A development company wants to build a 349-mile underground transmission line that would carry renewable energy from wind-rich rural Iowa to high-demand eastern U.S. cities.

Direct Connect Development Co. said Monday it wants to build a 2,100-megawatt high-voltage transmission line that would run underground from Mason City to the Chicago area along existing railroad lines, primarily the Canadian Pacific.

The project, called SOO Green, is expected to cost about $2.5 billion and could be operational by 2024, the company said. It would need permits from several local, state and federal agencies, including the Iowa Utilities Board and the Iowa Department of Natural Resources, to go ahead with the project.

Iowa is a national leader in wind energy generation, although utilities are running into more opposition from rural Iowa landowners, who are concerned about noise from the turbines and their impact on farmland, among other issues.

Direct Connect said it can limit the project's environmental impact "by boring under sensitive habitat, limiting the impact on birds and other endangered species."

"Building SOO Green underground and utilizing an existing railroad right of way will also limit impacts to neighboring landowners," the company said in a news release.

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It's similar to the model used to build America’s fiber optic system, Direct Connect said.

After running into opposition from landowners, Rock Island Clean Line withdrew its plans in 2016 for a $2 billion, 500-mile overhead transmission line that would have funneled wind energy across 16 counties from northwest Iowa into Illinois and states farther east.

Even with additional transmission lines under construction, more capacity is needed, said Kerri Johannsen, the Iowa Environmental Council's energy program director.

When the new transmission lines are completed, they "will already be at full capacity for carrying existing and proposed renewable energy projects to market," Johannsen said. "Once again, we are faced with the need to bolster our transmission system."

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Direct Connect said Monday that building the high-voltage line underground and along railroads would "create a market segment that doesn’t exist today."

"SOO Green will serve as a renewable energy hub by connecting two of large electric power markets in the United States — MISO and PJM," the company said. "This creates a convenient location for a large number of renewable energy buyers and sellers to enter into standard transactions."

The company said its primary investors are Copenhagen Infrastructure Partners, Jingoli Power and Siemens Financial Services.

Siemens would be responsible for the overall system design, engineering, manufacture, civil works, installation and commissioning of the high-voltage direct current transmission line.