Solar Panel Output Calculator- Estimate the Real Energy You Can Get From Your Solar Panels

This solar panel output calculator helps you estimate the real daily energy, a.k.a. solar power as a function of time, in kWh or Wh, that your solar panel can produce, taking into account its rated power and solar energy available at your place.

This calculator may come in handy when you buy solar panel(s) for your RV vehicle, boat, camper or home solar system, and you want to get a real estimate for the production capability of your solar panel(s).

Warning: this calculator only takes into account only solar panel losses due to temperature, dirt, etc. It does NOT take into account, for example, any losses introduced by the rest part of your solar panel system.

Below you can find some typical losses your solar system might incur due to the components as follows:

  • Charge controller losses: 20% for PWM charge controllers( average efficiency 80%), 8% for MPPT charge controllers (average efficiency 92%)
  • Total cable losses = 3-5%
  • Battery losses = 20%
  •  Inverter losses = 8%

If you are looking for a calculator taking into account the above losses, you can use our free  Off-grid solar power  system calculator

Other useful solar power calculators and tools:

How to use Solar Panel Output Calculator?

Actually, you have at your disposal two solar calculators:

–      For the Forward task: estimate expected solar panel energy daily energy output in KWh (or Wh) based on your solar panel(s).

–      For the Reverse task: estimate the rated power of solar panel(s) taking into account your expected daily energy needs in KWh (or Wh)

An useful reminder: 1kW = 1,000W and 1kWh = 1,000 Wh

For the Forward task: Just enter the solar rated power and average peak sun hours (PSH) at your location, then click on the “Update” button to get the daily energy your solar panel(s) can produce.

For the Reverse task: Just enter your presupposed daily consumption, average peak sun hours (PSH) at your location, then click on the “Update” button to get the rated solar power you need.

How to find peak sun hours (PSH) at your location?

Here is how you can find the daily value of the Peak Sun Hours (PSH) for your location, depending in which part of the world you reside:

1) For the USA – click on the following link ,

then expand the “Solar Resources” folder on the left, and tick the “Avg. Annual Tilt at Lat” checkbox. You are going to see a map of the USA containing plots of the PSH. If you click on the little black arrow next to the checkbox, you can expand the legend and see the PSH value for your location after properly zooming the map to find your location.

2) For Europe – click on the following link

Warning: If you have the total of global irradiation in kWh/m2 for a given location, you have to divide such value by 365 to get the daily value of PSH

3) For Australia and New Zealand – click on the following link:

4) For areas outside the USA, Europe, and Australia/New Zealand – find the PSH daily value for your country from the World map of direct normal irradiance. “Normal irradiance” means that those values are valid for solar panel positioned perpendicularly to the sunbeams. Therefore, the tilt of your solar panel is equal to the latitude of your location.

You may also like:

How to use solar panels of different wattage in your solar power system

The most commonly used solar panels 

The definitive guide to solar batteries

The following two tabs change content below.
Lacho Pop, MSE, holds a Master's Degree in Electronics and Automatics. He has more than 15 years of experience in the design and implementation of various sophisticated electronic, solar power, and telecommunication systems.  He authored and co-authored several practical solar books in the field of solar power and solar photovoltaics. All the books were well-received by the public. You can discover more about his bestselling solar books on Amazon on his profile page here: Lacho Pop, MSE Profile