Solar battery storage in Boston, MA

Massachusetts requires investor-owned utilities to offer net metering for qualifying residential solar systems. Eversource and National Grid (the dominant utilities for most of Greater Boston, with Unitil covering some northeastern MA) credit exported solar against your retail rate. The framework remains stronger than the successor structures several other states have moved to.

SMART (Solar Massachusetts Renewable Target) is a per-kWh production incentive program administered by the Massachusetts Department of Energy Resources (DOER) on top of net metering. SMART pays a tariff for solar generation for a contractually specified term (typically 10 years for residential). The program operates on declining capacity blocks with falling incentive rates as more capacity is installed in each utility territory. Earlier applicants receive higher rates than later applicants in the same block.

Key SMART nuances: per-kWh rates vary by utility territory (Eversource West, Eversource East, National Grid, Unitil) and by capacity block. Battery storage adders apply for systems paired with batteries meeting specific configurations. Low-income, community-shared, and certain land-use adders also exist. Verify the current SMART rate for your utility and zone before signing — terms have shifted multiple times.

Massachusetts also offers a state-level [personal income tax credit](https://www.mass.gov/info-details/residential-energy-credit) for residential solar (a percentage of cost subject to a published cap), which stacks with the federal credit and SMART payments.

The interconnection process: Eversource or National Grid interconnection is required before energization. Your installer files the application, the utility reviews and approves the system design, you install, the local jurisdiction inspects, the utility conducts (or accepts documentation of) a witness inspection, and the system receives permission to operate (PTO). Timeline runs typically 8-16 weeks from application to PTO depending on utility backlog.

For full Greater Boston home-services context — Mass Save framework, climate considerations, related projects — see our [Boston city guide](/cities/boston-ma/).

Boston is one of the few US markets where battery storage produces direct utility revenue, not just bill savings. The ConnectedSolutions program (operated by Eversource and National Grid) compensates qualifying battery owners for letting the utility discharge their battery during peak-demand events.

How it works: you enroll your battery in ConnectedSolutions through your utility. During declared peak events (typically summer afternoons of high grid demand, ~30-60 events per year), the utility automatically discharges a portion of your battery to support the grid. You receive a per-kWh payment for the discharged energy. The program also has winter peak events with similar mechanics in some configurations.

What this means for Boston battery economics: the case for batteries paired with solar in Massachusetts is stronger than in most US markets. SMART battery adders + ConnectedSolutions revenue + outage backup + federal 30% credit produce favorable economics for many appropriate installations. The math works particularly well for Powerwall, Enphase IQ Battery, and other ConnectedSolutions-eligible batteries.

Program caveats: ConnectedSolutions enrollment terms specify event participation requirements and minimum duration. Customers who want full battery autonomy (always available, never dispatched) can opt out, but that forfeits the program revenue. The dispatch is constrained — the utility cannot drain your battery completely or compromise your outage backup.

ConnectedSolutions terms have shifted as the program matures. Verify current enrollment terms and per-kWh compensation rates with your utility before assuming specific revenue figures.

A Greater Boston solar install goes through multiple approval gates: local building/electrical permit through the relevant municipality (which can be unusually slow in dense Boston-area cities), utility interconnection approval (Eversource or National Grid), SMART enrollment, ConnectedSolutions enrollment if battery-included, and final inspection.

Local permit: the City of Boston, Cambridge, Brookline, Newton, Somerville, and other Greater Boston jurisdictions each have building and electrical permit requirements for residential solar. Boston-area permitting timelines are often longer than newer-build markets — older housing stock and dense urban context add review complexity. Permit timeline runs typically 2-8 weeks depending on jurisdiction and current backlog.

Utility interconnection: Eversource or National Grid (depending on your address) handles interconnection per Massachusetts DPU standards. Filed in parallel with the local permit. The utility reviews proposed system design, verifies it meets interconnection standards, and issues conditional approval. After installation and local inspection, the utility issues PTO. The system cannot legally generate to the grid before PTO.

SMART enrollment: handled by your installer as part of the project. The application captures system specifications, capacity block placement, and contract terms.

ConnectedSolutions enrollment: separate from SMART. Handled if battery-included system. Enrollment terms specify event participation requirements.

Final inspection: the local jurisdiction inspects the installed system. Common inspection failures: wire-sizing errors, missing labels on disconnects, inadequate grounding, and missing rapid-shutdown compliance.

For systems including battery storage, both the inverter/battery and the AC-coupling architecture must meet utility interconnection standards plus NEC battery storage code requirements.