High Ambient Temperature Solar Panel Efficiency

Photovoltaic modules are tested at a temperature of 25 degrees c stc about 77 degrees f and depending on their installed location heat can reduce output efficiency by 10 25.

High ambient temperature solar panel efficiency. If a panel with a temperature coefficient of 0 4 c were to reach an extreme heat of 65 c it would reduce output by as much as 26 0 4 x 65. It may seem counter intuitive but solar panel efficiency is affected negatively by temperature increases. Panels can get very hot. Home solar panels are tested at 25 c 77 f and thus solar panel temperature will generally range between 15 c and 35 c during which solar cells will produce at maximum efficiency.

The effect of high temperatures. The actual value of the temperature coefficient in particular depends not only on the pv material but on t ref as well. It is given by the ratio 1 ref oref tt 4 in which t o is the high temperature at garg and agarwal 19. If these solar panels heat up to 45 c 113 f that means they are 20 c above the stc temperature.

The temperature coefficient tells us the rate of how much will solar panel efficiency drop when the temperature will rise by one degree celsius 33 8 f. Higher temperatures will cause the efficiency to drop whereas colder temperatures will cause the efficiency to increase. Rising cell temperature reduces power output by a specific amount for every degree above 25 c. There are other variables that influence your solar panels efficiency rating including their temperature.

For crystalline silicon solar cells this temperature is 270 o c evans and florschuetz 20. In many instances a solar cell can get as hot as 65 c causing the panel to become less efficient and therefore produce less power. The energy production efficiency of solar panels drops when the panel reaches hot temperatures. For example when the temperature coefficient is minus 0 5 percent it means that efficiency decreases by 0 5 percent for every degree above 25 c or every 33 8 degrees above 77 f.

Generally cell temperature is 20 30 c higher than ambient air temperature which equates to approximately 8 12 reduction in total power output depending on the type of solar cell and its temperature coefficient. However solar panels can get as hot as 65 c 149 f at which point solar cell efficiency will be hindered. As the temperature of the solar panel increases its output current increases exponentially while the voltage output is reduced linearly. Most premium efficiency solar cells are made of monocrystalline silicon.

The article also added that the soaring temperatures to as high as 50 c 122 f and the accumulation of dust due to winds are resulting in the drop of efficiency of the solar panel by as low as 40 percent.