A Czech team developed an IoT system using MQTT to autonomously cool PV panels, increasing daily energy yield by 7.38% with a positive net energy balance.
A research team from the Czech Republic has developed a new Internet of Things (IoT) architecture specifically designed for active water cooling of PV panels, active cooling of PV panels.
“The architecture explicitly evaluates the net energy balance of the cooling process,” the team said. “The proposed system enables autonomous operation of individual cooling nodes while providing centralized coordination and trend-aware decision support capabilities at the fog level. This approach improves overall energy efficiency, reduces dependence on centralized hardware, and provides a scalable foundation for future integration of AI-based control strategies.”
The distributed IoT-based architecture integrates an autonomous ESP32-based microcontroller, a Raspberry Pi fog layer for real-time decision making and an optional cloud layer for long-term optimization.
The system uses a distributed IoT architecture with three layers, namely edge, fog and cloud. The edge nodes handle data collection, with sensors on the PV panels measuring temperature, electrical power, coolant status and environmental conditions.
The data is sent to a central controller via the MQTT message queue telemetry transport communications protocol. In the controller, the fog layer comes into action, which performs real-time decision making and activates a water pump based on thresholds not shared by the team. A cloud layer enables long-term analysis, but is not required for use.
An experimental study of the proposed IoT technology was conducted outdoors on a real 600W installation in an undisclosed location. In the experiment, two branches of the PV installation were equipped with the new IoT system, and two were not, which served as a reference. Data were collected for 52 days.
According to the results, the daily energy output of the cooled branch on a representative day was 818.61 Wh, while the uncooled reference branch produced 762.36 Wh. That represents an absolute gain of 56.25 Wh and a relative gain of 7.38%. “Taking into account the measured pump consumption of 6 W, the resulting energy return on investment (ROI) reached 1.07 on representative high irradiation days, confirming a positive net energy balance under real operating conditions,” the team added.
“The proposed architecture is fully wireless, scalable and independent of centralized hardware limitations,” they concluded. “By explicitly evaluating the net energetic effect of cooling rather than immediate peak gains, the study creates a practically deployable and energetically consistent framework for adaptive PV temperature management under dynamic climatic conditions.
The system was presented in “Energy-aware IoT architecture for active cooling of photovoltaic panels under dynamic weather conditions”, published in energy conversion and management: Scientists from the Czech University of South Bohemia in České Budějovice and the Czech Academy of Sciences took part in the study.
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