Rooftop solar panels can get hot, particularly during scorching summer days. If the panels do get hot or overheat, they’ll produce less energy as the temperature rises above their optimal energy production range.
In general, residential solar panels are designed to reach their peak efficiency level at 77 °F (25 °C), but their efficiency will decrease by 0.5% for every degree above this temperature. The actual percentage of lower production varies by the solar panel’s manufacturer and model. Ultimately, you want to aim for an exterior temperature range of 59 to 95 °F (15 to 35 °C). Yet, it’s unrealistic for rooftop solar panels to stay within this range all year, especially in places where temperatures can go past 100 °F (37.8 °C). Fortunately, most solar panels can withstand heat up to 149 °F (65 °C).10
Nonetheless, solar panel overheating can be prevented. Many solar panel manufacturers cover the panels in a material that generally conducts and vents heat away from the glass. In addition, solar panels are usually mounted a few inches above the roof, which allows airflow space to help move heat away from the panels.
Despite the reduction in efficiency from extreme heat, solar energy generation doesn’t stop. The lower electricity production due to scorching weather balances out with the longer days of sunlight throughout the seasons. Although solar panels work best on cold, sunny days, they produce solar power year-round in nearly every location and climate.