Capacity factor solar
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
8760 × MW × 20%
About this calculator
The solar capacity factor calculator estimates annual energy production from a photovoltaic plant based on the capacity factor. This factor represents the ratio between actual yearly energy output and the maximum possible output if the system operated at 100% of its nominal power 24/7. For solar, typical values range between 15% and 25%, varying by location, climate, and technology.
The formula used is: Annual Energy = 8760 hours × Installed Power (MW) × Capacity factor (%). For example, a 1 MW system with 20% capacity factor produces 1,752 MWh/year. This tool is critical for economic feasibility studies, system sizing, or comparing solar farms in different regions.
Note that real-world capacity factors depend on local solar irradiance, panel orientation, shading losses, and maintenance. Higher values indicate better utilization of installed capacity, while lower ones reflect geographic or technical constraints.
Frequently asked questions
What is solar capacity factor?
It is the percentage of energy a solar plant actually generates versus its theoretical maximum based on installed power and 8,760 annual hours. A 20% capacity factor means the system operates at 20% of maximum capacity throughout the year.
How to calculate annual energy with this tool?
Enter the installed power in MW and the desired capacity factor. Multiply 8,760 hours × MW × (capacity factor/100) to get the result in MWh.
Why does solar capacity factor range from 15% to 25%?
This variation depends on local solar irradiance, panel orientation, technical losses, and weather conditions. Sunnier regions typically have higher capacity factors.
Can I use this for residential systems?
Yes, by adjusting the installed power (in kW) and using the typical 15-20% capacity factor for small-scale projects.