The proposed SOO Green transmission line between the Midcontinent Independent System Operator and PJM Interconnection regions cleared a key hurdle when it was approved by Iowa regulators last week.

The Iowa Utilities Board on Sept. 13 approved a petition by SOO Green HVDC Link ProjectCo, the project developer, for a franchise to build and operate the Iowa portion of the line. The 525-kV high voltage direct current line would run about 350 miles underground next to a railroad between Mason City, Iowa, and Yorkville, Illinois.

SOO Green expects its project will deliver wind generation from Iowa to the PJM market while improving grid reliability by adding 2,100 MW of transmission capacity between MISO and PJM, according to the IUB’s decision.

“The electric transmission line is necessary to provide adequate electric utility service and is assistive to Iowa electric customers by supporting reliability and regional transmission organization cross-seam transmission,” the IUB said. “Reliability is increased by improved ability to both send and, more importantly, receive power if MISO is experiencing generation shortfalls.”

The IUB’s decision is “a major step in approvals by local, state, and federal regulatory agencies,” David Pacyna, SOO Green HVDC Link ProjectCo CEO, said in an email.

MISO and PJM are reviewing the SOO Green merchant project in their interconnection review processes, according to Pacyna.

Based on PJM’s review schedule, Pacyna said he expects the SOO Green project would receive an interconnection service agreement in the third quarter of 2025.  The project developer is working to align the MISO interconnection study timeline with the PJM process so that the Midcontinent connection agreement is granted at about the same time as the PJM agreement, he said.

The SOO Green project’s commercial operations date will be affected by factors such as supply chain constraints and commercial offtake contracts, but the project developer aims to have the line operating around mid-2029, according to Pacyna.

The Federal Energy Regulatory Commission in 2020 approved SOO Green’s request to be able to negotiate rates for capacity on the line.

Most of the SOO Green line will be on the private rights-of-way owned by Canadian Pacific Kansas City, a railroad company, the IUB said in its decision.

The SOO Green project developer is owned by Copenhagen Infrastructure Partners, energyRe, Siemens Energy, Jingoli Power and PPL Corp., according to Pacyna.

Hickenlooper, Peters introduce transfer capacity bill

The SOO Green project is advancing as FERC and federal lawmakers are considering steps to increase interregional transmission.

Sen. John Hickenlooper, D-Colo., and Rep. Scott Peters, D-Calif., on Friday introduced the BIG WIRES Act, a bill that would require FERC transmission planning regions to be able to export at least 30% of their peak load to neighboring areas by 2035.

If the bill passes, FERC would have 18 months to issue a rule directing regions to meet interregional transfer capacity targets. Regions would have two years to develop their plans after the rule takes effect. The bill wouldn’t apply to the Electric Reliability Council of Texas.

Options for meeting the requirements include building and upgrading transmission lines, installing grid-enhancing technologies such as dynamic line ratings, using energy efficiency to reduce peak demand, and constructing generation or storage to free up capability to move power, according to a summary of the bill.

If enacted, the bill would be “an important first step” in spurring new transmission and creating an “insurance policy” to protect against the effects of extreme weather, but it wouldn’t address the bulk of future transmission needs for enabling reliable and economic decarbonization, RMI analysts said Thursday.

The analysts urged FERC to require “proactive, forward-looking, scenario-based, long-term” interregional transmission planning. Also, Congress should clarify and streamline federal and state permitting for transmission lines, they said.