IoT System Based on Artificial Intelligence for Hot Spot Detection in Photovoltaic Modules for a Wide Range of Irradiances

Sensors (Basel). 2023 Jul 28;23(15):6749. doi: 10.3390/s23156749.


Infrared thermography (IRT) is a technique used to diagnose Photovoltaic (PV) installations to detect sub-optimal conditions. The increase of PV installations in smart cities has generated the search for technology that improves the use of IRT, which requires irradiance conditions to be greater than 700 W/m2, making it impossible to use at times when irradiance goes under that value. This project presents an IoT platform working on artificial intelligence (AI) which automatically detects hot spots in PV modules by analyzing the temperature differentials between modules exposed to irradiances greater than 300 W/m2. For this purpose, two AI (Deep learning and machine learning) were trained and tested in a real PV installation where hot spots were induced. The system was able to detect hot spots with a sensitivity of 0.995 and an accuracy of 0.923 under dirty, short-circuited, and partially shaded conditions. This project differs from others because it proposes an alternative to facilitate the implementation of diagnostics with IRT and evaluates the real temperatures of PV modules, which represents a potential economic saving for PV installation managers and inspectors.

Keywords: IoT System; Mobilenet; Resnet50; deep learning; infrared thermography; machine learning; photovoltaic installation; random forest.

Grants and funding

This work was fully funded by the Instituto Tecnológico de Costa Rica (TEC) through the project “Identificación de Fallas en Instalaciones Solares Fotovoltaicas”, funding number 1360051. TEC was supported by State of Costa Rica as one of the public estate universities. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.