Being honest about what's actually gone in Maine
No sales tax exemption, despite what some guides claim
Several widely circulated "Maine solar incentives" lists include a sales tax exemption that doesn't actually exist anymore. A narrow exemption did exist under 36 MRSA § 1760(96), but it was repealed effective December 31, 2016, which likely explains why older or unmaintained guides still mention one. Maine Revenue Services confirms the state's standard 5.5% sales tax now applies to solar equipment purchases with no solar-specific carve-out. On a typical $25,000 to $30,000 system, that adds roughly $1,400 to $1,700 in tax that some guides incorrectly suggest you'd avoid, so budget for it rather than being surprised on your final invoice. Check your federal ITC status too, since eligibility rules shifted heading into 2026, and understand the difference between Net Energy Billing and net metering before comparing Maine to other states. Use the sales tax exemption savings calculator to see what other states offer by comparison.
Full retail Net Energy Billing is the real driver
Net Energy Billing credits exported solar power at the full retail rate, essentially a 1:1 kilowatt-hour swap, with credits rolling over monthly for up to a year and trued up annually. This structure applies consistently across CMP, Versant, and smaller providers like Eastern Maine Electric Cooperative, and 2023 legislation that changed community solar compensation specifically left rooftop residential NEB untouched. Combined with Maine's above-average electricity rates, this remains one of the more valuable state-level solar mechanics in the Northeast.
The property tax exemption requires paperwork, and timing matters
Maine's solar property tax exemption, under 36 M.R.S. §§ 655(1)(U) and 656(1)(K), covers qualifying solar equipment, including panels, racking, inverters, and batteries used specifically to store solar-generated electricity, excluding it from local property tax assessment. Unlike some states where this happens automatically, Maine homeowners must file a written application with their local assessor, and per Maine Revenue Services' own Property Tax Bulletin No. 29, the deadline is April 1 of the first year you're claiming the exemption. That same bulletin notes a real timing trap: a system still under construction and not yet generating electricity or heat by April 1 doesn't qualify for that tax year at all, even if it's nearly finished, so installation timing relative to that date genuinely matters. Confirm current filing requirements with your specific municipality rather than assuming the exemption applies without any action on your part.
High electricity rates are doing the heavy lifting
Central Maine Power customers pay around 27 cents per kWh, and Versant Power customers pay closer to 32 cents per kWh, both well above the national average. That high baseline rate, combined with full retail NEB credits, is the primary reason solar can still pencil out favorably in Maine even without a federal credit for cash or loan purchasers in 2026. Compare against the New Hampshire incentive estimator for a neighboring state's different structure.
Your rebate total changes what a loan costs each month, and the combined loan and rebate timing tool shows that payment once you enter both figures.