Photovoltaic panels can power your air conditioner and keep your home cool as the temperatures rise in the summer. In fact, your panel array functions best on days when the sun is shining brightly and no clouds are in the sky.
But while sunny summer days may seem ideal for harnessing energy from the sun, intense temperatures do affect your solar panel system.
High Temperatures Reduce Efficiency of Photovoltaic Panels
We know that temperature doesn’t alter how much solar energy photovoltaic panels take in. However, high temperatures can affect how much power is produced from that energy.
As the mercury rises, your solar panels produce less electricity from the same amount of sunlight. Here’s why:
Heat changes the speed at which the electrons in a solar cell travel, which affects the flow of electricity. According to one experiment conducted in the United Kingdom, solar panel power output begins to drop when the temperature reaches 42 degrees Celsius, or roughly 107 degrees Fahrenheit. And for each degree Celsius the mercury rises above this, panel efficiency decreases 1.1 percent.
Given that solar panels can be up to 20 degrees hotter than the ambient air temperature, this means that solar output may start declining when summer temps hit 87 degrees Fahrenheit.
Determining the Efficiency of Your Photovoltaic Panels
The effect of heat on solar panels can be estimated through the use of complicated scientific equations. But you don’t have to do any math. Just take a look at the specifications for your photovoltaic modules to see how well they will tolerate the intense summer sun.
Solar panels are laboratory tested at a standard temperature of 25 degrees Celsius (77 degrees Fahrenheit). On your spec sheet, look for the temperature coefficient Pmax. This figure tells you how much power the panel will lose when its temperature rises above the standard test condition temperature.
Tips to Reduce the Effects of Heat on Your Photovoltaic Panels
If you live in a climate with hot summers, you can take steps to minimize the effect of high temperatures on your solar panels.
Choosing panels that are constructed with lighter materials can help, as darker colors absorb more heat. Locating your inverters behind the array so that they are shaded from the sun helps as well.
Finally, it’s advisable to install your solar panels a few inches above the roof. This will provide airflow all around the modules, which can help keep them cooler.
The experts at Intermountain Wind & Solar understand how to design your system to maximize your output of free solar power. Based in Utah, we provide photovoltaic systems for commercial and residential applications throughout the Intermountain West. Contact us today to request a complimentary estimate for adding photovoltaic panels to your home or business.