Solar panel efficiency decreases as temperatures rise above 25°C

High temperatures can negatively impact the efficiency and longevity of solar panels. While solar panels require sunlight, their power output begins to decline once cell temperatures rise above a reference point of 25 degrees Celsius.

Sandia National Laboratories, under the U.S. Department of Energy, models module temperatures by considering external air temperature, solar radiation intensity, wind speed, and mounting methods. This is critical because weather forecasts often do not reflect the actual heat experienced by a panel on a roof.

Different manufacturers show varying levels of temperature sensitivity. For example, the REC Group Alpha Pure-RX model experiences a power drop of 0.24 percent per degree Celsius, while the Qcells Q. TRON BLK M-G2+ series drops by 0.29 percent per degree Celsius. While models like the Qcells Q. TRON and REC Group Alpha Pure-RX can operate safely at temperatures up to 70 or 80 degrees Celsius respectively, the U.S. Department of Energy warns that extreme heat may cause permanent damage to cells and materials, shortening the product's lifespan.