About

Solar Payback Calculator is a free utility built by Andrew Flores under Nathan Management, based in Baldwin Park, California. The site exists because we got tired of solar calculators that still applied the 30% federal Residential Clean Energy Credit after it expired on December 31, 2025. Most of the established calculators have not yet caught up, and the difference between the pre-2026 and post-2026 economics is substantial enough that running the wrong numbers can lead to a bad purchase decision.

What we use

Production estimates come from the National Renewable Energy Laboratory's PVWatts v8 model, which runs hourly typical-meteorological-year data through a system performance model based on inputs you provide. Electricity rates come from the U.S. Energy Information Administration's monthly Electric Power survey. State-level incentive information comes from DSIRE (Database of State Incentives for Renewables & Efficiency), maintained by NC Clean Energy Technology Center, and from each state's utility commission filings.

What we do not do

We do not collect leads. We do not forward your information to installers. We do not run a sponsored-quote engine behind a calculator interface. The numbers you enter never leave your browser unless you explicitly contact us through the contact page. The site is supported by display advertising, kept to a maximum of two ad units per page, below the fold.

Who runs this

Andrew Flores, Baldwin Park, California. Reach us through the contact page. Errors in state data, broken calculations, and outdated incentive information are the kinds of things we want to hear about and will fix on the next data refresh.