Trust
Where the numbers come from
No number on this site originates from another solar website. These are the primary datasets we build on, what each one feeds, and how often it updates.
| Source | What it feeds | Update cadence |
|---|---|---|
| U.S. Energy Information Administration (EIA) | Residential electricity rates, consumption, and utility data | Monthly (Electric Power Monthly) and annual (Form EIA-861) |
| NREL PVWatts | Solar production estimates by location, tilt, and system size | Model v8, updated by NREL |
| LBNL Tracking the Sun | Installed price per watt for residential systems, by state | Annual |
| IRS and federal statute | Federal tax credit status, including the end of Section 25D | As law changes |
| State agencies and utility program pages | State incentives, net metering rules, and battery programs | Re-verified on a schedule, date shown per page |
| State license boards | Installer license status and disciplinary records | Checked at grading and re-checked on update cycles |
| U.S. Census Bureau (ACS) | Household counts, housing stock, and income context by geography | Annual |
Where a page uses a source not listed here, the page cites it inline. If a number has no source link, treat that as our error and report it.