The US state of Rhode Island has approved a power deal for output from the 700MW Revolution Wind offshore wind project planned by partners Orsted and Eversource.

The state’s Public Utilities Commission approved a 20-year PPA between National Grid and the Revolution Wind project company, a joint venture between Danish offshore wind giant Orsted and regional utility Eversource.

The Rhode Island approval is a key milestone towards a final investment decision by the partners to build the project, which Orsted entered when it acquired original developer Deepwater Wind. Eversource then took a half share in the project with the Danish group in a deal signed in February this year.

National Grid is set to take 400MW of power from Revolution for Rhode Island, with neighbouring Connecticut in line for another 300MW.

It emerged earlier this year that National Grid agreed to pay about $98/MWh for the power over the 20-year contract, or $74/MWh after accounting for inflation.

The partners hope to commission Revolution Wind in 2023, when it would meet about a quarter of total Rhode Island power needs. The state is already host to Block Island, the first and only operating US offshore wind farm so far built.

“This is a step in adding more clean, reliable offshore wind to Rhode Island’s green energy mix,” Orsted said.