About RoofPayback

Most solar calculators ask for your phone number before they show a single number, and the payback figures you find online range from "5 years" to "never" depending on who is selling.RoofPayback shows the math in the open: the data, the assumptions and the model, and you can change all of them.

Principles

• Verifiable data: production from the U.S. Department of Energy's PVWatts, prices from the U.S. EIA — not from sales brochures.
• No lead capture: the calculator runs in your browser. We don't collect your address or sell contacts to installers.
• Independence: the site is funded by clearly labeled advertising. Advertisers never review or change the calculations.
• Public corrections: if something is wrong, we fix it and say so. Read the methodology.

Who runs it

RoofPayback is an independent project published by Eric. Reach us through the contact page.