Maine Solar Calculator

Enter your utility and monthly bill — get system size, Net Energy Billing savings, federal ITC, property tax exemption, and 25-year projections. Maine's $0.22/kWh rates make solar highly competitive despite 4.0 PSH.

Your Maine solar inputs

Monthly electric bill?

Electric utility?

Community solar (no rooftop needed)?

System size?

Maine solar estimate

20 × 400W panels (8 kW system)

Recommended size for your bill: 8.6 kW

Monthly usage818 kWh/mo

Annual production (ME 4.0 PSH)9,344 kWh/yr

Annual savings (NEB at retail)$2,056/yr

Gross system cost$24,800

Federal ITC (30%)-$7,440

State income tax creditNone

Net cost after ITC$17,360

Property tax exempt (est.)$5,406

Payback period8.4 yrs

25-year savings$51,392

Maine's Net Energy Billing (NEB) credits exported solar at retail rate. Maine's high rates ($0.22/kWh) make each kWh of solar worth significantly more than in most states — delivering strong ROI despite 4.0 PSH.

Link copied to clipboard

How to Use This Calculator

Maine's high rates are the key insight

Maine residents pay some of the highest electricity rates in the United States — CMP (Central Maine Power) charges approximately $0.22/kWh, while Versant Power charges approximately $0.20/kWh. For comparison, the US average is $0.17/kWh. This means each kilowatt-hour of solar saves 30-40% more in Maine than in an average US state. This single factor largely compensates for Maine's lower solar irradiance (4.0 PSH versus the US average of 4.3). Maine solar works because of expensive electricity, not despite lower sun.

Net Energy Billing (NEB) at retail rates

Maine's Net Energy Billing program is Maine's version of net metering. Exported solar earns credits at your full retail rate — $0.22/kWh for CMP customers, $0.20/kWh for Versant customers. These credits accumulate month-to-month. Any excess annual credits are settled at a lower rate, so sizing your system to your annual consumption (not exceeding it) maximizes your credit value. Maine's NEB is one of the strongest solar billing policies in New England.

Community solar — no roof required

Maine has a robust community solar program. If you rent, have significant roof shading, have a structurally limited roof, or simply prefer not to own panels, community solar lets you subscribe to a share of a local solar farm. You receive bill credits (typically 10-15% off your bill) without installation, ownership, or maintenance. Toggle the "Community solar" option to see estimated savings without rooftop solar.

The Formula

Monthly kWh = Monthly Bill ÷ Electricity Rate Annual Production = System kW × 1000 × 4.0 PSH × 365 × 0.80 efficiency ÷ 1000 Annual Savings = Annual Production × Retail Rate (NEB at retail) Gross Cost = System kW × 1000 × $3.10/W ITC Credit = Gross Cost × 30% Net Cost = Gross Cost − ITC Credit Payback = Net Cost ÷ Annual Savings Community Solar Annual Savings = Annual kWh × Rate × 10% discount

Maine uses 4.0 peak sun hours — Portland gets 4.1 PSH, Bangor gets 3.9 PSH, northern Maine gets 3.7-4.0 PSH. The $3.10/W installed cost reflects Maine's higher installation costs (smaller market, shorter installation season, higher labor costs). Maine's high retail electricity rate — the most important variable — means each kWh of solar production saves significantly more than in lower-rate states.

Example

Karen — Portland CMP customer

Karen pays $180/month to CMP at $0.22/kWh. She wants an 8 kW system for her Portland home.

Monthly bill$180 (CMP, $0.22/kWh)

System8 kW, south-facing

LocationPortland, ME (4.1 PSH)

Result

Annual production~9,344 kWh/yr

Annual savings (NEB at $0.22)~$2,056/yr

Gross system cost~$24,800

Federal ITC (30%)-$7,440

Net cost after ITC~$17,360

Payback period~8.4 years

25-year savings~$51,400

Maine's $0.22/kWh rate transforms the economics: Karen's 8 kW system saves over $2,000/year despite Maine's relatively modest 4.0 PSH. An identical 8 kW system in Idaho (4.7 PSH but $0.10/kWh) would save only ~$1,100/year. Maine's payback period of 8.4 years is competitive with Sun Belt states — proving that high electricity rates matter as much as sunshine.

FAQ

Why are Maine electricity rates so high? ▼

Maine's high electricity rates reflect several factors: (1) Grid infrastructure costs spread across a low-density, rural population; (2) Cold climate requiring robust grid design for extreme winter conditions; (3) Fuel mix with limited local generation and dependence on natural gas and oil from other regions; (4) Transmission costs for moving power across long distances in a small state with limited generation; (5) CMP's ongoing infrastructure investments. Maine rates have been rising 8-12% annually in recent years. This rate trend makes solar increasingly valuable each year you wait — and makes today's solar investment more compelling.

What is Maine's Net Energy Billing (NEB) program? ▼

Maine's Net Energy Billing (NEB) is the state's solar export policy. When your solar system produces more electricity than you use at any given moment, the excess flows to the grid and earns a credit at your full retail rate ($0.22/kWh for CMP). These credits appear on your monthly bill and roll forward month to month. On your May 1 annual settlement date, any remaining credits are paid at a lower "avoided cost" rate. To avoid this lower-rate settlement, size your system to produce no more than your annual consumption. NEB is governed by Maine PUC rules and applies to CMP and Versant residential customers with systems up to 660 kW.

How does Maine community solar work? ▼

Maine's community solar program (authorized under LD 1711) allows residents to subscribe to a share of a community solar project — typically a ground-mounted solar farm in their utility territory. Subscribers receive bill credits equal to their share of production, typically offered at 10-15% below retail rate (meaning you pay slightly less than retail for your community solar credits). Benefits: no rooftop installation needed; available to renters; no maintenance; no ownership responsibility. Waitlists exist for some projects. Search "Maine community solar" or check Maine PUC's list of approved community solar projects for current availability.

Does Maine have a property tax exemption for solar? ▼

Yes — Maine exempts solar energy equipment from property taxes. Under Maine's property tax exemption, the added value that a solar system contributes to your home is not included in your property's assessed value for tax purposes. Maine's average property tax rate is approximately 1.09% of assessed value. For a $24,800 system, this exemption saves approximately $270 per year — or about $5,400 over 20 years. This is a meaningful but secondary benefit compared to Maine's primary advantage: high electricity rates making solar very high-value.

Is solar worth it in Maine despite lower sunshine? ▼

Yes — Maine's solar economics are stronger than most people realize. The key insight: Maine's electricity rate of $0.22/kWh is more than twice Idaho's $0.10/kWh. An 8 kW system in Maine (4.0 PSH) produces fewer kWh than in Idaho (4.7 PSH), but each Maine kWh is worth 2.2x more. The net result: Maine solar saves about $2,000/year versus ~$1,100/year in Idaho — despite Maine having 15% less sunshine. Add retail-rate NEB, property tax exemption, and the 30% federal ITC, and Maine solar achieves payback periods competitive with states that get far more sun.

Related Calculators

Embed This Calculator

Free to embed on your website. Just copy this code:

<iframe src="https://solarsizecalculator.com/us/solar-calculator-maine"
  width="100%" height="700" frameborder="0"
  title="Maine Solar Calculator"></iframe>