CalLab PV Modules

The CalLab PV Modules at Fraunhofer ISE in Freiburg is one of only five accredited calibration laboratories for PV modules worldwide and has established itself internationally as a reference for module characterization.

Precision

With an accredited measurement uncertainty (Pmpp) of only ±1.1 % for monofacial PV modules and ±1.4 % for bifacial modules, CalLab PV Modules is one of the most precise laboratories in the world. This is ensured by extensive measures to guarantee the quality of procedures and equipment. The use of primary calibrated reference cells from the German Federal Institute of Physics and Metrology (PTB) is the basis for offering the lowest possible uncertainties.

Reliability and Experience

Since the early 1980s, Fraunhofer ISE has been involved in the measurement of solar cells and modules, thus creating the basis for a world-leading quality infrastructure in the field of photovoltaics. From these activities, a separate laboratory for the performance characterization of PV modules gradually developed. The first measuring device (flasher) for measuring full-format modules was put into operation at the end of the 1990s. In 2006, CalLab PV Modules was accredited as a testing laboratory according to IEC 17025, followed by accreditation as a calibration laboratory in 2015. Today, the laboratory can demonstrate a stable calibration level over many years.

Uniqueness

Together with our TestLab PV Modules, which is also accredited, CalLab PV Modules forms a globally unique testing environment for the calibration, reliability assessment and certification of PV modules. Every year, over 7,000 modules are characterized in the laboratory for various purposes, including quality assurance for customers, module certification, and damage and degradation assessment. This has led to a wealth of experience regarding the specific requirements for measuring the performance of different module generations.

The CalLab PV Modules offers highly precise calibrations of PV modules at standard test conditions (STC) according to the international standard IEC 60904-1 Ed. 3 (2020-09). The measurement uncertainty of only ±1.1% and our quality assurance places us among the leading international calibration laboratories. CalLab PV Modules is accredited as a calibration laboratory according to DIN EN ISO/IEC 17025:2018 (Accreditation Certificate D-K-11140-02-00, ILAC-MRA).

To ensure a stable calibration level with the lowest possible measurement uncertainties on our testing systems, we have been consistently implementing extensive internal and external quality assurance measures for many years. We are continuously developing and adapting these measures to meet the challenges arising from the further development of cell and module technology.

The graphic on the left shows an example of the results of these elaborate routines. It shows the results of regular reference measurements against primary calibrated cells from the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig.

A stable and reliable calibration level is an advantage for our customers, among other things because the power degradation of modules can be determined very precisely, provided that the customer has given some modules to our laboratory for measurement when the system was installed (e.g. in the case of a warranty claim).