Massachusetts EO 658 responsible data center development (2026)

Massachusetts — Executive Order No. 658: 100% Clean Energy for Data Centers Above 25 MW, Local Approval Before State Permits, Community Benefits Agreements and a Ratepayer Protection Fund (September 8, 2026)
Massachusetts · Mass. Exec. Order No. 658 (Sept. 8, 2026)

Status
In effect
Took effect
September 8, 2026
Applies to
Developers of data centers with peak demand above 25 MW in Massachusetts; state permitting agencies, which may not issue construction permits absent local approval; MassDEP, which must establish the alternative compliance payment mechanism by end of 2026.
Enforced by
Massachusetts Department of Environmental Protection; Executive Office of Energy and Environmental Affairs; state permitting agencies

Massachusetts Governor Maura Healey signed Executive Order No. 658 on September 8, 2026, titled Establishing Requirements for Responsible Data Center Development and Operations in Massachusetts to Protect and Support Ratepayers, Communities, and the Environment. It is the most comprehensive single data center instrument in this dataset, because it combines four mechanisms that other states adopted separately. First, any data center with peak demand above 25 megawatts must meet 100% of its electricity demand with clean energy. Second, developers must obtain local approval before they can seek state construction permits — the same inversion Pennsylvania adopted three weeks earlier, and for the same reason: it stops a developer arriving at a town already holding state authorisations. Third, applicants must demonstrate conformance with state standards on air quality and public health, water use and community engagement, and must submit a community benefits agreement with key stakeholders. Fourth, and the part that gives the clean energy requirement teeth, a developer who does not procure enough incremental clean electricity to cover annual consumption must make an alternative compliance payment, and those funds are credited to a Ratepayer Protection Fund that offsets electricity supply costs for all ratepayers. Compliance with the clean energy requirement can be met by generating onsite, funding construction of nearby new generation, or paying into that fund. The Department of Environmental Protection must stand up the payment mechanism by the end of 2026.

Who is protected: Massachusetts ratepayers, through the clean energy mandate and the Ratepayer Protection Fund that offsets supply costs; host communities, through the local approval precondition and mandatory community benefits agreements; and residents, through air quality, public health and water use standards.

Legal detail

Commonwealth of Massachusetts Executive Order No. 658, signed by Gov. Maura Healey September 8, 2026: 'Establishing Requirements for Responsible Data Center Development and Operations in Massachusetts to Protect and Support Ratepayers, Communities, and the Environment.' FOUR OPERATIVE MECHANISMS: (1) CLEAN ENERGY MANDATE — data centers with peak demand above 25 MW must meet 100% of electricity demand with clean energy generation, satisfiable by onsite generation, funding construction of nearby new generation, or alternative compliance payment; (2) LOCAL APPROVAL PRECONDITION — developers must obtain local approval before seeking state construction permits, inverting the customary sequence and matching Pennsylvania EO 2026-05 of 2026-08-18 (see Pennsylvania EO 2026-05 data center restrictions (2026)); (3) STATE STANDARDS DEMONSTRATION — applicants must show conformance with standards covering air quality and public health, water use, and community engagement, and must submit a COMMUNITY BENEFITS AGREEMENT with key stakeholders, a requirement New Jersey approached through guidance rather than mandate; (4) ALTERNATIVE COMPLIANCE PAYMENT — a developer failing to procure sufficient incremental clean electricity against annual consumption pays into an ACP mechanism, with proceeds credited to a RATEPAYER PROTECTION FUND used to mitigate electricity supply costs for all ratepayers. Implementation: the Massachusetts Department of Environmental Protection must establish the ACP mechanism by the end of 2026. COMPARATIVE NOTE: this is the only instrument in this dataset combining a clean-energy procurement mandate (cf. Delaware HB 445, Nebraska LB 1261), a local-approval-first gate (cf. Pennsylvania EO 2026-05), a mandatory community benefits agreement (cf. New Jersey's fourth pillar, which is guidance) and a compliance-payment fund in one order. Instrument type is an executive order, revocable by a successor governor. Massachusetts municipalities had separately been acting — Holyoke banned data centers outright in June 2026 (see Holyoke MA AI data center ban (2026)) and Westfield adopted a one-year moratorium.

Key facts

JurisdictionMassachusetts
LevelState
StrengthStronger
EnactedSeptember 8, 2026
CitationMass. Exec. Order No. 658 (Sept. 8, 2026)
Private right of actionNo, agency enforcement only
PenaltiesAlternative compliance payments for failure to procure sufficient incremental clean electricity; state construction permits unavailable absent local approval
Topicsdata-center siting and energy · consumer protection · government use of AI · AI disclosure and transparency
Agency pageNo. 658: Establishing Requirements for Responsible Data Center Development and Operations in Massachusetts — Mass.gov

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