• Benadette Wambui

Solar Energy Calculations

How to calculate solar panel output is a common question. It makes sense, considering the impact solar panel production has on the overall system. Exactly how to calculate the power output of your solar panels involves a few variables and steps.


Some of the most important factors in figuring out your solar panel output include:

  1. Your solar panels’ efficiency.

  2. How much sunlight shines on your solar panels(location).

  3. Which direction your solar panels are facing

The three above are the main contributors but there are other factors that change the final output. We will go over each of these as well as give a formula for exactly how to calculate solar panel output.


Solar Panel Efficiency


While wattage can tell you what your solar panel is capable of producing under ideal conditions, efficiency tells you how much sunlight your solar panel is capable of converting into electricity you can use in your home. For example, if your solar panel has an efficiency rating of 13 percent, that means that 13 percent of the sunlight striking your solar panel will be transformed into the power you need to toast bread or do a load of laundry.Solar panel efficiency can be affected by a few variables itself, which can either subdue or boost it. Within the solar cells themselves, there can be variation in efficiency based on how reflective the cells are. Less reflective cells can collect more sunlight and use it rather than bouncing it back out to space. The area around your rooftop solar panel system can also change your efficiency numbers. The most common environmental factors that can subdue efficiency are:


  • Shading from nearby trees or other buildings.

  • Excessive cloud coverage