Net metering & export compensation
M.G.L. c. 164 § 138-140. Class I (≤10 kW single-phase / 25 kW three-phase) has no cap and gets retail credit.
Interconnection process
DPU Standards for Interconnection of Distributed Generation; simplified path for inverter ≤15 kW.
Permitting & inspection
Local wiring inspector under the Massachusetts Electrical Code (NEC with MA amendments).
Utilities operating in this state
Eversource, National Grid, Unitil, plus municipal light plants (Concord, Belmont, Taunton, etc.).
Electrical code (NEC) considerations
The U.S. National Electrical Code (NEC) does not have a listed pathway for backfeeding a standard 120 V receptacle from a solar inverter. Article 705 covers interconnected power production sources and generally expects a dedicated, breakered, labeled circuit. Many AHJs that follow NEC 2017/2020/2023 will not approve a cord-and-plug PV connection on that basis, regardless of state policy.
HOA, landlord & solar access
Check your lease, HOA covenants, and condo rules. Many states have a 'solar access' or 'solar rights' law that limits HOA restrictions on rooftop PV, but those statutes were written for permanent installations and rarely mention plug-in or balcony kits explicitly. Renters almost always need written landlord permission.
Official sources to consult
- DSIRE — state policies & incentives
- Mass DPU
- SMART program
- Your specific utility's interconnection application and net metering / net billing tariff
- Your local building department (the AHJ that will inspect any work)
Bottom line for plug-in solar buyers in Massachusetts
Even where state policy is favorable, U.S. utilities and inspectors generally do not recognize a cord-and-plug PV connection. If you want to be fully code-compliant and earn export credits, plan on a permitted, hard-wired install by a licensed electrician with a signed interconnection agreement. Off-grid uses (running a single appliance, charging a battery, RV/shed power) avoid most of these rules but still need to follow product instructions and basic electrical safety.