranche 1.

Tranches 2.2, 3 and 4 are still upcoming and will focus on other subregions of MISO’s reach.

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How much power is 765-kV?

A single 765-kV electric transmission line can deliver about the same amount of electricity as six 345-kV transmission lines. Installing lines with larger capacity maximizes land use and lessens the impact on landowners.

Guyer, at the Iowa Environmental Council, said each 765-kV transmission line can transmit between 2,000 and 2,400 megawatts of energy.

“That’s like transmitting power to four nuclear energy plants,” Guyer said.

The companies said constructing the new transmission lines will meet the “significant growth” in electricity use that is projected in the coming decades and will improve access to new energy sources needed to serve communities throughout the region.

Some of the increased demand comes from a growing number of data centers in Iowa and across the Midwest. Two data centers are planned to be built in southwest Cedar Rapids in the coming years.

ITC Midwest operates more than 6,600 circuit miles of transmission lines in Iowa, Minnesota, Illinois, Missouri and Wisconsin and has its headquarters in Cedar Rapids.

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“Modernizing the electric grid provides tremendous benefits for electricity consumers through improved reliability, increased capacity and greater access to diverse generation resources,” ITC Midwest President Dusky Terry said in a Feb. 10 news release. “We are committed to working with landowners, local communities and our utility partners throughout the process to meet the growing demands on the electric grid across Southern Minnesota.”

To date, ITC Midwest has completed 40 new generator interconnections, which allows electricity generators like wind or solar to connect to and deliver energy to the electric grid. The transmission company also has added approximately 4,939 megawatts of new generating capacity to the grid — including approximately 4,230 megawatts of wind energy production capacity.

What’s next?

On Feb. 7, ITC Midwest, Great River Energy and Xcel Energy filed a notice of Intent to Construct, Own and Maintain the new 765-kV transmission line with the Minnesota Public Utilities Commission.

The notice kicked off the permitting, public outreach and environmental review process overseen by the Commission and is the first step in project development. Similar notices will be filed in other states — including Iowa — as part of the development process, the news release said.

Before transmission lines can be built, two permit approvals are required. They include a Certificate of Need outlining the project's need, the benefits the state and region will receive if approved, and a Route Permit, which will determine where the transmission line will be located.

The companies expect to file a Certificate of Need application in Minnesota in early 2026. The companies said they will “work closely with landowners and communities throughout the project area” to help determine the best locations for the line, which they will include in their Route Permit application.

Each of the application’s review processes takes about 12 to 18 months. They will include public information meetings and hearings throughout the project areas.

Olivia Cohen covers energy and environment for The Gazette and is a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues.

Comments: olivia.cohen@thegazette.com

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