1 Scope
The IEC 61853 series establishes IEC requirements for evaluating PV module performance based on power (watts), energy (joule or watthours) and performance ratio. It is written to be applicable to all PV technologies, including bifacial PV modules, but can be unsuitable for any technology where the module performance changes with time (e.g. modules change their behaviour with light or thermal exposure), or which experience significant non-linearities in any of their characteristics used for the modelling.
The purpose of this second part of IEC 61853 is to define procedures for measuring the effects of angle of incidence of the irradiance on the output power of the device, to determine the operating temperature of a module for a specific set of ambient and mounting conditions and measure the spectral responsivity of the module.
NOTE 1 In the IEC 61853 series, spectral responsivity measurements are used for calculating spectral correction factors, in combination with standardized and location-specific spectral irradiance data from Part 4. Then they are applied in the energy rating calculation described in Part 3 to account for mismatches from the reference AM1.5 spectrum with respect to what can be detected by a reference irradiance detector (e.g. a pyranometer). It is important to note that without spectral responsivity data, the resulting deviations in the energy rating calculation can be significant; however, spectral responsivity alone does not provide information on energy gains or losses.
The described measurements are required as inputs into the module energy rating procedure described in IEC 61853‑3[28]1. Results of the measurements described in this part, however, can also be used for other purposes, where relevant, e.g. yield prediction with commercially available simulation tools that require spectral responsivity or angle of incidence effect.
PV modules to be installed onto buildings (either as building integrated or as building applied photovoltaics, BIPV or BAPV, respectively) can exhibit very peculiar spectral, optical and thermal properties. This document can be applied for the energy rating of these modules and their specificity is illustrated in Annex A: however, it is important for the reader to be aware that in some of these circumstances the thermal performance of the module under test can be severely affected by the specific mounting configuration.
NOTE 2 IEC TS 63126[1] presents an informative annex that can be used as a guidance to get information on operating module temperatures for several locations and mounting configurations. From the 98th percentile maps provided therein, the reader can infer a temperature offset that could be applied to evaluate the effect of mounting configurations to the operating temperatures to be used in the energy rating calculated in Part 3 of this series. The estimation of this offset, however, is outside the scope of this document.