Grid & off-grid

Net metering calculator, Massachusetts

Enter your exact usage, system size, and rate details to see how Massachusetts's net metering policy affects your solar bill, with precise controls for season, tiered rates, and fixed fees.

Your numbers

1 Project details Optional
Shown on your exported report. Leave blank to skip.
2 Your usage and system
Find this on a recent utility bill, usually labeled kWh used.
Use your quoted or planned system size. Panel count times panel wattage divided by 1,000 gives a rough figure.
Solar production swings seasonally; pick a specific month type to see how your bill shifts.
Most utilities charge a flat customer or connection fee regardless of usage.
3 Your location and rate
Defaulted to Massachusetts's average peak sun hours. Adjust if you know your local figure.
Defaulted to Massachusetts's current average residential rate. Your utility's actual rate may differ.
Massachusetts typically credits exports around 100% of retail. Full retail net metering plus SMART program production-based incentive payments.
Some utilities charge progressively higher per-kWh rates as monthly usage climbs into higher tiers.
Accounts for inverter loss, wiring loss, dust, and temperature derate combined.
Informational only. A monthly cycle means unused export credit does not carry to the next bill; annual and rolling cycles do.

How it works

Three steps to your Massachusetts solar bill estimate

Step 1

Enter your usage, system size, and season

Pull your monthly kWh from a recent bill and enter your planned or quoted system size in kW. If you only know your panel count, multiply it by each panel's wattage and divide by 1,000 to get a kW figure first. Select a season to model a specific month rather than only an annual average.

Step 2

Confirm your rate, tier, and export credit

Massachusetts's typical residential rate and export credit level are filled in by default. Swap in your utility's actual tariff numbers, tier bracket, and fixed monthly fee if you have a recent bill or interconnection agreement showing them.

Step 3

Compare the result to a full retail scenario

Run the net billing vs net metering comparison tool to see exactly how much Massachusetts's current export credit rate costs you compared to full 1:1 retail crediting.

How net metering works in Massachusetts

Full retail net metering, stacked with a separate production incentive

Massachusetts credits solar exports at the full retail rate through standard net metering, and then layers a second, entirely separate incentive on top: the SMART program (Solar Massachusetts Renewable Target). SMART pays a flat per-kWh rate for everything your system produces, rather than only the exported portion, a different mechanism from a renewable energy certificate sale, currently $0.03/kWh for residential systems up to 25 kW, locked in for 20 years once you enroll, or $0.06/kWh for qualifying low-income households.

SMART recently went through a major redesign

The Massachusetts Department of Public Utilities approved SMART 3.0 on May 19, 2026, changing the program from a fixed "declining block" rate structure, where incentive rates dropped in tiers as capacity filled, to one where the state's Department of Energy Resources adjusts rates, capacity allocations, and program features annually based on current market data.

Adders can meaningfully increase the SMART payment

On top of the base rate, SMART offers bonus payments called adders for specific project types: pairing your system with battery storage adds roughly $0.04/kWh, and a building-mounted (rather than ground-mounted) installation adds about $0.03/kWh; Massachusetts's tax credit and rebate estimator can help you see how these stack against other available incentives. These stack, so a residential system with storage can earn a meaningfully higher blended rate than the base incentive alone.

Utility choice affects your net metering credit value

Massachusetts' rules apply statewide, but the exact credit value can differ by utility, since transmission and distribution charge treatment varies between Eversource, National Grid, and Unitil. Confirming your specific utility's current net metering terms alongside your SMART enrollment gives the most accurate combined savings picture. The glossary entry for renewable energy certificate spells out what that term means here.

Interconnection and the off-grid comparison

Connecting a system still requires standard utility review before it can operate, on top of any separate SMART program enrollment; the grid interconnection cost estimator covers what that process typically costs. And with full retail net metering plus a stacked production incentive already in place, the case for going fully off-grid in Massachusetts is weak; the grid tie vs off grid comparison tool shows how much more an off-grid system would cost.

Questions If your utility credits exports at less than the retail rate, storing power can beat exporting it. The battery storage size calculator in our Battery & Storage section can help you size a battery for that.

Frequently asked

Massachusetts credits exports at the full retail rate, roughly 30 cents/kWh and still climbing, through standard net metering, then stacks a separate SMART program payment of $0.03/kWh on all production, locked for 20 years, on top.

The average residential rate in Massachusetts was about 30 cents per kWh as of mid-2026, per EIA data, among the highest in the nation and still rising. Full retail net metering applies statewide, and the separate SMART incentive program pays an additional per-kWh rate on all production.

No, SMART stacks on top of standard net metering rather than replacing it. SMART pays a flat per-kWh rate, currently $0.03/kWh for most residential systems, on everything your system produces, locked in for 20 years, while you separately earn full retail-rate net metering credit for whatever you export.

The Massachusetts DPU approved SMART 3.0 on May 19, 2026, moving the program away from a fixed declining-block rate structure toward one where the state adjusts incentive rates and capacity allocations annually based on current data, rather than locking in a schedule years in advance.

Related tools

Compare Massachusetts's policy to other structures

Grid tie vs off grid comparison Net billing vs net metering Buy all sell all vs net metering Avoided cost rate calculator Grid export cap calculator Grid interconnection cost estimator Grid tie with battery backup comparison All grid and off-grid tools