Laboratory for Photovoltaic Systems

Research on photovoltaic systems has been carried out at the Laboratory for Photovoltaic Systems (PV Lab) of Bern University of Applied Sciences in Burgdorf since 1988. The core competencies of the dozen or so specialists working at the PV Lab include analysing the long-term behaviour of PV systems in terms of safety, reliability and energy output. Special emphasis is placed on inverters whose behaviour on the power grid is being investigated at the PV Lab.

Core competencies: testing, measuring and analysis

PV systems have evolved from niche to mainstream products. Along with hydropower, they are set to soon become one of the key pillars of the energy supply in Switzerland. The challenges of applied research in this field have changed with time. While the goal in the 1990s was demonstrating that PV systems could reliably generate power for longer than five years, today the key issues include safety (e.g. fire protection) and grid conformity. Thanks to its commercial success, photovoltaics technology is continually penetrating new markets. Each new application presents new challenges and risks. BFH’s PV Lab has continued to focus on its core competencies: it performs testing and analysis based on application-relevant scenarios which PV planners and installation engineers cannot undertake themselves. The PV Lab is also continually developing new measuring concepts and devices for this purpose.


The PV Lab also makes its knowledge and expertise available to the public and private sectors. Its range of services includes:

  • Inverter and PV system testing (efficiency, electromagnetic compatibility (EMC), function tests, damage analysis, analysis of fire scenarios)
  • Testing of inverters in relation to requirements for connection to the distribution grid (network and system protection, fault ride-through, active and reactive power control)
  • Measurement of battery systems in collaboration with the BFH Energy Storage Research Centre
  • Measurement of line and field-related electromagnetic faults related to PV systems
  • Analysis of PV modules in the laboratory and in the field (characteristic curve measurements, thermographic and electroluminescence measurements, potential-induced degradation PID)
  • Reflection and glare measurements
  • Measurements in the High-Voltage Systems Lab (insulation strength, resistance against direct and indirect lightning strikes)
  • Research partnership for Innosuisse projects
  • Research-related calculations, studies and expertise

All services are carried out – as far as possible – with students from Bern University of Applied Sciences for training purposes. Unless copyright-protected by an industry partner, research findings are made public in the form of publications.


The PV systems field of research covers concept-related questions involving PV modules and module-like components (for example, connectors, diodes, smart module components, cell and stringing concepts).

Specially selected areas of research

  • Applied research for SMEs (Innosuisse)
    • Support with the development of new products and improvement of existing ones
    • Quality assurance measurements
    • Testing of safety features
  • Outdoor test benches with individual module monitoring
  • Indoor test benches
    • Characteristic curve measurements with a flasher
    • Analysis of cell breakage using electroluminescence
    • Analysis of ageing of cell breakage using ultraviolet fluorescence
    • Steady-state analysis with sun simulator (hotspots, warming effects)
  • High-voltage and high-current lab for component tests
  • Long-term monitoring and quality tests for PV systems
  • Benchmarking of PV modules


BFH’s inverter lab specialises in three areas:

  • Grid connection of inverters (smart-grid functions of inverters, network and system protection, fault ride-through FRT)
  • Electromagnetic compatibility (EMC)
  • Efficiency measurements

In addition to purely PV-grid connection inverters, off-grid and PV battery systems are also tested. Close collaboration with the High-Voltage Systems Lab enables testing of inverters’ resilience against direct or indirect lightning strikes. The Laboratory for Photovoltaic Systems is part of the BFH Energy Storage Research Centre in Biel which means it has access to high-quality infrastructure for testing batteries and related systems.

The IT backbone of the inverter lab is the browser-based MUSCLE concept developed at BFH. This open-source concept uses Python programmes which control simulators and read measuring devices via embedded systems.


Studies and expert reports are often produced at the Laboratory for Photovoltaic Systems when applied research topics are explored as part of bachelor or master theses. The theses can be supplemented with practical experiments or the development of software or simple tools. Topics include:

  • Energy output
  • Self-consumption of solar power
  • Glare from glass surfaces
  • Simulation of PV system components (e.g. electrical simulation of bypass diodes in PV modules)

BFH’s Laboratory for Photovoltaic Systems has the following facilities:

  • A range of PV systems of various ages and based on different technologies
  • Inverter lab with programmable DC and AC sources and sinks for inverter testing up to 100 kVA
  • Test bench for module inverters and power optimisers
  • High-Voltage Systems Lab for direct and indirect lightning strikes, surge-voltage generator (direct and alternating current applications)
  • Stationary and mobile testing facilities for measuring electromagnetic fields
  • Sun simulator and flasher
  • Electroluminescence measuring equipment
  • Ultraviolet fluorescence measuring equipment
  • Mobile test equipment (characteristic curve measuring devices, thermographic cameras)
  • Climatic chambers for humidity/heat/cold tests
  • Connector test bench for analysing the ageing of PV connectors

The extensive testing equipment of the BFH Energy Storage Research Centre in Biel can also be used.

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