A research group from Tunisia’s University of Tunis has developed a low-water evaporative cooling system for PV modules operating in arid climates. The system consists of three layers of jute fabric and an Internet of Things (IoT)-controlled water pump.
“The novelty of our research rests on three key pillars that have never been combined before,” corresponding author Mahmoud Chaabani told pv magazine. “First, we engineered a three-layer jute fabric with an orthogonal 0°/90° fiber orientation to maximize capillary-driven water distribution. Second, instead of continuous wetting, we introduced a deterministic IoT threshold algorithm. Third, this is the first field validation under extreme real-world desert conditions.”
Chaabani said the combination of biodegradability, near-zero parasitic power consumption and closed-loop IoT control makes the technology a practical solution for off-grid systems in arid regions.
“We are also preparing a large-scale, megawatt-level industrial pilot to validate the water distribution network for thousands of panels,” he also explained. “We are planning accelerated aging tests and exploring chemical treatments or composite natural fibers, such as modified flax and hemp blends, to extend service life.”
The cooling system consists of three layers of jute fabric attached directly to the rear surface of a 30 W monocrystalline PV module. The layers are arranged in alternating 0° and 90° fiber orientations to promote uniform water distribution through capillary action, while a serpentine network of perforated polyethylene tubes supplies water to the fabric.
An ESP32-based controller activates a small, PV-powered pump for 72 seconds when the module temperature exceeds 55 C and power output falls below 22 W. The system then enters a 1,800-second standby period.
“This reduces water consumption to just 0.14 L/h/m², which is 86% less than previous natural-fiber approaches such as burlap,” Chaabani said.
To evaluate the system, the researchers compared the cooled module with an identical uncooled reference module. The outdoor experiment was conducted over three consecutive clear-sky days, from July 14 to 16, 2025, at an arid test site in southern Tunisia at an altitude of 238 meters. Both modules were installed at a fixed tilt angle of 30°, while three thermocouples positioned at the top, center and bottom of each module monitored rear-surface temperatures.
The researchers recorded voltage and current at one-second intervals, performed current-voltage sweeps every five minutes, and measured irradiance and weather conditions. During the tests, peak irradiance reached 848 W/m², while the highest ambient temperature was 45.4 C.
“We were genuinely surprised by two aspects,” Chaabani said. “Thermally, the system achieved a 21.4 C temperature reduction, decreasing from 75.5 C to 54.1 C, while maintaining a spatial temperature variation of less than 2 C across the panel, exceeding our simulation predictions. Electrically, the 40.44% relative power gain was not solely attributed to the temperature reduction. The cooling also significantly improved the fill factor by 14.5%, increasing it from 0.62 to 0.71, while reducing the series resistance from 0.45 Ω to 0.32 Ω..”
“From a hydrological perspective, our intermittent pulsed system achieved an 81.3% water recovery rate, with only 0.026 L/h/m² lost to actual evaporation – proving that evaporative cooling does not have to be a water-wasting technology,” he added.
The researchers said they are now working to integrate a predictive machine-learning layer into the system’s IoT architecture and embed metaheuristic optimization algorithms.
“This will allow the system to automatically adapt to changing irradiance, ambient temperature, and humidity, ensuring maximum power gain with minimal water consumption under all conditions,” Chaabani said.
The team did not assess the system’s costs or provide a techno-economic analysis.
The system was presented in “Optimization of photovoltaic efficiency in arid regions via IoT-controlled jute fabric evaporative cooling,” published in Scientific Reports.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: [email protected].
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: [email protected].
Comments
Please login to comment
The new issue of pv magazine Global is out now!
Available in print and digital – get your copy today!
Martedì, 22 Settembre 2026
11:00 – 12:00 CEST, Roma
Monday, October 26, 2026
10:30 am – 11:30 am CEST, Berlin, Paris, Madrid
Tuesday, September 15, 2026
5:00 pm – 6:00 pm CEST, Berlin, Paris, Madrid
A two-day conference in Austin, Texas, bringing together leaders in US solar manufacturing, equipment specification, and factory execution.
Saudi Arabia is accelerating its clean energy transition—join the SunRise Arabia Clean Energy Conference 2026 in Riyadh to explore how solar PV and energy storage are powering its digital economy.
pv magazine USA hosts its multi-day virtual event on U.S. solar and energy storage, covering domestic manufacturing, distributed energy and the growing role of solar-plus-storage in meeting AI-driven power demand.
You have no items in your basket.
