In coordination with the Massachusetts Department of Energy Resources (DOER), the state’s investor-owned electric distribution companies have issued a joint request for proposals (RFP) for 400 MW of offshore wind generation – including renewable energy credits – and associated transmission.

According to law firm Pierce Atwood, the companies are seeking to enter long-term contracts for 15-20 years and are allowing the procurement of up to roughly 800 MW in certain circumstances. In addition, all projects must enter commercial operations before Jan. 1, 2027.

Pierce Atwood says this RFP is the first of “several, statutorily-required solicitations” Massachusetts will announce in order to meet its goals for reducing greenhouse-gas emissions, as well as procuring 1.6 GW of offshore wind capacity by June 30, 2027.

The firm says the companies will consider proposals beyond 400 MW of capacity if a “larger-scaled proposal is both superior to other proposals … and is likely to produce significantly more net economic benefits to ratepayers.”

The companies are Fitchburg Gas & Electric Light Co., d/b/a Unitil; Massachusetts Electric Co., d/b/a National Grid; Nantucket Electric Co., d/b/a National Grid; NSTAR Electric Co. d/b/a Eversource Energy; and Western Massachusetts Electric Co., d/b/a Eversource Energy.

The deadline for submissions is Dec. 20.