Solar Panel Temperature Coefficient: What To Know

last updated at September 20, 2023

A solar panel temperature coefficient plays a big part in your system's efficiency

A solar panel's temperature coefficient plays a big part in your system's efficiency. It describes how much a panel's power output drops for every degree Celsius above 25°C (its rated test temperature).

Most crystalline silicon panels have a coefficient between -0.3% and -0.5% per °C, meaning output can drop noticeably on hot summer afternoons even with full sun.

Proper mounting with airflow underneath the array, and choosing panels with a lower (better) temperature coefficient, both help preserve production during peak heat.