Italian cabling giant Prysmian has been awarded a $900m deal to deliver a first-of-a-kind high-voltage direct current (HVDC) transmission line being laid by developer Direct Connect to link renewable energy production from the US heartland with large population centres in the north-east and mid-Atlantic states.

The 525kV SOO Green line, dubbed “first link in the US clean energy grid”, will run underground 350 miles-long between a converter station in northern Iowa and another on the outskirts of Chicago, Illinois, to connect the Midwest Independent System Operator serving the central US, to the eastern PJM Interconnection.

“As can be seen recently in Texas and California, the US must invest in its transmission infrastructure and SOO Green’s underground rail co-location model is a game-changer that can be replicated nationwide to build a clean energy grid,” said Direct Connect CEO Trey Ward.

“Our partnership with Prysmian provides us with best-in-class cable to build a highly reliable and climate resilient transmission line to supply US households and business with affordable renewable energy for decades to come and bring manufacturing back to the US.”

Prysmian CEO Valerio Battista said: “After the award of flagship projects such as the Vineyard [Wind 1] offshore wind farm and the project to upgrade the Washington DC area’s power transmission system, the opportunity to supply HVDC cable for the innovative SOO Green project further solidifies Prysmian Group as the partner of choice for the US interconnector market.”

Civil works for the HVDC project, which once online will supply power to 1.2m homes, will be carried out by Jingoli. Cable production for the project is expected to start in 2023, with Prysmian planning upgrades to its Abbeville, South Carolina cable manufacturing facility for the project.

SOO Green is owned by funds managed by Copenhagen Infrastructure Partners, Siemens Energy, and Jingoli Power.