For testing and reporting of performance values by an accredited laboratory, families of similar modules shall have the option to be grouped based on type. Multiple models may be included under a specific type, provided that the models are identical to the type, except for the STC power rating. Identical includes, but is not limited to, all structural components, materials, processes (including cell process), cell technology, encapsulation system, superstrate, backsheet/substrate, frame and/or mounting structure, junction box/electrical termination, cell interconnection materials and techniques, and internal electric circuitry.

For each type, the following tests shall be performed on the model with the highest STC power rating: Nominal Operating Cell Temperature (NOCT), temperature coefficient of short-circuit current, temperature coefficient of open-circuit voltage, temperature coefficient of maximum power current, temperature coefficient of maximum power voltage, and temperature coefficient of maximum power.

For each type, the models under that type shall be categorized into the smallest number of groups such that the STC power rating of the models within the group have a maximum range of ± 5 percent. For each of these groups, the model with the STC power rating closest to the average STC power rating of the models in the group shall be used for testing. If there are two models equally close to the average, the model with the highest STC power rating shall be selected. For each group, the following tests shall

be performed on the model with the STC power rating closest to the average STC power rating of the group: short-circuit current, open-circuit voltage, maximum power current, maximum power voltage, maximum power, maximum power and low irradiance current, maximum power and low irradiance voltage, current at NOCT, and voltage at NOCT.

Each model shall be associated with the two types (groups) that have reported test values, if scaling of performance characteristics is applicable. The factory measured maximum power of each production module, as specified in UL1703 standard, Section 44.1, and the lower bound of the manufacturer’s stated tolerance range, pursuant to UL 1703, Section 48.2, shall be no less than 95 percent of the Maximum Power reported to the Energy Commission.

The following performance data and information shall be certified and provided to the Energy Commission.

 

The PTC Energy Rating consists of predicting PV module performance under all realistic conditions and selected reference days: hot sunny day, hot cloudy day, cold sunny day, cold cloudy day, and a nice day. An IEC Standard that would define a common approach is under development. TÜV Rheinland PTL will be ready to provide the PV modules Energy Rating service as soon as the standard is released.

Sandia National Laboratories’ PV module characterization procedure was transferred to TÜV Rheinland PTL in 2006. This effort was made to meet industry requests for independent module performance testing that provides the module parameters (coefficients) required by the Sandia performance model. The performance model and outdoor measurement procedures, developed by Sandia, have been validated by the National Institute for Standards and Technology (NIST) and TÜV Rheinland PTL.