Two East Coast Offshore Wind Farms Deliver Their First MWs of Power

Vineyard Wind 1 and South Fork Wind, the first commercial-scale offshore wind plants in the U.S., have started delivering their first megawatts in Massachusetts and New York. At full build-out in the coming years, the pair will supply 938 MW of new capacity to the grid. 

 

Vineyard Wind offshore wind project near Martha’s Vineyard. Image used courtesy of Bureau of Ocean Energy Management

 

The wind facilities represent a significant milestone for America’s growing offshore wind market, which previously comprised only two operational offshore wind farms—Block Island in Rhode Island, with 30 MW of generation capacity, and Coastal Virginia Offshore Wind, with 12 MW. 

The latest projects come as the U.S. offshore wind energy development pipeline reached 52.6 GW of generating capacity in mid-2023, according to the latest data from the Department of Energy. This figure marks a 15% year-over-year increase (or 6.9 GW), driven by three new lease areas adding 4.8 GW of capacity in the Gulf of Mexico. 

Still, despite this activity, economic pressures remain a significant barrier in the offshore wind industry. In recent months, several developers have canceled upcoming projects, citing inflation, supply chain shortages, and higher interest rates for financing. 

 

U.S. offshore wind project pipeline by status as of mid-2023. Image used courtesy of the Department of Energy (Page 32) 

 

Vineyard Wind to Add 806 MW to Massachusetts’ Grid

The first of 62 planned turbines has started delivering 5 MW to New England’s grid as part of the Vineyard Wind 1 project, 15 miles away from Martha’s Vineyard and 35 miles from mainland Massachusetts. 

After additional on and offshore testing, five turbines will begin operating in early 2024 at 13 MW each. After the other 50-plus turbines are installed, Vineyard Wind will generate 806 MW to serve over 400,000 Massachusetts homes and businesses through an interconnection with the Barnstable grid. It’s expected to displace more than 1.6 million metric tons of carbon emissions annually. 

The project required more than 83 miles of high-voltage alternating current cable and over 31 miles of overland cable. The underground cables transmit power to a substation in Cape Cod. The 5,000-ton offshore substation was completed last year as the first in the U.S. 

Vineyard Wind is a joint venture between Connecticut-based Avangrid and Danish investment firm Copenhagen Infrastructure Partners, which both developed and constructed the project with more than 900 workers. 

 

Haliade-X wind turbine specifications for the 14 MW option. Image used courtesy of GE

 

Vineyard Wind features General Electric’s Haliade-X offshore turbines. Haliade-X is one of the world’s most powerful models, with a 60-64% capacity factor beating the 42% global average in the offshore wind industry. 

Each 14 MW unit can generate 74 GWh of gross annual energy production (AEP). Haliade-X turbines are about 853 feet tall, comprising 351-foot-long blades and a 721-foot rotor. 

GE continues to scale up the capacity of its Haliade-X turbines. At an investor conference last year, an executive said the company plans to start 17-18 MW orders in 2024 or 2025. 

 

South Fork Wind Will Generate 132 MW for New York Customers

South Fork Wind has started delivering power to Long Island through its first operational wind turbine 35 miles from the Montauk Point shore. Two turbines have been installed, and another 10 will be added in the coming months. 

The project, a joint venture between Danish energy giant Ørsted and Massachusetts-based Eversource, will generate 132 MW for about 70,000 homes. It’s expected to eliminate up to 6 million tons of carbon dioxide emissions annually. 

 

Location of South Fork Wind. Image used courtesy of Bureau of Ocean Energy Management

 

South Fork Wind marks the first American-built offshore wind substation. Hundreds of workers supported the project’s construction, which launched in 2022 with the onshore export cable system linked to the Long Island Power Authority’s grid. The first monopile foundation was installed in mid-2023, followed by the turbine. An offshore installation vessel placed the steel tower onto the base with a crane. Then, developers installed the nacelle and rotor atop the tower. The blades were lifted and bolted onto the rotor. 

An additional 100 workers helped build the onshore cable system, including the underground duct bank and interconnection facility. The underground transmission cables deliver power to the East Hampton grid. 

According to the Pacific Northwest National Laboratory, South Fork Wind’s inter-array cables range from 34.5 to 66 kV of power, while the buried seafloor AC cable voltage is 138 kV. Water depths range from 108 to 134 feet. 

The project uses Siemens Gamesa’s SG 11.0-200 DD wind generators, which range in capacity from 6 to 12 MW each. The turbine hub is 331 to 472 feet tall, the rotor diameter is about 656 feet, and the blades stretch 318 feet long. 

 

The SG 11.0-200 DD turbine. Image used courtesy of Siemens Gamesa

 

The SG 11.0-200 DD model has up to 40% AEP compared to its 8.0-167 DD predecessor, an expansion that involved upgrading the direct drive generator to a larger diameter and increasing the rotor size.