Solar panel kits

Click here to see our selection of Solar panel kits.

When shopping for solar panel kits, check out the different ratings. It is important to know just how a kit will perform before purchasing it. However, before checking out the different ratings of different kits, it is important to first know the difference between Standard Test Conditions (STC) and PVUSA Test Conditions (PV).

For most solar panel kits, the STC rating will be higher than the PV rating. The STC is a watt-rating used by manufacturers, while a PTC rating is based on a 1000 watt/m² solar irradiance, 20 degree Celsius ambient temperature above ground level, and 1 meter/second wind speed. The PV USA test conditions are much more realistic than the Standard Test Conditions, therefore it is more important to buy solar panel kits that have a high PTC rating, rather than an STC rating.

The STC is at 25 degrees Celsius for the cell temperature, but a silicon solar cell is much more likely to average 20 degrees C above ambient temperature, just as the PV USA test conditions dictate.

When shopping for solar panel kits, compare the PTC and STC ratings.

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