The temperature dependence of a material is described with a temperature coefficient. For polycrystalline PV panels, if the temperature decreases by one degree Celsius, the voltage increases by 0. The temperature coefficient of a PV cell is basically a measurement how much the output power of the cell decreases as its ambient temperature rises above a standard 25 o C. You'll learn how to predict the power output of a PV panel at different temperatures and examine some real-world engineering applications used to control the temperature of PV panels. For example, if a solar panel has an efficiency rating of 20%, it means that 20% of the sunlight hitting the panel is converted into electrical energy, while the rest is reflected or lost as. Temperature Coefficient is Critical for Hot Climates: Solar panels with temperature coefficients of -0. 30%/°C or better (like SunPower Maxeon 3 at -0. 27%/°C) can significantly outperform standard panels in consistently hot climates, potentially saving thousands in lost energy production over the.