Bill-of-Materials Tester

The development of new materials for photovoltaic modules requires extensive testing of their performance under realistic conditions. Laboratory measurements under standard test conditions provide only limited information, covering only a special operating mode. Fraunhofer CSP has developed a test setup with which several PV mini-modules can be tested under identical conditions both in the laboratory and outdoors, thus bridging the gap between laboratory and realistic operation.

BOM Tester outdoor test setup
© Fraunhofer CSP
Outdoor test setup: Conditions comparable to field operation.


  • Mobile test station for use in laboratories and outdoors
  • Simultaneous measurement of up to 16 mini-modules under identical conditions, such as intensity, irradiation angle, temperature
  • Use of precise measuring electronics with 4-quadrant measurements for data acquisition

Benefits and Advantages

  • Reduction of test costs for material screenings
  • Bridging the gap between laboratory measurements and yield in open field
  • Detailed quantification, e.g. of degradation effects, through precise measurement electronics

Application Examples   

  • Evaluation of glasses and ARC layers or module technologies, e.g. half cells
  • "Outdoor" measurement: Realisation of relevant operating conditions for free field assessment, e.g. incidence of diffuse light, modified angles, dependence on daylight
  • "Indoor" measurements: Rapid evaluation of material variations and reference measurements under standard test conditions