Solar Panels & Temperature 2

Despite popular belief, the power output of a solar panel decreases with the increase of the panels temperature. The listed power of a solar cell is the power measured under ideal laboratory conditions, which prescribes a temperature of 25 °C. However, on a typical hot summers day, it is not uncommon for a solar cell to reach a temperature of 75 °C. The efficiency of some cheap solar cells can decrease more than 0.5% for every 1 °C above 25 °C. This means that on a hot summers day, the efficiency of a solar cell could drop as much as 25%. It is therefore extremely important to keep your solar panels well ventilated. Make sure the wind is able to cool on all sides, including the underside of the solar panel.

The Temperature Coefficient (Pmax)
The temperature coefficient is a characteristic of solar panels that can differ greatly, especially between cheap panels and quality panels. This characteristic however, should not be overlooked. For example on a hot summers day the temperature of your solar panels may be around 75°C, this will equate to a power loss according to the solar panels temperature coefficient.

With Sanyo Hybrid panels from Gold Coast Solar Power Solutions the temperature coefficient is -0.30% per °C above 25°C. This would equate to a loss of 157W at 75°C just from heat on a 1.05kW solar power system.
However with some cheaper panels offered by other companies the temperature coefficient can be greater than -0.52% per °C above 25°C. This equates to a loss of 273W at 75°C on a 1.05kW solar power system!

So with this cheaper, so called “cost effective” panel this loss alone equates to 116W of a 1.05kW system that you have paid for which is lost compared to the higher quality Sanyo panel on a good summers day! Imagine the extra power loss on a larger system! That is more than a 10% loss in output over a higher quality solar panel, add to that the piece of mind that comes with purchasing from a reputable brand and knowing that they will be around in the years to come to honour their product warranties.. suddenly the quality solar panels look a lot more appealing.
Source : http://gcsolar.com.au/solar_power/solar-panels-temperature/