This page provides an overview of the SOO Green HVDC Link project. For additional information, register for the Open Solicitation to gain access to documents including the complete Information Memorandum, and visit the project website at


The SOO Green HVDC Link is a first-of-its-kind electric power infrastructure project:

  1. first project to co-locate an HVDC transmission line underground, alongside railroad right-of-way;
  2. first major transmission project to cross the seam between MISO and PJM, connecting two strong grids and creating opportunities to satisfy growing customer demand for zero-carbon electricity in PJM with abundant renewable energy in MISO;
  3. first project to provide consumers in PJM (the nation’s largest electricity market) with direct access to a highly reliable and robust source of renewable energy from resource-rich MISO.

The $2.5 billion Project is anticipated to be in service in Q4 2024.

Project Overview

The SOO Green HVDC Link will consist of three components:

  1. a converter station, featuring state-of-the-art VSC technology that will convert alternating current (“AC”) power from MISO’s 345 kV transmission system into direct current (“DC”) output for transmission;
  2. a 350-mile, HVDC transmission line consisting of a pair of five-inch, 525 kV rubber-based XLPE cables installed in trench two and a half feet wide and five-feet deep; and
  3. an AC converter station (also utilizing VSC technology) that will convert the DC power into AC power for transmission on PJM’s 345 kV system and beyond.

Significantly, the SOO Green HVDC Link will be installed within Canadian Pacific Railway’s right-of-way. This innovative partnership vests SOO Green with the necessary right-of-way for nearly all of its 350-mile route.

Environmental Impact

The SOO Green HVDC Link was designed and will be constructed and operated to minimize environmental impacts. By installing the conductor cable underground along existing railroad right-of-way, SOO Green will eliminate the visual and environmental impacts typically associated with large-scale overhead transmission. The Project will utilize safe materials: the electricity-conducting cable is well-insulated, produced from non-flammable materials and does not require any cooling liquids or gels. The electric fields produced by the underground high-voltage lines will not harm humans, animals, plants or interfere with railroad operations.

Permitting process

SOO Green is committed to working in collaboration with federal, state and local agencies to meet or exceed compliance with all applicable laws and regulations throughout the permitting process. Installation of the transmission line underground along an existing railroad right-of-way has garnered support at the local, state, and federal agency levels and will undoubtedly simplify the Project’s permitting process.

SOO Green has commenced permitting efforts with a number of federal, state, and local jurisdictions including the Army Corps of Engineers and the Iowa Utilities Board. SOO Green will notify landowners adjacent to the Project’s path before crews begin surveys and other work. Indeed, SOO Green has begun hosting informational meetings in each of counties along the project’s route.

Project Benefits

The SOO Green HVDC Link will provide a number of significant benefits; it will notably:

  • reinforce the transmission grid as an inter-regional “backbone” transmission facility linking the transmission systems operated by MISO and PJM, and increase the transfer capacity on the existing grid;
  • offer compelling market opportunities via a more direct, efficient and controllable path for energy and capacity to flow between the two systems, which in turn should facilitate price convergence between the regions and make each market more efficient;
  • connect to a strong point on the MISO system, allowing the SOO Green transmission line to draw energy and capacity from different generation resources across the entire region, and increasing the geographic diversity and number of hours in which different types of generation resources can utilize the line, thus increasing the amount of capacity and energy that can be sold into PJM;
  • reduce viewshed and environmental impact through underground co-location within an existing pre-disturbed, privately owned railroad right-of-way, which not only avoids impacts to neighboring landowners and the need for extensive use of eminent domain to secure real estate rights, but also avoids or minimizes the typical impacts of overhead transmission line construction on sensitive environmental areas, including wetlands and forested areas; and
  • promote reliability — VSC power flow is one hundred percent (100%) controllable and can:

– provide large amounts of reactive power controllability, independent of real power transfer;

– aid in frequency control, given the fast power controllability;

– meet the exact active power transfer demanded;

– provide spinning reserves; and

– assist in congestion management.

Additional information about the SOO Green HVDC Link development and value proposition is available to Registered Participants to the Open Solicitation, and by visiting the project website by clicking the logo below