Editorial policy

How this site is produced

PlainSolarData is a data reference compiled from public datasets. Every figure, irradiance, electricity rate, system cost, payback, the Solar Score, incentive counts, is computed directly from the source records rather than entered by hand, and page text is drawn from that same source data using fixed templates. We do not claim that each page is individually written or reviewed by an editor; the value here is accurate figures traceable to their source.

According to the U.S. Energy Information Administration, total U.S. installed solar capacity reached 124,310 MW in December 2024; the National Renewable Energy Laboratory reports average irradiance of 3.4 to 6.5 kWh/m²/day across the states, and the DSIRE registry tracks 137 incentive programs. These are the sources behind every figure on the site, see our methodology for how each is computed.

Where the data comes from

• NREL - National Solar Radiation Database (irradiance) and Annual Technology Baseline (installed-cost benchmarks).
• U.S. EIA - residential electricity rates and installed solar capacity by state and year.
• DSIRE - the Database of State Incentives for Renewables & Efficiency (programs and net-metering classifications), maintained by the N.C. Clean Energy Technology Center.
• U.S. DOE - federal solar program references.

The exact formula for the Solar Score and the payback model is documented on our methodology page.

Independence

We do not accept payment from solar installers, equipment manufacturers, utilities, or financing providers in exchange for coverage, placement, or rankings. Rankings and scores are computed from the data; they cannot be bought. The site carries third-party display advertising (clearly labelled), which is independent of the rankings and editorial content.

Estimates and limits

Payback periods, annual savings, and the Solar Score are modeled estimates from state-average inputs. They are comparison aids, not guarantees or financial advice. Real results depend on your roof, shading, utility tariff, system size, and installer pricing. Federal and state incentive rules change; we note major changes but you should confirm current rules with the issuing agency and a tax professional before acting.

Corrections

If a number looks wrong, tell us, see our corrections process. We trace reported errors to the source record and fix them at the data layer so the fix propagates everywhere the value appears.