Much like infrared thermography, Electroluminescence testing or EL is an image based form of analysis used in the Photovoltaic solar industry. Although, this is where the similarities begin to deviate.
Where thermography works best is under high irradiance sunny conditions and a heavily loaded PV system to detect operational generated heat. Electroluminescence Testing requires the opposite to work. Dark, no to low-light conditions with the system turned off. In fact! We bring the power to the solar array.
This is a unique characteristic that makes Electroluminescence Testing possible. Electroluminescence Testing is a procedure that involves injecting DC power into a solar module or string enabling illumination of the cells to occur. The creation of illumination enables a photo to be taken which reveals the electrical path of the photovoltaic circuitry. If dark patches or lines appear in the Electroluminescence Testing photo taken this is a sign that a lack of voltage is present in the location where light is not visible. In simple terms, dark or black areas = no or restricted current flow which means a failure has occurred.
Using this approach with the correct knowledge and technical understanding of PV anomalies and silicone cell characteristics, at Scanpro we use this information to track down the source of what has caused the break, and why.
Electroluminescence Testing can be thought of a bit like an x-ray image of a person. With an x-ray we can see through the body and observe the skeleton structure of the human. With Electroluminescence Testing, we can see the flow and structure of voltage and current path throughout the cells that make up the module. The light emitted is unable to be seen with the human eye and the microcracks are unable to be seen with the human eye.
At ScanPro, we use a specially modified camera to do that. But, once the image is taken observing the image on a laptop or computer it begins to reveal the true operating state of the system.
The visual data extracted from this type of inspection can reveal a huge amount of information about the current state of the module once it arrives onsite.
We can observe manufacturing process defects, material handling flaws, logistical handling flaws, installation flaws and environmental impact exposure. This is information that is not able to be revealed using infrared thermography.
In-field Electroluminescence Testing is a very popular method in the solar industry to address quality control and quality assurance requirements. PV modules are the most expensive component in a solar installation and they are also fragile and susceptible to damage if not handled correctly.
Electroluminescence Testing among other forms of testing are being utilised by the solar industry to manage and control the correct delivery of service quality for investors, asset owners and insurance firms.
Electroluminescence Testing has the ability to identify:
- Cracked silicone cells
- Excessive pressure or bending
- Hailstone storm strikes
- Sub-circuit failure
- Bypass Diode failure
- Incorrect installation
- Mishandling – Poor logistics or installation practices
- Excessive wind damage – flexing
- Visual damage
Value this Electroluminescence Testing delivers to our clients:
- Confidence in quality delivered
- Reassurance damage has not been sustained
- Grasp a deeper understanding of PV module/ solar panel health
- Maintain compliance to contractural O&M obligations
- Address compliance to commissioning test requirements
- Hailstorm damage can be located and mapped out
- Strong wind damage can be found
- Track cell degradation over time
- Supply a fully independent solution to address disagreements and concerns
- Capability to supply quality control needs
- Consultation and advice
- Visual inspection, analysis and annotations supplied
Deliver confidence, build credibility and support investment.