Plug-in solar in Maine
Maine's plug-in solar law is now in effect. It uses two tiers based on combined inverter output rather than one flat power limit, and the tier decides whether this statute requires a Maine-licensed electrician and utility notification.
What do Maine's 420 W and 1,200 W limits measure?
Both figures are combined inverter output: the AC power the system's inverters can send into the building, not the total rating of the panels. A kit's panels can add up to more than its inverter output, so the wattage in a product name like an "800 W solar kit" is not necessarily the number to compare against Maine's tiers.
See how panel wattage and inverter output differ →
When does Maine require a licensed electrician?
Only in the higher tier. Up to 420 W of combined inverter output, no electrician is required. Above 420 W and up to 1,200 W per service address, Maine's law requires a dedicated circuit with a single outlet and installation by an electrician licensed in Maine.
Do you need to tell your utility?
Not for a system of 420 W or less. Above 420 W, the customer must notify the transmission and distribution utility within 30 days of installing the system, giving the service address, the inverter capacity and confirmation that the system complies.
What certification does Maine require?
The device must be listed or certified in accordance with UL 3700, the Outline of Investigation for Interactive Plug-in Photovoltaic Equipment and Systems, or to a comparable standard from a nationally recognized testing laboratory.
Example: 400 W of combined inverter output falls in the lower-power tier. 800 W of combined inverter output falls in the higher-power tier, where Maine's law requires a dedicated circuit with a single outlet, a Maine-licensed electrician and utility notification within 30 days.
How Maine differs
Maine does not use the single 1,200 W route found in several other enacted state laws. It sets a lower tier up to 420 W and a second tier above 420 W through 1,200 W, and the higher tier adds both a Maine-licensed-electrician requirement and utility notification within 30 days.
Compare plug-in solar rules by stateLD 1730 (S.P. 676); Public Law 2026, Chapter 644. Last checked August 28, 2026.
Also check landlord or HOA rules, local code, utility requirements outside this statute, and product instructions where relevant.