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Maine solar at a glance
Estimates use the inputs above and the assumptions in our methodology: Maine net metering: exports credited at the retail rate (statewide rule; your utility's tariff may differ). Prices rise 2.5% a year; panels lose 0.5% a year.
Solar cost in Maine by system size
Same assumptions as the typical home above; only the system size changes. Prices are the state median before incentives and include the incentives our calculator applies by default in Maine.
| System | Price before incentives[3] | After incentives | kWh in year 1[2] | Year-1 savings[4][5] | Payback (years) |
|---|---|---|---|---|---|
| 4 kW | $14,400 | $14,400 | 5,280 | $1,590 | 8 |
| 6 kW | $21,600 | $21,600 | 7,910 | $2,000 | 10 |
| 8 kW | $28,800 | $28,800 | 10,550 | $2,000 | 13 |
| 10 kW | $36,000 | $36,000 | 13,190 | $2,000 | 15 |
| 12 kW | $43,200 | $43,200 | 15,830 | $2,000 | 18 |
Incentives that lower the price in Maine
Business credit for leased and PPA systems (48E)
Claimed by the system owner, not the homeowner; solar must begin construction by July 4, 2026 or be in service by December 31, 2027[6]
If a company owns the panels on your roof (a lease or power purchase agreement), that company may claim the business clean electricity investment credit and can reflect it in your price. You cannot claim it yourself.
- Who
- Third-party-owned systems (leases and PPAs). Ask the provider whether the price assumes this credit.
- Deadline
- December 31, 2027
- Checked
- November 5, 2026
Solar Energy Equipment Property Tax Exemption
Solar equipment that generates heat or electricity is exempt from local property tax (100% of the equipment's value); owner must file a report with the assessor by April 1 of the first year claimed[7]
For tax years from April 1, 2025: solar equipment whose energy is all used on site, or that is collocated with net energy billing customers subscribed to at least 50% of its output (rooftop home systems qualify).
- Who
- For tax years from April 1, 2025: solar equipment whose energy is all used on site, or that is collocated with net energy billing customers subscribed to at least 50% of its output (rooftop home systems qualify).
- Deadline
- None set in the source
- Checked
- November 5, 2026
All Maine incentives, including utility and local programs →
How Maine utilities credit your solar
Maine's Net Energy Billing kWh Credit Program is open to all customers of Central Maine Power and Versant: each kWh your panels send to the grid offsets a kWh you buy, reducing both delivery and supply charges, and monthly surpluses bank as kWh credits for a rolling 12 months. Credits unused after 12 months expire without payment (their value goes to low-income assistance), and you still pay the monthly customer charge; the 2025 law (PL 2025 c. 430, LD 1777) closed new NEB agreements only for grid-side (community/front-of-meter) projects after Dec 31, 2025, leaving rooftop systems on the customer's side of the meter eligible.[5]
We have not added every Maine utility yet, so the estimates on this page use the state-level rule: Maine net metering: exports credited at the retail rate (statewide rule; your utility's tariff may differ).
Next steps
FAQ
Frequently asked questions
How much do solar panels cost in Maine?
How long does solar take to pay for itself in Maine?
Is there still a federal solar tax credit?
Not for homeowners who buy. The Federal Residential Clean Energy Credit (25D)[8] does not apply to systems whose installation is completed after December 31, 2025. Leased and PPA systems are different: the company that owns the system may still claim a business credit.
sources
[ 8 ]Every number on this page links to one of these sources. Dates show when we last checked each one.
- EIA Electric Sales, Revenue, and Average Price 2024, Table 5A: Residential average monthly bill by stateeia.gov · checked Nov 5, 2026
- NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)pvwatts.nlr.gov · checked Nov 5, 2026
- U.S. Distributed Solar and Storage 2026 Data Update (Barbose, Darghouth, O'Shaughnessy, Forrester), Berkeley Labeta-publications.lbl.gov · checked Nov 5, 2026
- EIA Electric Power Monthly, Table 5.6.B: Average price of electricity by state, year-to-date (August 2026, preliminary)eia.gov · checked Nov 5, 2026
- Central Maine Power - Frequently Asked Net Energy Billing Questions (read via Wayback Machine copy of 15 Jul 2026)cmpco.com · checked Nov 5, 2026
- Public Law 119-21 - Sec. 70513(a) and (g)(5) (48E); Sec. 70512(a) and (l)(4) (45Y)govinfo.gov · checked Nov 5, 2026
- Maine Revised Statutes Title 36, Section 656(1)(L) - Property tax exemptions (solar energy equipment)legislature.maine.gov · checked Nov 5, 2026
- IRS FS-2025-05: FAQs for modification of sections 25C, 25D, 25E, 30C, 30D, 45L, 45W, and 179D under Public Law 119-21 (OBBB)irs.gov · checked Nov 5, 2026
State data last re-checked November 5, 2026.
Change log
- Monthly output per kW in Portland updated to [80.5, 94.2, 124.0, 126.6, 141.2, 137.4, 141.4, 132.9, 120.5, 90.5, 67.9, 61.6] kWh/kW/month (NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)).
- Average solar radiation on the panels in Portland updated to 4.55 kWh/m2/day (NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)).
- Solar output per kW in Maine (PVWatts, Portland) updated to 1318.6 kWh/kW/yr (NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)).
- Solar Energy Equipment Property Tax Exemption: now "Solar equipment that generates heat or electricity is exempt from local property tax (100% of the equipment's value); owner must file a report with the assessor by April 1 of the first year claimed" (active).
- What the rule says updated to “Generated kWh will be applied against the kWh that you have consumed during the billing cycle. This will reduce the amount of energy that you buy from your electric supplier” (Central Maine Power - Frequently Asked Net Energy Billing Questions (read via Wayback Machine copy of 15 Jul 2026)).