// PV testing facility

Since 1989, ZSW has been operating a testing facility for solar modules and solar power systems in Widderstall near Merklingen in the Swabian Alb. The site, which is located about 750 metres above sea level, is characterised by excellent solar irradiation conditions and cold winters with considerable amounts of snow. Here, PV systems with inverters are operated as electric stand-alone or grid-connected systems, and the energy yields from various solar power technologies are recorded in direct comparison. On behalf of manufacturers or financial institutions, PV modules are continually measured as part of international comparison tests, and the data on the performance behaviour as well as ageing effects are documented in databases for later evaluation.

Equipment and tests

  • Characterisation of PV components

o Meteo station with high quality irradiation and environmental sensors

o Performance ratio

o Spectral impact

o Low light and partial load behaviour

o Temperature coefficient

o The impact of transients, such as LID long-term ageing

o PID field test with leakage current measureme

  • Characterisation of PV systems

o Generator test rig

o Micro-inverters

o Shading

  • Building-integrated PV (BIPV)






Peter Lechner
+49 (0)711 78 70-254
Module test rig on ZSW's outdoor testing facility
Tracker with 3-fold concentration of sunlight for accelerated ageing tests