Created by M.L., OST, on 19.03.2025
- Description: A DC current is applied to the PV modules, which causes the cells to emit light, which is detected by a charged silicon camera. Regions with high signal are intact, whereas damaged areas will remain dark, allowing for defect localization [1].
- Equipment: DC current source, charged silicon camera with high resolution and a high pass edge filter at 850 nm to 950 nm.
- Requirements: Measurements to be performed in the dark (at night, or with a cover).
- Gained insights: Detection and location of contact failures like cell (micro-) cracks, shunts, inactive PV cells or sub-strings, printing problem, broken parts, potential induced degradation (PID) defects, soldering defects, failed bypass diode. May detect hot spots, delamination, glass breakage to a certain limit. Due to the combination of low temperatures and heavy mechanical loads (wind and snow), defects such as micro-cracks are expected to be more common in alpine regions [2–4].
- Advantages: High resolution, detection of cell damages as well as interconnection issues.
- Disadvantages: Need for DC source and dark conditions.
- Effort:
- Global: high.
- Costs: high.
- Time: high.
- Providers (non-exhaustive list):
- ENVARIS GmbH: https://envaris.de/services/photovoltaik-elektrolumineszenz/
- Photovoltaikbüro: https://photovoltaikbuero.de/dienstleistungen/pvcheck-fehlersuche/[ML2]
- Daylight electroluminescence: https://solarzentrum-stuttgart.com/EL_Messung/
- 3S Swiss Solar Solutions: https://www.3s-solar.swiss/services
- Links:
- Brief explanation of EL: https://www.pveducation.org/pvcdrom/characterisation/electroluminescence
- Additional notes:
- Drone-based EL imaging is being developed and might significantly reduce the costs of this measurement in the near future. Lock-in amplification can be used to measure during daytime.
- Regular EL measurements would be of interest for tracking the formation of micro-cracks in the cells due to snow coverage and/or increased environmental stressors in Alpine regions.
References
- Jahn U, Herz M, Köntges M, Parlevliet D, Paggi M, Tsanakas I, et al. Review on infrared and electroluminescence imaging for PV field applications. International Energy Agency (IEA); 2018.
- Gassner A. Alpine PV: Stressors and module testing strategies 2025.
- Seigneur H, Schneller E, Lincoln J, Ebrahimi H, Ghosh R, Gabor AM, et al. Microcrack Formation in Silicon Solar Cells during Cold Temperatures. 2019 IEEE 46th Photovolt. Spec. Conf. PVSC, Chicago, IL, USA: IEEE; 2019, p. 1–6. https://doi.org/10.1109/PVSC40753.2019.9198968.
- Schneller EJ, Seigneur H, Lincoln J, Gabor AM. The Impact of Cold Temperature Exposure in Mechanical Durability Testing of PV Modules. 2019 IEEE 46th Photovolt. Spec. Conf. PVSC, Chicago, IL, USA: IEEE; 2019, p. 1521–4. https://doi.org/10.1109/PVSC40753.2019.8980533.
