Three ways to check a number on this site without taking our word for it.
1. Click through to the source
Every computed page ends with a "How this page was computed" block naming the exact formula and linking every external number to where it came from — a NOAA station ID, a PVWatts request, a manufacturer datasheet URL with the date it was checked.
2. Re-run it yourself
The /methodology/ page lists every constant this engine uses. The formulas themselves — cold , wire ampacity, battery bank sizing, the hour-by-hour simulation — are standard textbook and code-reference material (NEC 690.7/690.8, ABYC E-11): nothing here is a proprietary black box, so the same inputs plugged into those standards should reproduce the same output.
3. Compare the live checker against a page
Every reference page — a panel card, a station page, a kit audit — links to the same build already loaded in the checker. Open it, change the location or month, and the numbers update from the identical engine that rendered the static page, not a second copy that could drift out of sync.
These results are for reference. Wiring must be installed by a qualified electrician. Mobile installations follow ABYC E-11; stationary ones NEC 690/706.