How this Lewiston estimate works
- Annual production = system size × 1,311 kWh/kW planning yield.
- Retail-value ceiling = annual production × current Maine residential electricity price.
- The value-capture control lets you haircut that ceiling for self-consumption/export economics.
- Simple payback = entered net installed cost ÷ modeled annual electricity value.
Source boundaries
1,311 kWh/kW-year modeled at Lewiston in the 2026 Solar Pool & Roof state comparison using NREL PVWatts v8; planning benchmark, not a roof-specific forecast. Roof orientation, shading, equipment, weather year and utility export compensation can materially change the result.
What is localized in Lewiston
Lewiston currently uses the Maine state/regional planning fallback for production and installed cost, so the displayed city and state benchmark values are the same. This page does not claim city-specific roof economics.
Production basis: PVWatts-based state planning benchmark · electricity benchmark: EIA 2026-07.
Lewiston solar methodology
Production precision: state/regional benchmark disclosed for Lewiston; no unverified city-specific production uplift is applied.
Production basis
1,311 kWh/kW-year planning benchmark. This page explicitly uses the state/regional fallback rather than claiming site-specific city precision.
Installed-cost basis
2.93 $/W planning benchmark for this city/region; not an installer quote.
Electricity benchmark
32.41¢/kWh Maine residential benchmark for 2026-07.
Utility boundary
The city page does not assume one electric utility. Use an available city × utility page when the service territory is verified.
- PVWatts-based state planning benchmark · production benchmark
- State/regional installed-cost benchmark · Sep 2026 · cost benchmark
- EIA Electric Power Monthly Table 5.6.A · 2026-07 · state residential rate
Methodology: Solar utility model · CalcuRiver methodology.
Related Lewiston and Maine calculators
Why this solar estimate changes
Solar value is driven by local production, installed cost, the retail value of electricity you avoid buying, and the compensation you receive for exported energy. CalcuRiver does not assume export credits equal the retail rate unless that utility program is explicitly verified.
Core logic: self-used solar offsets retail purchases; exported solar is valued only under a verified export-compensation rule.
Methodology & source policy