Net Metering by State

What your electric utility actually pays for exported solar power.

Massachusetts solar export compensation

What Massachusetts pays for exported rooftop solar power, with the source and the date each figure was checked.

Record verified 2026-09-16 · 18 of 17 fields sourced

What does your utility pay?

No single rate — formula based

Formula varies by customer/facility: standard solar generally 100% of applicable basic-service + distribution + transmission + transition kWh charges; new solar generally 60% market credit; qualifying public-entity cases can receive 100%.

Eversource (MA) · Massachusetts

Effective Current approved utility rate schedule and tariff; credit inputs change by billing period.

Eversource identifies its Massachusetts Net Metering Tariff, Schedule Z, and interconnection application as the governing documents; Eversource serves regulated Massachusetts customers covered by the DPU program.

Source: eversource.com

Full Eversource (MA) detail →

Massachusetts retains retail-style net metering for customers of the DPU-regulated distribution companies Eversource, National Grid (Massachusetts Electric and Nantucket), and Unitil. Standard credits generally equal 100% of applicable per-kWh basic-service, distribution, transmission, and transition charges; new solar facilities and certain cap-exempt behind-the-meter facilities receive market credits generally equal to 60% of those charges, with specified public-entity exceptions at 100%. SMART is a separate DOER incentive program and its alternative on-bill credits cannot be generated at the same time as net metering credits. Municipal light plants are outside DPU jurisdiction and set their own rules.

Program details

Compensation mechanismRetail-style net metering credits under 220 CMR 18.00 and utility tariffs. Standard solar credits are generally 100% of the applicable basic service, distribution, transmission, and transition kWh charges; new solar and qualifying cap-exempt serving-on-site-load facilities generally receive 60% market net metering credits, while qualifying municipal/governmental facilities can receive 100% market credits. SMART incentive payments are separate from net metering; a facility cannot generate SMART alternative on-bill credits and net metering credits simultaneously.
mass.gov · mass.gov · mass.gov
Export rateNo single statewide dollar-per-kWh rate. For ordinary qualifying solar, the standard credit is 100% × excess kWh × (basic service + distribution + transmission + transition charges); for new solar and qualifying cap-exempt serving-on-site-load facilities, the market credit is generally 60% × excess kWh × those same charges. Qualifying municipal/governmental new-solar facilities receive 100% of those charges. Rates vary by utility, rate class, ISO-NE load zone, and time of use.
mass.gov · nationalgridus.com · unitil.com
Rate effectiveThe applicable utility tariff and current utility rate schedule in effect for each billing period; the cited National Grid net-metering tariff is M.D.P.U. No. 1625 effective March 1, 2026, and the Unitil Schedule NM is the utility tariff governing its credits. Credit inputs change with approved basic-service and delivery rates.
nationalgridus.com · unitil.com · mass.gov
Credit rolloverUnused net metering credits carry forward from billing period to billing period; DPU says credits generally never expire. A cap-exempt facility serving on-site load is instead subject to the annual cash-out/carry-over rule described below.
mass.gov · mass.gov
Credit expirationCredits generally never expire. The principal exception is a cap-exempt facility serving on-site load, for which credits are cashed out or carried over at the end of the annual April-through-March period at the utility's avoided-cost rate.
mass.gov · mass.gov
Annual true-upNo annual true-up for ordinary net-metered facilities; balances roll forward. For a cap-exempt facility serving on-site load, the annual reconciliation/cash-out occurs at the end of March for the April-through-March period.
mass.gov
Residential system capClass I solar: 60 kW or less. Nameplate cap-exempt renewable Class I facilities are eligible at 25 kW AC or less; larger eligible renewable facilities can qualify as cap-exempt serving on-site load if they meet the post-2021 interconnection and on-site-load requirements.
mass.gov · mass.gov
Commercial system capPrivate solar: Class II is more than 60 kW through 1 MW; Class III is more than 1 MW through 2 MW. Public solar may be up to 10 MW aggregate per municipality or governmental entity, with Class III public facilities up to 10 MW per facility under the class definition.
mass.gov · mass.gov
Aggregate program capGeneral-program caps are utility-territory-specific and split into private (7% of highest historical peak load) and public (8%) allocations. As of December 2024: Eversource 408.24 MW private / 466.56 MW public; National Grid Massachusetts Electric 359.191 / 410.504 MW; National Grid Nantucket 4.069 / 4.650 MW; Unitil 7.167 / 8.191 MW. Cap-exempt facilities are excluded from aggregate-cap calculations.
mass.gov · mass.gov
Program statusThe DPU guide publishes the general-program caps as of December 2024 but does not state that all four utility territories' caps are reached. New non-cap-exempt projects must obtain a MassACA cap allocation; cap-exempt facilities can net meter even when the relevant cap is full. MassACA is the live source for current connected/requested capacity and remaining space.
mass.gov
RegulatorMassachusetts Department of Public Utilities (DPU)
mass.gov
DocketD.P.U. 23-140 (open net-metering rulemaking); D.P.U. 23-140-B is the approved transition plan for cap-exempt reclassification/applications. D.P.U. 25-117 is an open investigation into expanding access to net-crediting solutions.
mass.gov · nationalgridus.com · mass.gov
Governing ruleG.L. c. 164, §§ 138-140; 220 CMR 18.00; and each DPU-approved utility net-metering tariff. The current National Grid provision is M.D.P.U. No. 1625; Unitil uses Schedule NM; Eversource provides its DPU-approved Massachusetts Net Metering Tariff.
mass.gov · nationalgridus.com · unitil.com · eversource.com
GrandfatheringA solar facility that is not a new solar facility generally receives standard credits for 25 years from the date it was first authorized to interconnect; after 25 years it receives market credits. Facilities with cap allocations under the pre-September 26, 2016 regime and granted by January 8, 2017 have the statutory historical treatment described in the utility tariffs; nameplate cap-exempt facilities are not subject to the same cap-allocation requirement.
mass.gov · nationalgridus.com
Interconnection applicationApply for interconnection with the relevant distribution company under its DPU-approved interconnection tariff and indicate the request for net metering on that application. Non-cap-exempt projects must secure a MassACA/System of Assurance cap allocation before construction; the host customer submits Schedule Z for credit allocation.
eversource.com · nationalgridus.com · mass.gov
Interconnection timelineTiered Company Business Day limits under the filed Massachusetts interconnection tariff: Expedited Process total maximum 45 days (65 days if Supplemental Review is required), and Standard Process total maximum 135 days (160 days if the application starts in the Expedited process). The tariff also establishes Simplified and Standard Complex processes, and time frames may be extended by mutual agreement.
nationalgridus.com
Pending changeD.P.U. 25-117 remains open and created a limited-time process allowing accrued net metering/AOBC balances to be transferred through December 31, 2026; the DPU guide says the same allocation limits apply. D.P.U. 23-140 remains open as the net-metering rulemaking, and D.P.U. 25-175 is an open utility filing to implement SMART 3.0 and revised SMART tariffs. No DPU move to statewide net billing replacing net metering was verified; the current rules continue to provide net-metering credits.
mass.gov · mass.gov · mass.gov

Rates by utility

State rules set the framework. Individual utilities often pay something different, and where they do the utility tariff governs.

Eversource Energy (NSTAR/WMECo)Formula varies by customer/facility: standard solar generally 100% of applicable basic-service + distribution + transmission + transition kWh charges; new solar generally 60% market credit; qualifying public-entity cases can receive 100%.
Current approved utility rate schedule and tariff; credit inputs change by billing period.
Eversource identifies its Massachusetts Net Metering Tariff, Schedule Z, and interconnection application as the governing documents; Eversource serves regulated Massachusetts customers covered by the DPU program.
eversource.com · mass.gov
National Grid (Massachusetts Electric and Nantucket Electric)Formula varies by customer/facility: standard solar generally 100% of applicable basic-service + distribution + transmission + transition kWh charges; new solar generally 60% market credit; qualifying public-entity cases can receive 100%.
M.D.P.U. No. 1625 effective March 1, 2026; rate inputs vary by billing period and service territory.
Current filed Net Metering Provision covers Massachusetts Electric Company and Nantucket Electric Company and sets the standard, 60% market, and 100% market credit formulas.
nationalgridus.com
Unitil (Fitchburg Gas and Electric Light Company)Formula varies by customer/facility: standard solar generally 100% of applicable basic-service + distribution + transmission kWh charges; new solar generally 60% market credit; qualifying public-entity cases can receive 100%.
Schedule NM tariff currently fetched; credit inputs vary by billing period and customer rate class.
Unitil's Schedule NM applies the Massachusetts net-metering rules, including the 25-year standard-credit period, 60% market-credit formula for new/non-cap-exempt solar, and carry-forward of balances.
unitil.com
Municipal light plants (M.L.P.s)Not set by the DPU statewide net-metering tariff; each municipal light plant sets its own customer/export-credit rules.
Utility-specific; not verified here.
The DPU guide's statewide eligibility statement is for regulated electric companies (Eversource, National Grid, and Unitil); municipal light plants are outside DPU jurisdiction.
mass.gov

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