Outdoor Performance Lab

Precise Evaluation of PV Modules

Reliable measurement data are essential for deter-mining the performance of PV modules. Fraunhofer ISE’s solar test sites enable precise collection of all relevant monitoring data. Together with classical laboratory tests, they provide valuable infor-mation on the possible degradation and the expected lifetime yield of PV modules in different climatic zones and allow their comparative evaluation.

Our Services for Module Manufacturers, Operators, Investors, Banks and Insurance Companies:

  • initial comprehensive module characterization in the laboratory
  • fixed, single-axis or dual-axis tracking module installation
  • high-frequency, precise recording of module power, current-voltage characteristics, meteorological data and other operating parameters in the field
  • outdoor measurements in Freiburg / Merdingen, on Gran Canaria and in the Negev desert
  • customized evaluations and useful, independent reports
  • determination of degradation indicators using comparative measurements on pre-aged and new modules
  • benchmarking of different module types against reference modules or our inventory of test samples
  • climate and site-specific energy rating

At our outdoor test sites, we test PV modules and their com-ponents for manufacturers and operators. The actual yield, reliability and aging behavior of new module types have a significant influence on the economic viability of solar power plants and the costs of the energy transition. Our independent analyses facilitate the selection of durable components for plant operators, investors, banks and insurance companies.

Outdoor Performance Test Fields

In Merdingen, 15 km west of Freiburg in Germany, one of the largest test fields for solar energy systems in Europe is being built. On an area of three hectares, Fraunhofer ISE will be testing the performance and reliability of components and systems in real-life operation. Other test sites exist in Gran Canaria (Spain) and the Negev Desert (Israel), allowing testing in other climates.

Outdoor Performance Testfeld in Freiburg / Merdingen
© Fraunhofer ISE
Visualization of the Solar TestField with different solar system setups in Merdingen near Freiburg, Germany.
Outdoor Performance Testfeld Gran Canaria
© Fraunhofer ISE
Outdoor Performance Test Field on the premises of the Instituto Tecnológico de Canarias (ITC) in Pozo Izquierdo, Gran Canaria, Spain.
Outdoor Performance Testfeld Negev
© Fraunhofer ISE
Outdoor Performance Test Field on the grounds of Ben-Gurion University of the Negev, Sede Boqer, Israel.

Precise Benchmarking for Innovative PV Modules

The solar test sites are ideal for testing innovative technologies, such as bifacial modules, TOPCon technology, hetero-junction technology (HJT), perovskite PV, organic PV (OPV) and tandem PV. Under outdoor conditions, comparative measurements can be performed with reference modules from Fraunhofer ISE as well as with competitor products. Depending on the technology and application, different questions arise. Thus, we customize test programs and accompanying analyses with our clients as required.

Detailed Meteorological Data Collection

All test sites have comprehensive meteorological data collection:

  • different sensor types for solar irradiation (pyranometers, reference cells)
  • separation by irradiation type (direct, diffuse)
  • different orientations (horizontal, inclined towards south, tracking)
  • spectroradiometers, cloud cameras
  • air temperature, pressure, humidity
  • wind speed and direction
  • pollution levels on surfaces

Comprehensive Performance Analysis

We combine the monitoring data from the outdoor per-formance test site with precision measurements from the accredited CalLab PV Modules, accelerated aging tests from the accredited TestLab PV Modules as well as with highly sensitive degradation analyses using processes which we have developed. In all, Fraunhofer ISE offers a unique plat-form for comprehensive performance analysis:

  • precision measurements in the laboratory under standard conditions and according to IEC 61853 (Energy Rating)
  • reproducible preconditioning in our TestLab PV Modules (accelerated aging in climatic and UV chambers)
  • direct comparison of aged and new modules in real operation with relative measurements for early identification of technology, material, and design-specific degradation risks
  • combination with parameter-based simulation calcu-lations for module performance and energy rating for product optimization
  • reduction of the overall uncertainty for module perfor-mance and lifetime yield
Flasher für bifaziale Module am Fraunhofer ISE CalLab PV Modules.
© Fraunhofer ISE
Flasher for bifacial modules at Fraunhofer ISE CalLab PV Modules.
Flasher am Fraunhofer ISE CalLab PV Modules.
© Fraunhofer ISE
Flasher at Fraunhofer ISE CalLab PV Modules.
Scanning acoustic microscopy (SAM)
© Fraunhofer ISE
Scanning acoustic microscopy (SAM) wird als zerstörungsfreie Untersuchungsmethode bei der Defektanalyse an Vollformat-Modulen genutzt.

Further Offers at the Outdoor Performance Test Site in Merdingen:

  • analyses of the electricity and agricultural yield of agrivoltaic (APV) systems
  • characterization of concentrating PV modules (CPV)
  • measurements on inverters and PV battery systems
  • qualification of tracked PV systems
  • measurements on integrated PV installations, e.g., on noise barriers


More Information on this Research Topic

Accredited Lab

CalLab PV Modules

Callibration of photovoltaic modules

Accredited Lab

TestLab PV Modules

Quality and reliability testing for photovoltaic modules

Flyer: Outdoor Performance Lab