Testing of PV modules in outdoor conditions

For the purpose of research of performance of various PV modules we have built an outdoor PV monitoring site, which is located on the roof of Faculty of Electrical Engineerig. The site has the capability to measure all major performance parameters of PV modules (I-V curve, power, current and voltage in MPP point, open circuit voltage, short circuit current, efficiency, ...) at various weather conditions.

We also provide long-term monitoring of PV modules under realistic conditions for the period of one month to one year. We evaluate:

  • energy produced (daily, monthly)
  • temperature (current, average, maximum)
  • irradiance (current, average, maximum)
  • energy yield

 Besides module measurements, weather data are also monitored:

  • solar radiation on different planes
  • air temperature
  • air pressure
  • wind speed and direction


Each PV module is connected to its maximum power point tracker (MPPT) that transfers the energy from the module to a common bus. From the latter the energy goes through the inverter through to the grid. In addition to safety, galvanic separation in the trackers also allows the module to operate at an elevated potential. Each tracker also has a switch that on request connects a module to an IV curve tracer. Each MPPT is also in charge of temperature measurement of each module.

Key components of the system, such as tracker, IV meter and weather station, have been developed in our laboratory.




  • Four wire connection for each PV module
  • IV curve measurement with an advanced unit
  • Class A irradiance sensors
  • Adjustable IV scan time per each PV module


  • Easily expandable to multiple of 16 channels
  • Open/Short circuit or MPP load conditions
  • Option for supplying module with bias voltage (to study PID)
  • Multiple temperature sensors on each module
  • MODBUS® interface for pyranometers
  • Bias voltage source for PID testing


  • Grid connected system - no energy is wasted
  • Fast consecutive IV curve scanning
  • Simultaneous acquisition of temperature and MPP parameters for all PV modules

Custom solution

  • We offer module testing at our sites
  • We can set-up test site according to your wishes




Basic properties

  • 16 channels in standard configuration
  • Easily expandable to multiple of 16 channels
  • PV module max. ratings: 200 V / 17 A / 550 W
  • Bias voltage up to more than +/- 1 kV
  • Up to 8 temperature sensors on each module (±1 °C)
  • IV scan accuracy: voltage: ±0,1 %, current: ±0,2 %
  • IV scan time of each PV module: <1 s

Product Brochure



For additional information please contact:

  • Marko Jankovec, E-mail: Marko.Jankovec[at]fe.uni-lj.si, Phone: +386 1 4768 931