What is solar capacity factor?

The capacity factor is a key metric used to evaluate how efficiently a power generation system operates.

It represents the ratio of actual electricity generated over a period of time compared to the maximum possible output if the system operated at full capacity continuously. For solar PV systems, this is typically measured over one year (8,760 hours).

A higher capacity factor indicates better energy production efficiency, while a lower value suggests less effective utilization.

Capacity factors vary by location due to differences in sunlight availability and weather conditions. In general, regions with higher solar irradiance—such as southern Taiwan—tend to achieve higher capacity factors, while areas with frequent cloud cover or rainfall typically have lower values.