The United States' most ambitious large-scale offshore wind farm could only ever be equipped with record-breaking turbines. With 800 megawatts (MW) of capacity, the Vineyard Wind 1 project off the coast of Massachusetts harnesses the Haliade-X wind turbines made by General Electric's renewable energy division. The promise is to save the environment 1.68 million tonnes of carbon dioxide (CO2) emissions every year — equivalent to those emitted in a year by 325,000 SUVs each travelling 77,000 kilometres.

The Vineyard Wind 1 large-scale offshore wind farm

The Vineyard Wind 1 project is promoted by the joint venture Vineyard Wind, headquartered in the city of New Bedford, Massachusetts. Its members include Avangrid Renewables, a subsidiary of Avangrid, and infrastructure-focused investment firm Copenhagen Infrastructure Partners (Cip).

Set to be the largest offshore wind farm in the United States, it will be built approximately 24 kilometres off the coast of Martha's Vineyard, an island south of Cape Cod. It will produce electricity at competitive prices for more than 400,000 homes, delivering output 45 per cent higher than that of the most powerful turbines currently on the market. With a single rotation, each turbine promises to meet the electricity needs of a home — and therefore a household — for a full two days. The project responds to New England's ambitions to use clean energy, including through the installation of 3,200 MW of offshore wind by 2035.

The selection of the site where the facility will be built, and of every component within it — including the underwater cables — is the result of years of work by an intergovernmental task force. "This is an important moment not only for the future of our project, but also for the future of an industry that is poised to grow exponentially over the coming decades," said Lars T. Pedersen, chief executive of Vineyard Wind.

Guaranteed capacity factor of 64%

General Electric's renewable energy division has been selected as the project's preferred supplier. To understand just how fast technological innovation is advancing, one need only consider that just two years ago the world's largest, most powerful and most efficient offshore wind turbine was still in the design phase — and that today it is even more powerful than originally envisaged.

It is in fact available in two versions, with a capacity of 12 or 13 MW. In both, the rotor measures 220 metres and the blade 107. The components are manufactured at the production facility in Saint-Nazaire, France. The promised capacity factor — that is, the difference between actual electricity output over a given period of time and the output expected at full rated power — is 64 per cent. Not bad, considering that the average hovers at less than half that, at around 25–30 per cent.

With a large rotor, very long blades and a high capacity factor, the Haliade-X ensures greater stability and the ability to generate renewable energy even when the wind is blowing less strongly. For its part, General Electric's renewable energy division said it was "proud to work with Vineyard Wind on the first major offshore wind project in the United States," said John Lavelle, chief executive of the offshore wind division.

Cleaner energy from the offshore wind farm by 2023

In order to incorporate the Haliade-X turbines into the project and gain a clearer picture of the construction timeline, Vineyard Wind decided to have the work's construction operations plan (Cop) reviewed by the Bureau of Ocean Energy Management (Boem), part of the United States Department of the Interior. The project requires more than 25 federal, state and local permits and authorisations, most notably from the Boem itself and from the Energy Facilities Siting Board, a key independent agency. It was a decision "not taken lightly," as Pedersen stressed, but one that should avoid "potential further delays" and "accelerate the delivery of the project as planned."

Once the review is complete — a process expected to take several weeks — work on the project will resume from where it left off. Vineyard Wind expects to close the financing by the second half of 2021. Massachusetts, it assures, will receive clean energy by 2023.