Electroluminescence image analysis of a photovoltaic module under accelerated lifecycle testing

Area of Science:

• Materials Science
• Electrical Engineering
• Renewable Energy

Background:

• Electroluminescence (EL) imaging is crucial for identifying electrical defects in silicon (Si)-based photovoltaic (PV) modules.
• Defects like cell cracking can significantly reduce PV module performance.

Purpose of the Study:

• To evaluate the effectiveness of EL imaging in assessing PV module degradation over time.
• To establish a correlation between EL image analysis and module power conversion efficiency.

Main Methods:

• A commercial polycrystalline Si PV module underwent accelerated lifecycle testing.
• EL imaging was performed periodically to monitor changes.
• Pixel intensity distributions within individual PV cells were analyzed.

Main Results:

• A direct correlation was found between EL image analysis and module conversion efficiency.
• A 2.5% decrease in normalized EL intensity corresponded to a 0.35% drop in power conversion efficiency.
• The analysis demonstrated a 2.3% relative decrease in efficiency.

Conclusions:

• EL imaging provides a rapid, unsupervised method for assessing PV module health.
• This technique can reliably detect performance reductions linked to cell defects.
• EL imaging analysis offers an efficient alternative to traditional visual inspection of PV modules.