SR SolarRoost

Methodology

SolarRoost Method v1.0, published October 4, 2026.

Cost basis

Planning examples price systems at the National Renewable Energy Laboratory residential benchmark of about $3.25 per watt DC for 2024, from NREL's U.S. Solar Photovoltaic System and Energy Storage Cost Benchmarks series (checked October 4, 2026). It is a national modeled benchmark, used as a comparison line for quotes. It is not a quote, a price cap, or a claim about your installer.

Production

Metro pages use planning production factors (kWh per kW per year) consistent with NREL PVWatts modelling for each area. A factor is a planning example. Your roof needs its own PVWatts run with its tilt, azimuth, and shading, and any installer estimate should name the tool and assumptions behind it.

Electricity prices and savings

Metro examples use a stated example electricity price, rounded from U.S. Energy Information Administration residential price data (checked October 4, 2026), and a stated $180 example monthly bill. Savings assume production first offsets usage at that price. Where export compensation is below retail, real savings are lower; the estimator lets you use your own price, and the net metering guide explains the effect.

Incentives

No federal residential solar tax credit is assumed anywhere on this site; it ended for systems placed in service after 2025. State, local, and utility incentives are verified through DSIRE and utility tariffs, and pages point there instead of printing program values that can go stale. The estimator only counts incentives you enter as confirmed.

Review process

Pages pass source verification (figure to named source and date), formula test (payback arithmetic checked against hand-worked examples), and editorial review (estimates labelled, no installer rankings, no lead forms). Dates distinguish review, source verification, and figure changes; cosmetic edits do not move a date.

Limits