Each solar cell technology comes with a unique temperature coefficient. This temperature coefficient is important as the temperature of the solar cell has direct influence on the power output of a solar module.
As the temperature in which a solar module operates increases, the power output of the solar module will decrease.
Crystalline solar cells are the main cell technology and usually come with a temperature coefficient of around -0.5% / Degrees Celsius.
The rated power on the module’s label is measured at 25 degrees Celsius, and with any temperature increase above °C 25 you have to take
into account a power loss of 1% for every °C2 increase.
Most installed solar modules in sunny countries easily reach temperatures higher than °C25. In fact a temperature of °C50 can be easily reached.
Here’s a screenshot from Trina Solar ALL-Max solar module:
Let’s take Trina Solar’s solar module as an example, and calculate the power loss when these solar modules are installed in a hot country:
We pick their currently highest power poly 60Cell : the 260W.
Let’s have a look at an example if the solar cells inside a solar module reach °C65:
With the solar module reaching °C65, the power loss of this module is:
°C65 – °C25 = °C40
°C40 x -0.41% = -16.4%
Solar module power loss: -16.4% x 260W = 42.64W
The max. power this module will operate is 217W. Good to know when you're calculating the ROI of your PV plant!