By Michael Kuser and Rich Heidorn Jr.

BOSTON — Three developers submitted proposals Wednesday in response to Massachusetts’ solicitation for up to 800 MW of offshore wind energy, offering projects that include a transmission “backbone” and storage to enable them to perform like a baseload resource.

The state’s 2016 Act to Promote Energy Diversity mandates that the Department of Energy Resources and the state’s distribution utilities — Eversource Energy, National Grid and Unitil — sign long-term contracts for 1,600 MW of offshore wind by June 30, 2027. (See Massachusetts Bill Boosts Offshore Wind, Canadian Hydro.)

| BithEnergy

The state’s first request for proposals (solicitation 83C) called for a minimum of 400 MW but said the state would consider bids of up to 800 MW if it determines that a larger proposal “is both superior to other proposals submitted in response to this RFP and is likely to produce significantly more economic net benefits to ratepayers.”

The three developers — all with ties to the state’s utilities — have purchased renewable energy leases off the coast from the federal Bureau of Ocean Energy Management.

Bay State Wind

Bay State Wind, a joint venture between Ørsted and Eversource, proposed a 400-MW or 800-MW wind farm 25 miles off of New Bedford. It would be paired with a 55-MW battery storage facility, “the largest battery storage system ever deployed in conjunction with a wind farm,” it said.

Ørsted, formerly DONG Energy, is the No. 1 offshore wind generator in the world. The company would use New Bedford as the staging area for construction and the base of its operations and maintenance through the wind farm’s lifetime. The storage facility and an onshore substation would be located in Somerset.

Deepwater Wind

Deepwater Wind’s proposal would firm its project’s wind output through an agreement with the largest hydroelectric pumped storage facility in New England, the 1,200-MW Northfield Mountain station operated by FirstLight Power Resources.

Interior of Northfield Mountain pumped storage facility | Northfield Mountain

Deepwater proposed two versions of Revolution Wind, a wind farm of approximately 25 turbines to generate 200 MW, or double that size to generate 400 MW. The company had proposed an initial 144-MW phase of the project in response to the state’s 83D solicitation for 9.45 million MWh of clean energy. The state is due to announce winners of that RFP on Jan. 25.

Deepwater is the developer of the Block Island Wind Farm off Rhode Island, the nation’s first commercial offshore wind farm. It also partnered with National Grid Ventures to propose an offshore transmission “backbone” scalable to 1,600 MW that would be open to other wind developers. (See Offshore Wind Developers Ponder Tx Options.)

The company’s project would connect to land at the Brayton Point substation in Somerset.

Vineyard Wind

Vineyard Wind, a joint venture of Avangrid Renewables and Copenhagen Infrastructure Partners, is betting that its promise to deliver an operating project by 2019 will win the state’s favor. It submitted proposals for 400-MW and 800-MW wind farms, with approximately 50 and 100 turbines, respectively. Avangrid owns Unitil.

| BOEM

Vineyard Wind said it has already submitted applications with BOEM and the state Department of Public Utilities’ Energy Facilities Siting Board for the wind farm, about 15 miles south of Martha’s Vineyard. “By filing for construction permits, Vineyard Wind is on track to complete the permitting process in time to begin construction in 2019,” it said.

Deepwater said if it is selected it would begin construction in 2022, with the project in operation in 2023. Bay State did not mention a timeline in its press release.

The state will announce the winners of the offshore wind solicitation on April 23, 2018, and contracts are to be submitted at the end of July.

This month saw an early offshore wind project, Cape Wind, exit the stage. It announced Dec. 1 that it had notified BOEM it was stopping development of its proposed wind farm project in the Nantucket Sound and filing to terminate its offshore lease issued in 2010.

Nevertheless, the state’s solicitation has been a cause for optimism among green energy advocates, who note the attractiveness of the Atlantic’s strong winds and shallow waters. (See ‘Momentum’ Seen for U.S. Offshore Wind.)