When choosing photovoltaic modules it is essential to pay attention to the technical characteristics that have the biggest impact on the operation of the solar power plant and energy yield. These characteristics are:

• Power output tolerance - the information tells us what the potential power discrepancies among the modules are. Lower the tolerance, smaller the discrepancy is.
• Nominal operating cell temperature (NOCT) – for how many degrees Celsius the cells in the module warm up during operation. Lower this factor is, greater the energy yield at high irradiation is.
• Power temperature coefficient – this information tells us for how many percentage changes module efficiency according to the change of 1° C. Lower this characteristic is, smaller efficiency degradation in the increase of temperature is.
• Allowed mechanical loads - information about the rigidity of photovoltaic module. Higher the mechanical loads are more is the module resistant to the weather conditions (mainly snow).
• Warranties on power output and product and IEC 61215, IEC 61730 certificates.

All technical characteristics that you compare must be obtained at standard test conditions (AM1.5 air mass, irradiation 1000W/m² and ambient temperature of 25° C).