Megawatt RV
Plan my solar

Calculators / Sun by location

Sun by location

How much sun will I get there?

Type a ZIP or a town. See what your panels made month by month last year, and what the next seven days look like.

How the math works
  • Month by month uses the Open-Meteo Historical Weather API: daily shortwave radiation for last calendar year, averaged per month.
  • Shortwave radiation comes in megajoules per square meter. Divide by 3.6 and you get kilowatt-hours per square meter, which is the same thing as peak sun hours on a flat panel.
  • Daily output = panel watts × sun hours × 0.75, the same efficiency as the other Megawatt calculators.
  • The week view uses the Open-Meteo forecast. Battery charge is bookkeeping from the numbers you enter, not a shunt reading.
  • Panels flat on an RV roof see less than tilted house panels. That is already baked in, because the data is for a flat surface.

Added in this rebuild. Same 0.75 system efficiency as the original Megawatt solar and battery tools where it applies. This is a planning tool. Have a qualified electrician check anything you wire.

Try another tool

How many solar watts should go on the roof?

Daily use and sun hours in. Panel watts and pack counts out.

How much battery does my rig need?

Loads, nights, and solar in. A Vatrer bank size out.

When does solar pay for itself?

A breakeven chart from your own numbers.