A calculator for off-grid solar systems — vans, cabins, backup power — built from manufacturer datasheets and NREL/NOAA weather data instead of rules of thumb. 290 verified components, 318 locations, 40 kits already audited against every wiring rule.
Start from what you have
- How much solar do you need, by location 318 locations
- Parts catalog 290 components
- Solar kits, audited manufacturer kits checked against every rule
- Portable power stations which panels are safe to connect, by temperature
- Guides 12 long-form explainers, each with a live calculator
Why the numbers here differ from a marketing page
A panel's open-circuit voltage is higher in the cold than the 25 °C label figure — enough, in some string/controller combinations, to damage the controller on the first hard frost. A battery's BMS can trip an inverter that the battery's own Ah rating suggests it should carry. Every page here runs the actual formula (NEC 690.7, ABYC E-11) at the actual location's design low, not the label number. See how.
These results are for reference. Wiring must be installed by a qualified electrician. Mobile installations follow ABYC E-11; stationary ones NEC 690/706.