Sun data

Solar by location and season

January in Michigan isn’t July in Arizona. Enter a ZIP and your panel watts to see what each month really gives you, from five years of measured sun.

Updates as you typeNew on Megawatt RV

Where you camp

Real sun data
400 W
2,500 Wh

Not sure? The battery bank calculator adds up a typical day for your rig.

Watt-hours per day, by month

No place yet
How the math works

Open-Meteo’s historical weather API reports daily shortwave radiation on a flat surface in megajoules per square meter. Divided by 3.6, that’s kilowatt-hours per square meter, which is the same number as peak sun hours. This tool averages five full years by month, then multiplies sun hours × panel watts × 0.75, the efficiency the original Megawatt calculators use.

Flat is how most RV panels sit, so no tilt correction is applied. Shade from trees and canyon walls isn’t in the data.

Keep planning

Solar plannerRoof layout, three build tiers, parts listsBattery bankDaily loads, days off-grid, and solar in. Voltage, amp-hours, and the Vatrer battery out.Solar arrayWatt-hours and sun hours in. Minimum array and pack counts out.Battery runtimeBattery size, usable share, and load in. Hours and a discharge curve out.