Siting Battery Storage in Massachusetts: A New Regulatory Landscape

Battery energy storage systems (“BESS”) are central to Massachusetts’ clean energy strategy. The Commonwealth has committed to procuring approximately 5,000 megawatts of energy storage by July 31, 2030, and procurements are ongoing. At the same time, the regulatory landscape for developing BESS is evolving in fundamental ways. Among the most significant reforms is the new consolidated siting and permitting framework for BESS and other clean energy projects set to begin on July 1, 2026.

Massachusetts’ New Consolidated Siting and Permitting Program

The 2024 Climate Act (St. 2024, c. 239) adopted a new consolidated siting and permitting framework for clean energy infrastructure in Massachusetts. But it required extensive rulemaking processes by the Energy Facilities Siting Board (“EFSB”) and the Department of Energy Resources (“DOER”). After more than a year of regulatory effort, the new framework and its streamlined permitting pathways—including for BESS—are now poised to go into effect.

Under the new framework, BESS projects are classified based on their rated capacity. A BESS with a rated capacity of less than 100 megawatt hours is considered a “Small Clean Energy Storage Facility” and may pursue an optional streamlined approval at the local level. A BESS with a rated capacity of 100 megawatt hours or greater is considered a “Large Clean Energy Storage Facility” and must obtain a consolidated permit from the EFSB.

On July 1, 2026, the new framework opens for applications for “large” projects that require EFSB approval; municipalities are required to offer unified pathways for “small” projects by October 1, 2026, but can choose to accept consolidated applications as early as July 1, 2026.

Here is a quick look at the new permitting rules for large and small BESS:

Consolidated Local Permits for “Small” BESS (225 CMR 29.00)

Once the process is in place at the municipal level, small clean energy infrastructure facilities (including BESS under 100 MWh) may use an optional consolidated permitting pathway to submit a single consolidated application to the host municipality. The resulting approval will encompass all required local permits. Local governments must issue a final decision within 12 months of receiving a complete application. If they do not, the project receives constructive approval. Appeals from local decisions can be taken to the Director of the EFSB.

Local governments may begin accepting these applications on July 1, 2026, and must begin accepting them no later than October 1, 2026.

EFSB Consolidated Permits for “Large” BESS (980 CMR 13.00)

For large facilities, the EFSB will issue consolidated approvals with all necessary state, regional, and local permits. Small facilities can obtain consolidated state (but not local) approval from the EFSB. The EFSB’s review is limited to 15 months for large clean energy infrastructure facilities and 12 months for small facilities seeking a consolidated state permit. If the EFSB does not issue a decision within the set timeframe, the project receives constructive approval, subject to specific rules.

Pre-Filing Engagement (980 CMR 16.00)

One significant piece of the reforms is the increased focus on specific pre-filing requirements. Before filing at the EFSB, applicants must comply with detailed pre-filing consultation and community engagement requirements. These include consultations with the EFSB’s new Division of Public Participation, the Office of Environmental Justice and Equity, the MEPA Office, and all relevant state and local permitting agencies, as well as public meetings and outreach to key stakeholders in the affected community.

The local process for small projects also includes prefiling requirements. Those requirements are set out at 225 CMR 29.08 and in accompanying guidance.

Site Suitability and Cumulative Impact Analysis (980 CMR 15.00)

The new program also introduces site suitability scoring and cumulative impact analysis requirements. Site suitability scoring must inform project design during the pre-filing stage and evaluates proposed project sites across criteria including climate resilience, biodiversity, carbon storage, and existing social and environmental burdens. The Commonwealth has issued guidance, and created an online tool to assist with site suitability scoring.

The cumulative impact analysis requirements are generally only applicable for large facilities going to the EFSB. The rules are set out at 980 CMR 15.00, and in accompanying guidance. A CIA is intended to assess whether a project would create disproportionate adverse effects in communities already facing elevated pollution or public health challenges. The Commonwealth has created an online tool for this purpose as well.

Together with the pre-filing engagement mandates, these provisions are intended to ensure that clean energy projects are sited in ways that are protective of the health, environment, and quality of life of host communities.

Intervenor Support Grants (220 CMR 34.00)

A separate set of reforms may also affect projects that need approvals from the EFSB. The Climate Act also created a Division of Public Participation within the Department of Public Utilities (“DPU”) and empowered it to administer an Intervenor Support Grant Program.

Under that program, community groups, municipalities, and other stakeholders that lack financial resources to participate in proceedings before the DPU or EFSB may apply for grants of up to $150,000 per party, with aggregate funding for any individual proceeding capped at $500,000. Small municipalities (population under 7,500) hosting a facility within their borders are automatically eligible without meeting the financial hardship standard. It is yet to be seen how access to this funding (supported by fees on applicants) will affect participation in DPU and EFSB dockets.

Key Takeaways

Applicants will face a rigorous upfront process that is both complex and untested. That process also imposes certain requirements earlier in the development process, mandating pre-filing community outreach that meets specific requirements and prescribing specific environmental and public health analyses. How stakeholders, including state agencies and municipalities, will engage remains uncertain, and the ability of the decision-makers to meet timelines will be critical. The new permitting framework is poised to accelerate storage deployment without sacrificing local input or environmental safeguards.

BESS developers who proactively prepare for the coming changes and adapt early will be best positioned to advance projects through the inevitable learning curve associated with these new rules.