The colder a solar panel gets the more efficient it seems to be. As the panel warms, it loses some efficiency. Why is this so? Please explain in a way you would expect a high school kid to understand it, as I am a high-schooler and i have to explain this to other high-schoolers.
Absolutely temperature matters. So what do higher temperatures do to solar photovoltaic panels? As temperatures rise, the efficiency of solar panels decreases. Heat causes electrical resistance to the flow of electrons. On days where the temperature is more than 75 degrees, the electrical resistance makes the voltage fall thereby producing less kilowatts per hour. Your roof is much hotter than temperatures on the ground. That’s why solar panels are not mounted flat to a roof. There’s usually a few inches of spaces between the panels and roof so air flow can easily pass through and cool the panels down. There are some photovoltaic panels that are designed specifically to operate in hotter temperatures. These panels have a higher temperature coefficient. This is especially important in high heat climates like Arizona or New Mexico, but probably wouldn’t make too much of a difference in New England (except maybe this year). If someone lives in one of these areas, they should speak to a solar installer to make sure they are using they right equipment for their region. Please note: Solar thermal panels used to heat water can withstand high temperatures without any degradation. In fact, hotter temperatures would actually be better for these types of modules.
For water heater type of solar panel the hot panel has more radiation losses reducing the heat available to be transferred to the water. In PV panels it has got to be characteristics of the PV cells. If the conversion efficiency drops with temperature rise then only this can happen. PV=photo-voltaic
All PV Solar Panels are affected by heat. The hotter the solar panel, the lower the power output - but how significant is the effect. I decided to test one of our small 6V 250mA Solar Panels to find out. Solar Panel next to halogen lamp with temperature probe. Reproducing the kind of temperatures solar panels experience in hot climates is not easy on a cloudy May day in the UK, so a 50 Watt halogen office lamp was used at a distance of 55mm from the solar panel as a sun substitute. This guaranteed a constant level of light would be incident upon the solar panel ensuring the quality of the results collected.
