Massachusetts Solar Calculator — 2026 Costs & Payback
Massachusetts has the highest electricity rates in the contiguous US ($0.31/kWh average residential), full net metering, the SMART production incentive, and a 15% state tax credit (capped at $1,000). Payback is consistently 5–7 years — among the fastest in the country despite low irradiance (1,245 kWh/kW).
US Solar Payback Calculator — 2026
Get an accurate solar payback estimate for your state using NREL solar irradiance, EIA electricity rates, and the 30% federal Investment Tax Credit.
The numbers above are based on state averages. Real quotes vary by roof orientation, shading, panel type, and installer. Compare quotes from 3+ pre-vetted installers in your area — free, no obligation.
Highest electricity rates in the lower 48. NEM 3.0 (since April 2023) cuts export rates ~75%. Battery storage now near-mandatory for payback.
Methodology & sources
Solar irradiance per state: National Renewable Energy Laboratory (NREL) PVWatts PSM3 typical-year data, weighted state average for residential rooftops.
Electricity rates: EIA Form 826 monthly residential rates (most recent September 2025 data).
Federal ITC: 30% through 2032 under the Inflation Reduction Act (Section 25D).
State incentives: DSIRE (Database of State Incentives for Renewables & Efficiency) as of April 2026.
Inflation assumptions: 2.5% annual electricity price increase (EIA AEO 2024 reference case), 0.5% annual panel degradation (NREL standard).
Self-consumption assumption: 45% direct self-consumption without battery — typical for residential without storage.
Deep dive — solar in Massachusetts
Net metering: Full retail-rate for residential systems under 25 kW.
State tax credit: 15% of system cost up to $1,000. Stackable with 30% federal ITC.
Major utilities: Eversource, National Grid, Unitil, municipal lights — all participate in SMART and offer full net metering.
Battery in MA: State has the SMART battery adder (up to $0.07/kWh extra) and the Connected Solutions program (peak demand response, $200–$400/kW/year).
Massachusetts solar FAQ
What is SMART in Massachusetts solar?
Solar Massachusetts Renewable Target — production-based incentive paying a fixed $/kWh tariff for 10 years. Block-based system with declining rates over time.
How much is the Massachusetts state solar tax credit?
15% of system cost up to $1,000. Stacks with 30% federal ITC.
Does Massachusetts have net metering?
Yes — full retail-rate net metering for residential systems under 25 kW.
Why is Massachusetts solar payback so fast despite low irradiance?
Highest electricity rates in the contiguous US ($0.31/kWh) plus SMART program plus state tax credit plus full net metering. Even with modest production, the savings per kWh are exceptional.