Solar Calculator for Maine: Costs, Incentives & ROI
Maine's residential solar market is defined by one of the most compelling rate environments in the continental United States: at approximately twenty-five cents per kilowatt-hour, Maine's residential electricity rates are the highest of any state in the lower forty-eight — exceeded only by Hawaii — fundamentally transforming solar economics for Maine homeowners. When each kilowatt-hour of solar generation offsets electricity that would otherwise cost twenty-five cents, payback periods compress dramatically relative to states with lower rates, making Maine's solar value proposition particularly strong despite its more modest solar resource. Maine's net energy billing program — NEB, distinct from the traditional net metering terminology used in most other states — compensates residential solar customers for exported generation at the full retail electricity rate, with monthly credits rolling forward up to twelve months before expiring. Maine transitioned to Net Energy Billing in 2019 under Maine PUC Docket 2019-00179, and retail-rate compensation was reaffirmed for residential customers under LD 1981 (2023). Central Maine Power, an Avangrid subsidiary, serves approximately seventy-eight percent of Maine's residential customers across southern and central Maine including Portland and Lewiston. Versant Power, successor to Bangor Hydro-Electric and Maine Public Service, serves northern and eastern Maine including Bangor and Aroostook County. Maine's incentive framework combines the federal Investment Tax Credit of thirty percent, a full property tax exemption under 36 M.R.S. § 656 for renewable energy equipment, and a full sales tax exemption under 36 M.R.S. § 1760(45) — together making Maine's policy environment among the most supportive in New England.
Incentive data updated: May 2026(may be outdated)
Average Solar Cost in Maine
Average installed solar costs in Maine typically range from approximately three dollars and ten cents per watt before incentives, reflecting New England's higher labor costs, the logistics of installation in a geographically dispersed state with long winters, and the cold-weather considerations that affect structural and electrical design for rooftop systems in northern climates. A standard six-kilowatt residential system costs between eighteen thousand and twenty thousand dollars before the federal Investment Tax Credit — modestly above neighboring Connecticut. The thirty-percent ITC reduces the net installed cost to approximately twelve thousand six hundred to fourteen thousand dollars for a six-kilowatt system, with the full sales tax exemption under 36 M.R.S. § 1760(45) saving approximately six percent on the full system cost — an additional eleven hundred to twelve hundred dollars in tax savings that reduces the effective installed cost before the ITC is applied. The property tax exemption under 36 M.R.S. § 656 is a full, one-hundred-percent exemption: the complete assessed value increment that a solar installation adds to a residential property is excluded from local property tax calculations for the life of the system. Unlike states with partial exemptions or local-option arrangements, Maine's property tax exemption applies statewide to all residential solar photovoltaic systems and qualifying battery storage, without requiring a separate local application.
- Avg. installed cost
- $3.10/W
- Typical 6 kW system
- $18,000–$20,000
Top Solar Incentives in Maine
Live incentive data not currently available for Maine. See the federal incentive guidance via our Solar Tax Credit Calculator.
Electricity Rates in Maine
Maine residential electricity rates average approximately twenty-five cents per kilowatt-hour on a blended basis, the highest of any state in the continental United States and among the highest in North America. Central Maine Power customers in southern and central Maine — the majority of the state's residential solar market — face electricity costs driven by a combination of the standard offer supply rate, CMP's delivery and distribution charges, renewable portfolio standard compliance costs, and transmission charges associated with Maine's grid connection to the broader New England grid operated by ISO New England. Versant Power customers in northern and eastern Maine pay comparable blended rates in the twenty-two to twenty-five cent range. Maine's high electricity rates are attributable to a combination of the state's relative grid isolation — Maine is at the northeastern end of the New England transmission system — cold winters that drive high heating demand on the grid, the state's renewable portfolio standard obligations, and the absence of large baseload generation resources within the state. For solar customers, the twenty-five-cent rate environment means that every kilowatt-hour of solar generation self-consumed or credited under NEB offsets electricity that would otherwise cost approximately twice what a homeowner in a moderate-rate state like North Carolina or Minnesota would pay — fundamentally accelerating payback and increasing lifetime system value.
Peak Sun Hours in Maine
Maine's solar resource is more modest than southern New England neighbors but remains economically viable given the state's exceptional electricity rate environment. The Portland metropolitan area in southern Maine averages approximately four and two-tenths to four and a half peak sun hours per day on a south-facing tilted surface — comparable to the Boston metropolitan area. Lewiston and Auburn, situated inland, benefit from slightly more consistent sun exposure, averaging approximately four to four and a half peak sun hours per day. Bangor and the Penobscot Bay coast average approximately three and eight-tenths to four and two-tenths peak sun hours, reflecting the Gulf of Maine's influence on cloud cover. Northern Maine communities in Aroostook County receive approximately three and a half to four peak sun hours per day. Maine's cold winter temperatures are a meaningful advantage: solar panels generate more power per watt when cool, partially offsetting the shorter winter day length. A six-kilowatt system in the Portland area typically produces approximately six thousand eight hundred to seven thousand two hundred kilowatt-hours per year. While annual production is lower than Sun Belt states, each kilowatt-hour carries far greater financial value at Maine's twenty-five-cent rate — yielding approximately seventeen hundred dollars in annual savings and a payback period of approximately seven years.
Example ROI for a 6 kW System
- Estimated annual savings
- $1,700
- Payback period
- 7.0 years
- 25-year net savings
- $36,000
Run a personalized estimate with your ZIP code using the Solar ROI Calculator.
Major Cities in Maine
- Portland04101
- Lewiston04240
- Bangor04401
- South Portland04106
- Auburn04210
Common Questions About Solar in Maine
Why is solar so financially attractive in Maine's 25-cent electricity rate environment?
Maine's residential electricity rate of approximately twenty-five cents per kilowatt-hour — the highest in the continental United States — fundamentally transforms the economics of rooftop solar compared to lower-rate states. When each kilowatt-hour of solar generation offsets electricity that would otherwise cost twenty-five cents, a six-kilowatt system producing roughly seven thousand kilowatt-hours per year displaces approximately seventeen hundred dollars of annual electricity cost — versus approximately nine hundred dollars for the same system in North Carolina at thirteen cents per kilowatt-hour. The high-rate environment compresses payback periods dramatically: a well-sized Maine system with a net installed cost of approximately twelve thousand to thirteen thousand dollars after the thirty-percent federal ITC can recover its cost in approximately seven years, compared to nine to ten years in a moderate-rate state. Over a twenty-five-year system life, the cumulative savings compound significantly: at Maine's rates, a Portland homeowner can expect approximately thirty-six thousand dollars or more in net lifetime savings. The combination of high electricity rates, Maine's full property tax exemption, full sales tax exemption, and the Net Energy Billing program's retail-rate compensation for exported generation makes Maine one of the most economically compelling solar markets in the country outside of Hawaii.
What is Maine's Net Energy Billing (NEB) program and how does it differ from net metering?
Maine's Net Energy Billing program — NEB — is the state's mechanism for compensating residential solar customers for generation exported to the grid, and it functions similarly to traditional net metering in most respects but uses different terminology and has evolved through several regulatory proceedings. Maine transitioned from kilowatt-hour-based net metering to NEB in 2019 under Maine PUC Docket 2019-00179, and the legislature reaffirmed retail-rate NEB compensation for residential customers through LD 1981, enacted in 2023. Under NEB, excess solar generation that is not consumed in real time is credited to the customer's account at the full retail electricity rate — approximately twenty-five cents per kilowatt-hour for CMP customers — and those credits roll forward from month to month for up to twelve months before expiring. This twelve-month credit rollover means that summer solar surpluses effectively bank credits that can be drawn down during Maine's lower-solar winter months, smoothing the financial benefit across the year. Central Maine Power administers NEB under its standard tariff for the majority of Maine residential customers; Versant Power operates a comparable program in northern and eastern Maine. Maine homeowners evaluating solar should verify current NEB program terms directly with their utility, as the Maine PUC actively reviews the program and future modifications are possible as the state's distributed generation penetration grows.
Are solar panels and installation exempt from Maine sales tax?
Yes. Maine exempts solar energy equipment and installation from state sales tax under 36 Maine Revised Statutes § 1760(45). This exemption applies to solar photovoltaic panels, inverters, racking and mounting hardware, wiring, and other equipment integral to the solar energy system. The sales tax exemption also extends to battery storage systems when installed as part of or in conjunction with a residential solar installation. Maine's standard state sales tax rate of five and a half percent applies broadly to tangible personal property, so the solar equipment exemption represents a meaningful reduction in effective installed cost — approximately nine hundred to eleven hundred dollars in sales tax savings on a six-kilowatt residential system priced between eighteen thousand and twenty thousand dollars. In addition to the sales tax exemption, solar energy equipment is fully exempt from residential property tax assessment under 36 M.R.S. § 656, meaning the increment in home value attributable to a solar installation is entirely excluded from property tax calculations. The combination of the sales tax exemption and the property tax exemption reduces the total cost of solar ownership in Maine relative to states that do not offer both incentives.
Do I need a Master Electrician or special license for solar installation in Maine?
Yes. Maine requires that electrical work associated with solar photovoltaic installations — including inverter wiring, AC disconnect, utility interconnection, and metering work — be performed by or under the direct supervision of a licensed Master Electrician or Journeyman Electrician holding a valid Maine license issued by the Maine Electricians' Examining Board, administered through the Maine Office of Professional and Occupational Regulation. Maine law prohibits unlicensed electrical work, and solar installations include substantial electrical components that fall squarely within the licensing requirement. The distinction between Master and Journeyman status matters for supervision: a Journeyman Electrician may perform the electrical work but must be supervised by a Master Electrician. Most reputable Maine solar contractors maintain Master Electrician credentials on staff or hold contractor licenses that cover the full scope of solar installation work. Before signing a contract, verify that your installer's electricians hold current Maine licenses searchable at maine.gov/pfr/professionallicensing/. NABCEP certification is an additional quality credential beyond the state licensing minimum. Requesting proof of Maine electrical licensing and at least three competitive quotes is recommended practice for Maine homeowners.
Best Solar Installers in Maine
Maine requires that all electrical work associated with solar photovoltaic installations — including inverter wiring, AC disconnect, utility interconnection, and metering — be performed by or under the direct supervision of a licensed Master Electrician or Journeyman Electrician holding a valid Maine license from the Maine Electricians' Examining Board, administered through the Maine Office of Professional and Occupational Regulation. Verify your installer's electricians hold current Maine electrical licenses using the lookup tool at maine.gov/pfr/professionallicensing/. NABCEP certification is an additional national quality indicator beyond the Maine state licensing minimum, demonstrating that installers have met rigorous solar PV competency and experience standards. Requesting at least three competitive quotes from licensed, NABCEP-credentialed installers is recommended practice for Maine homeowners.
- Get at least 3 quotes from different installers to compare pricing and equipment.
- Check installer ratings with the BBB before signing a contract.
- Verify contractor licensing with Maine Electricians' Examining Board — Master Electrician or Journeyman Electrician license required for all PV electrical work (Maine Office of Professional and Occupational Regulation; administered under Maine Department of Professional and Financial Regulation). Ask for proof of a 20–25 year panel warranty.
Top Utility Companies in Maine
Central Maine Power (CMP; Avangrid)
Service area: Portland, Lewiston, Auburn, South Portland, Biddeford, Augusta, Waterville, southern and central Maine
Tariff: tier-2, TOU
Residential rate: 23.0–26.0¢/kWh (as of 2026-05)
NEM program: Maine NEB — Net Energy Billing at full retail rate; 12-month credit rollover (Maine PUC Docket 2019-00179 + LD 1981 2023 retail-rate reaffirmation)
Versant Power
Service area: Bangor, Brewer, Orono, Old Town, Presque Isle, Houlton, northern and eastern Maine
Tariff: flat
Residential rate: 22.0–25.0¢/kWh (as of 2026-05)
NEM program: Maine NEB — Net Energy Billing at full retail rate; 12-month credit rollover; Versant Power successor to Bangor Hydro-Electric + Maine Public Service
Net Metering Policy in Maine
- Version
- NEM transition
- Effective date
- 2019-04-01
- Buyback rate
- retail
- System size cap
- 660 kW
- Grandfathering
- NEB program ongoing; residential retail-rate compensation reaffirmed by LD 1981 (2023); future program modifications tracked through Maine PUC Docket 2019-00179; no current grandfathering cutoff date announced
Maine Net Energy Billing (NEB) credits excess generation at full retail electricity rate (~25¢/kWh for CMP customers); 12-month credit rollover then expiration. Program transitioned from kWh-based net metering to NEB under Maine PUC Docket 2019-00179 (2019); retail-rate compensation reaffirmed for residential customers by LD 1981 (2023). Fresh SEO opportunity — 'Net Energy Billing' and 'NEB' terminology relatively new vs traditional NEM; lower keyword competition. Future Maine PUC revisions possible as distributed generation penetration grows.
Property Tax Exemption in Maine
- Status
- full
- Exemption
- 100%
- Applies to
- solar-pvstorage
36 M.R.S. § 656 — renewable energy equipment fully exempt from residential property tax assessment; solar PV system value increment is entirely excluded from local property tax calculations. Battery storage systems are also covered. Solar equipment is additionally exempt from Maine 5.5% state sales tax under 36 M.R.S. § 1760(45). Combined with ~25¢/kWh retail rate and full-retail NEB compensation, Maine offers some of the highest solar ROI in the United States outside Hawaii.