National Grid completes sea2shore cable landing

By Darlene Masse

In a major victory for renewable energy, National Grid has completed a critical link in the development of the nation’s first offshore wind farm. The installation of the 20-mile undersea cable connecting the Rhode Island mainland to Block Island is now complete. This is an impressive feat, considering the journey of the cable.

As we detailed in a February article, the custom-designed submarine cable will interconnect to the nation’s first offshore wind farm and transport clean, renewable energy from Block Island to Narragansett. The undersea cable was built in South Korea, spent nearly two months traveling by barge across the Atlantic Ocean, arrived in Rhode Island’s Quonset Point in early April, and has now successfully been installed between Scarborough State Beach in Narragansett, RI and Crescent Beach on Block Island. The diagram below details the work involved in burying the submarine cable.


“This significant milestone in developing renewable offshore wind generated energy is the result of years of work by hundreds of people,” said Rudy Wynter, President and COO of National Grid’s FERC regulated businesses. “Everyone involved in this project can be proud of what has been accomplished.”

The cable will ultimately be connected to a new National Grid substation being constructed on the island and to an existing substation in Wakefield, RI on the mainland. The same cable will also interconnect the privately owned Block Island Power Company (BIPCo) to the mainland. Until now the island’s electric power needs were met through diesel-powered generation. Once the system is energized, National Grid will purchase the output from the Deepwater Wind Farm through an agreement approved by the Rhode Island Public Utilities Commission and feed the power into the regional transmission system. BIPCo will purchase its power through the energy markets. A portion of that power will include output from the Deepwater Wind Farm.

“We still have several months of construction work and testing to complete before the system can be energized,” said Wynter. “We’re continuing to work closely with Deepwater Wind, BIPCo, the towns of New Shoreham, Narragansett, South Kingstown as well as state, local and federal permitting agencies to complete the project this fall.”

The nearly five-million pounds of undersea cable that connects the Deepwater Wind Farm to the island and the island to the mainland was manufactured in South Korea by LS Cable, which was also the company overseeing the installation of the cable for National Grid and Deepwater Wind.

Connecting the undersea cable to newly installed underground cable on the island will be completed this week. Underground duct banks through which connecting electric cables will run have been installed in Narragansett, South Kingstown and on Block Island and approximately 90 percent of the underground cables are in place. Cable splicing, overhead line, and substation construction will continue over the summer months. Substation testing and commissioning is scheduled to begin after Labor Day.

To learn more about the project, visit

Congratulations to everyone who has worked on this project on accomplishing this major milestone!

National Grid Sea 2 Shore project Block Island, RI National Grid Sea 2 Shore project Block Island, RI National Grid Sea 2 Shore project Block Island, RI National Grid Sea 2 Shore project Block Island, RI
Download PDF
Add To wishlist

One Comment

Ron Macklin

Congratulations on this milestone. I know a lot of hard work from across our company went it getting to this point.


Leave a Reply

Your email address will not be published. Required fields are marked *