Maine Plug-In Solar Law: What LD 1730 Does

Maine became the second US state to legalize plug-in solar on April 6, 2026, when Governor Janet Mills signed LD 1730. The law takes effect July 2026.

Maine followed Utah’s lead by nine months with a law that closely mirrors the Utah model: 1,200W limit, no utility pre-approval required, no interconnection fees. What distinguishes Maine from Utah economically is the electricity rate. At 27.9¢/kWh, Maine has nearly two and a half times Utah’s rate, which means the same plug-in solar system saves significantly more money in Maine.

See Maine's full plug-in solar law details and estimated annual savings at Maine's rates.

Maine solar law details →

What LD 1730 does

LD 1730 creates a separate regulatory category for plug-in solar devices in Maine. The provisions:

1,200W cap. Systems up to 1,200W qualify. A two-panel 400W x 2 setup with a 800W microinverter is the most common kit that fits this limit.

No utility pre-approval. Central Maine Power and Versant Power cannot require interconnection applications or charge fees for qualifying systems.

Renter protections. Landlords cannot prohibit qualifying plug-in solar installations. Reasonable placement restrictions are permitted.

No net metering. Like other enacted states, LD 1730 exempts plug-in systems from the interconnection process by also exempting them from net metering. Any electricity exported to the grid is not compensated. Size to consume, not to export.

Maine’s high rates make the economics clear

Maine at 27.9¢/kWh has the second-highest electricity rate among New England’s enacted states (behind Connecticut at 28.6¢/kWh). Portland averages about 4.3 peak sun hours per day; Bangor is similar. Summer sun hours in July–August run higher, around 5.2–5.5 hours.

For an 800W south-facing system in Portland:

800W x 4.3h x 0.85 = 2.92 kWh/day production At 70% self-consumption: 2.04 kWh/day At 27.9¢/kWh: $0.57/day, or $208/year

A $900 kit pays back in about 4.3 years. For a renter who plans to stay in their apartment for three or more years, the math is straightforward.

Maine’s rate trajectory also matters. Central Maine Power customers have seen consistent rate increases over the last five years. A fixed capital investment in plug-in solar benefits from rising rates, since each kilowatt-hour it offsets is worth more over time.

The July 2026 effective date

LD 1730’s effective date is in July 2026. The specific date depends on when the law was published in the Maine Revised Statutes, but landlord protections and utility restrictions are in effect for the summer installation season.

For renters who want to get a system in before August, when Maine summer sun is at its peak, timing aligns well. A mid-July install catches six to eight weeks of high-production summer sun before the fall equinox.

Maine housing context

Maine’s population is largely rural, but Portland, Lewiston-Auburn, Bangor, and Augusta have meaningful renter populations. Portland in particular has high rental rates and among the highest electricity costs in the state (Central Maine Power rates in southern Maine can run 5–8% above the statewide average).

For Maine homeowners, a plug-in supplement to existing solar or heating systems is increasingly attractive. Maine has above-average heat pump adoption driven by state efficiency programs. A plug-in system that offsets some of the electricity drawn by a heat pump shortens payback for both investments.

The plug-in solar readiness checker includes Maine’s law status and July effective date.

Check your Maine home or apartment's readiness for a plug-in solar install under LD 1730.

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