Marine

Block Island Wind Farm

The Block Island Wind cable project involved installing a 22-mile transmission cable from Rhode Island to Block Island, a 6-mile export cable from Block Island to the offshore wind towers, and four inter-array cables between the five turbines.

INSIDE THE PROJECT

The Block Island Wind cable project involved two owners: Deepwater Wind and National Grid. Deepwater Wind owns and was responsible for installing the five offshore wind turbines, four 3,200 linear foot array cables between turbines and the six-mile export cable to Block Island. National Grid owns and installed the 22-mile transmission cable between Block Island and Narragansett, Rhode Island. LS Cable was contracted to supply and install all of the 35 kV power cables for the project. LS contracted with Kokosing Industrial Durocher Marine Division to install and bury all cables.

The Durocher Marine installation team designed and constructed a self-propelled, USCG approved, Dynamic Positioned Barge (DP-2) to safely and precisely lay and bury the subsea cable installations. The system utilized six 500 HP thrusters for propulsion that were mounted on a 260-foot by 72-foot by 16-foot ABS barge. Mobilization of the cable lay vessel began in January of 2016 in Florida and was completed in April in Rhode Island. The total 28 miles of cables weighed 3,400 metric tons and were coiled in a holding tank built on the deck of the lay vessel. The installations began in May with the export cable and ended in July of 2016 with the installation of the array cables. The subsea cables were all installed successfully and buried to six feet along the cable lay routes.

WHY IT MATTERS

The Deepwater Wind Farm is the first offshore wind project constructed in North America. It consists of five wind turbines which are located approximately six miles off the East coast of Block Island, Rhode Island and approximately 20 miles from mainland Rhode Island. The combined electric power output from the five wind turbines is 30 MWs which will service 17,000 homes. Prior to the installation of the National Grid transmission line to Block Island and the Deepwater Wind farm, the island relied entirely on diesel generators for electricity. The wind farm will be able to produce electricity for the island at a lower cost and environmental impact than the existing diesel powered infrastructure. The five wind turbines went into commercial service in December 2016.