Utilities Unitil, National Grid and Eversource Energy on June 29 issued a request for proposals for 400 MW of Massachusetts offshore wind generation, but up to 800 MW will be allowed if the utilities can demonstrate significantly more economic benefit. The bids must include expandable open-access transmission. The RFP is part of a staggered procurement to enter contracts for 1,600 MW in the state by June 30, 2027. The next solicitation will be released within 24 months, the utilities said. Proposals are due on Dec. 20. Expected to bid are Deepwater Wind, which developed the 30-MW Block Island offshore wind farm, the nation’s first; Bay State Wind, which includes DONG Energy and Vineyard Wind, owned by Copenhagen Infrastructure Partners.