Outdoor Performance Lab

Reliable measurement data are essential for determining 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 information on the possible degradation and the expected lifetime yield of PV modules in different climatic zones and allow their comparative evaluation.

At our outdoor test sites, we test PV modules and their components 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.

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.

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.

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

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

• 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