What is the temperature coefficient of a solar module?

Each solar cell technology comes with a unique temperature coefficient. This temperature coefficient is important as the temperature of the solar cell has a 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:

 Temperature coefficient solar panel - Trina Solar[/caption] 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!