National Grid (MA) solar export rate
What National Grid (MA) pays for power exported from rooftop solar in Massachusetts, with the source and the date it was checked.
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%.
National Grid (MA) · Massachusetts
Current filed Net Metering Provision covers Massachusetts Electric Company and Nantucket Electric Company and sets the standard, 60% market, and 100% market credit formulas.
Source: nationalgridus.com
Full National Grid (MA) detail →Massachusetts rules that apply to National Grid (MA)
The state framework sets the default. Where National Grid (MA) pays something different, the utility tariff governs and is what the card above reports.
| Compensation mechanism | Retail-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. |
|---|---|
| Export rate | No 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. |
| Rate effective | The 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. |
| Credit rollover | Unused 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. |
| Credit expiration | Credits 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. |
| Annual true-up | No 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. |
| Aggregate program cap | General-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. |
| Program status | The 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. |
| Grandfathering | A 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. |
| Regulator | Massachusetts Department of Public Utilities (DPU) |
| Governing rule | G.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. |
| Pending change | D.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. |
Other Massachusetts utilities
- Eversource (MA)Formula basedFormula varies by customer/facility: standard solar generally 100% of applicable basic-service
- Unitil (Fitchburg)Formula basedFormula varies by customer/facility: standard solar generally 100% of applicable basic-service
- MA municipal light plantsUnverifiedNot set by the DPU statewide net-metering tariff; each municipal light plant sets its own custo