Evaluación y análisis de defectos en módulos solares fotovoltaicos

Abstract

The primary aim of this doctoral thesis is to identify, measure, and analyze defects in monocrystalline silicon photovoltaic modules. While some defects may only have aesthetic implications, others can lead to critical failures. Correct evaluation and determination of these defects are crucial for maintenance decisions, as they can diminish the production capacity of the entire installation and significantly impact its profitability. The thesis begins with a systematic review of defects affecting commercial photovoltaic modules, focusing on monocrystalline silicon technology, the most widespread module technology in current installations, particularly in Spain. Key defects documented in scientific and technical literature include snail tracks, cell fractures, hot spots, bubbles, and encapsulant discoloration. A specific protocol for inspecting photovoltaic fields was developed based on these findings. This protocol was applied to a 100 kW typical solar photovoltaic power plant located in the province of León, Spain. To organize the collected data, maintain a documentary record of the plant's condition, and design suitable inspection and maintenance procedures, a Geographic Information System (GIS) application was used. By using this application, it was possible to record defects observed at the cell level during inspections, document electrical parameter measurements at the module level, and efficiently access images and thermography of each module. After conducting three consecutive annual measurement campaigns at the test plant, it was inferred that certain types of defects, typically associated only with aesthetic aspects of the module, can affect performance and promote subsequent failures. This is particularly true for discolorations and snail tracks. Furthermore, monitoring the electrical parameters of modules reveals that those affected by certain defects show progressive deterioration in characteristics, potentially impairing the overall plant performance. However, the results are not conclusive in all cases. The contributions of this work to the development of photovoltaic solar technologies and their maintenance are deemed significant and will enable new research impacting the design, maintenance, and optimization of photovoltaic solar plants.