Mobile Photoluminescence Inspection for Solar Modules

TO-205 • PT 1.2898 • As of 05/2025
Institute of Energy Technologies (IET)
Helmholtz Institute Erlangen-Nürnberg (IET-2/HI ERN)

An innovative, mobile photoluminescence system for rapid, contactless, and high-resolution quality assessment of solar cells directly on site-including drone-based deployment.

Technology

This technology is a mobile photoluminescence (PL) inspection system specifically designed for on-site quality assessment of photovoltaic modules. At its core, the system utilizes an array of high-power LEDs as a controllable light source to excite the solar cells, causing them to emit characteristic photoluminescent light. This emission is then captured by a sensitive digital camera equipped with a long-pass filter, which isolates the relevant wavelengths and ensures accurate detection of defects and performance losses.

Problem addressed

Fast and reliable assessment of solar module quality in large photovoltaic installations is currently complex, often limited to laboratory settings, and typically requires intervention in the electrical system-a significant time and cost factor for maintenance, commissioning, sales, or damage analysis.

Solution

Our technology enables mobile use of the photoluminescence method outside the lab:

· A specially developed, lightweight, and modular illumination unit with individually controllable LEDs and a matching camera with a long-pass filter precisely and automatically detects defects and performance losses in solar cells.
· The entire unit can be flexibly mounted, for example on drones, allowing for rapid, large-area, and contactless inspection during the night - even in hard-to-reach locations.
· Unlike conventional electroluminescence methods, no intervention in the power circuit is required, greatly simplifying and speeding up the process.
· The system delivers immediate digital analysis and, thanks to its modular design, is highly portable and scalable.

Benefits and Potential Use

· Maintenance and routine inspection of large-scale photovoltaic plants
· Quality assurance during installation and commissioning of new solar systems
· Damage analysis and documentation for insurance purposes
· Evaluation and valuation in the sale or acquisition of existing installations
· Research and development in solar cell and module testing

Development Status and Next Steps

The technology is at Technology Readiness Level (TRL) 6–7: A functional prototype has been successfully tested under real-world conditions. We are looking for industry partners to further develop and commercialize this innovation. Contact us for more information and set new standards in the maintenance and quality assurance of photovoltaic systems.

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