The inherent property of silicon generally means the higher the temperature, the lower the efficiency. With monocrystalline PERC cells having a temperature coefficient of -0.4% -0.5%/ ℃, N-type TOPCon cells and modules differentiate themselves by having one below -0.3 %/ ℃. This means that, whereas a PERC panel loses half of one percent of its power with each degree of temperature increase, an N-type TOPCon panel will lose only 0.3% or less.
Taking JinkoSolar’s new Tiger Neo 610W (STC) module as an example, it has a better than average power loss of only -0.3% / ℃ compared with the PERC equivalent of -0.4%/ ℃. Assuming maximum output power of 610W in a module installed in desert conditions with temperatures reaching 50 degrees Celsius, power loss can be calculated as follows:
50 degrees C – 25 degrees C = 25 degrees C.
Therefore, panel power loss difference = 25 ° C x (0.4%-0.3%) x 610 W = 15.25W.
In conclusion, the temperature coefficient is a parameter used to calculate power loss, usually ranging between -0.3% and 0.5% / ° C, meaning that a temperature increase of 10° C will result in a module power drop of between 3% and 5%. This formula clearly indicates that TOPCon technology, with a 0.3%/°C coefficient, will limit any such power drop to less than 1/3 of the power loss of a PERC module.
This is an important factor for investors in PV power plants, since it significantly affects profitability, making TOPCon modules a preferred choice for large installations and, in the case of ultra large installations operating at high temperatures, a necessary choice.