Toward low-carbon energy transitions: integrated optimization of solar panel output and safety using tracking and thermal management

Dual-axis solar tracking system

A dual-axis solar tracking system, developed to improve the efficiency of monocrystalline PERC solar panels, was placed at Pakistan Mint Colony, near Shalimar Town, Lahore, in April 2025. With this system, solar panels tracked where the sun was in relation to them in all directions through the day. Because of its geographical location at 31.5° N latitude, Lahore gets lots of sunshine in April and is suitable for solar experiments. A custom-made dual-axis tracker frame was built using aluminum alloy which prevented corrosion and helped decrease the overall weight. The system had rotational movements in two axes: azimuth (east-west) and elevation (north-south), which moved it in response to the position of the sun each day. Since Lahore’s latitude is 31°, the elevation axis of the solar furnace was also set to 31° in order to avoid shifting position of the sun during solar noon all year. The system was mounted on a flat panel with iron supports that were filled with concrete to block wind and any vibrations. For responsive and exact movement, two NEMA 17 stepper motors (Changzhou Stepper Motor Co., Ltd, Changzhou, China) were used which were controlled by Generic A4988 driver modules (China). Each subsystem (dual-axis tracker, reflector, cooling mechanism) was tested over a span of 5-7 days, ensuring that the tests were conducted under varying environmental conditions to account for daily fluctuations in irradiance and temperature.

Key components used

➢ Motors: NEMA 17 (× 2), 1.8°/step;

➢ Drivers: A4988 stepper motor drivers with microstepping;

➢ Power Supply: 12V 2A Direct Current (DC) adapter for motors, 5 V regulated supply for control.

An Arduino UNO R3 microcontroller (Arduino, Monza, Italy) controlled the panel’s movement based on input signals from four LDRs configured in a quadrant arrangement. Because of the barriers separating these LDRs, they could measure different brightness levels and then send signals to the Arduino as shown in Figure 5. To fit the differences, the system moved the panels to capture sunlight from its most direct direction. All the cables were tied up in a simple junction box that hosted the Arduino board, motor drivers and sensor inputs. The control circuit was powered by a 12 V battery through a 7805 voltage regulator (STMicroelectronics, Geneva, Switzerland) while the motors were powered directly by a 6 V DC adapter, as illustrated in Figure 5. Figure 6 demonstrates the control panel of the complete system.

Figure 5. 3D View of the Control Panel for the Complete Solar System. LDR: Light dependent resistor.

Figure 6. Control Panel of the Proposed Solar Energy System: Photographs were taken by the authors during the experimental phase of the study.

Reflector system with rain protection

The aim of this experiment was to determine whether integrating Mylar as solar reflectors onto a 20 W monocrystalline PERC solar panel would improve the panel’s energy output. As Mylar is highly reactive, a protective layer of Mylar was used in the experiment. As an additional measure, a transparent rain-protection cover was added to shield the system from unexpected rainfall, which frequently occurs in Lahore’s Mint Colony in April 2025, a period characterized by intense sunlight and occasional pre-monsoon rain. The position and angle of the reflectors were determined through continuous testing and set at 45° on the left and right edges of the panel to focus most of the incident light onto the active PV surface while avoiding hotspot formation. Polyvinyl chloride (PVC) sheets were used to hold the structure together, with the reflective materials fixed to the inner surfaces, and the entire assembly supported by aluminum struts welded to the base frame. Voltage, current, and temperature data were measured at one-hour intervals using sensors and multimeters during the workday, starting at 8:00 AM.

The greatest improvement in energy efficiency was observed during the morning and late afternoon hours, when the incident angle of sunlight was low and the reflectors helped to focus additional light onto the panel. At noon (12:00 PM to 2:00 PM), less reflection was required because the panels were already receiving near-maximum irradiance at solar noon, as shown in Table 3. Energy generation remained stable, and neither water accumulation nor soiling occurred due to the rain-protection cover during an unexpected light rain event on the third testing day. Side experiments showed that Mylar reflectors were ~6%-8% more effective than aluminum foil, attributable to their superior reflective properties.

Temperature-controlled cooling mechanism

The Temperature-Controlled Cooling Mechanism was set up to prevent solar panel performance from being affected by intense sunlight. Panel surface temperature was managed using a microcontroller to control water spraying in the airflow, eliminating the need for fans. The aim is to maintain a low operating temperature for a 20 W monocrystalline PERC panel by spraying a thin layer of water when its surface exceeds 35 °C, thereby enhancing efficiency.

The reservoir was a 5-liter plastic beaker. The ablative cooler was placed next to the solar panels to minimize the distance from the pump and covered with a lid to prevent dust and liquid evaporation. A small DC submersible pump (12 V, rated at 240 L/h) was installed inside the beaker. A PVC pipe (internal diameter ~6 mm) was connected to the pump output and routed above the solar panel, as shown in Table 5. At the pipe’s end, a spray nozzle or micro-holes (~1 mm) dispersed a mist evenly across the panel surface (~30 cm width), achieving full-surface cooling. A digital temperature sensor (housed in metal) was attached to the sunny side of the panel using thermal paste and tape, providing accurate real-time readings. An Arduino UNO continuously monitored the temperature from the DS18B20 and switched the pump on when the panel temperature reached or exceeded 35 °C, keeping it on until the temperature dropped below the set value (about 30-60 s).

The Arduino continuously reads the temperature from the sensor while the panel is on. If the temperature is below 35 °C, the pump remains off. When the temperature reaches 35 °C, the relay activates and the pump turns ON, sending water from the beaker through the pipe to be sprayed onto the panel via the nozzle or micro-hole. Evaporation of the water removes heat from the panel, providing cooling. Spraying continues until the temperature drops below 35 °C, at which point the pump turns off automatically.

A diode was placed between the relay coil and the Arduino to prevent back-EMF (Electromotive Force) from damaging the Arduino. All accessory wiring was insulated and kept out of the water to avoid short circuits. Low water pressure was used to prevent pooling or dripping along the panel edges. During peak sunlight hours, the panel temperature decreased by 5-10 °C, improving semiconductor performance and increasing voltage and current. Consequently, the cooled solar panel produced more energy each day compared with an uncooled panel.

Dual-axis solar tracking system

This proposed methodology in this project paired a 20-watt monocrystalline PERC solar panel with a dual-axis tracking system to maximize sunlight capture. In April, daily irradiance in Lahore averages around 5.5 kWh/m²/day. The tracking system adjusts the panel in the east-west (azimuth) and north-south (elevation) directions. Positioning the panel perpendicular to the sun increases solar exposure and energy generation. Measurements were taken at 8 AM, 12 PM, and 4 PM to evaluate average performance and compare it with a fixed-tilt panel at the same location and times, as shown in Table 6 and Figure 7.

Figure 7. Comparison of Power Output Between Fixed Panel and Dual-Axis Tracker.

At Morning Gain (8:00 AM), the fixed panel receives sunlight at an angle that limits energy capture. Tilting the panel with a dual-axis tracker toward the sun increases energy collection by up to 90%. At Midday Performance (12:00 PM), both fixed and tracked panels perform well because the sun is nearly overhead; however, the tracker still achieves a 9.7% improvement by maintaining perpendicular orientation. In the afternoon (4:00 PM, Afternoon Gain), fixed panels receive less direct sunlight, reducing efficiency, while the tracker’s azimuth rotation boosts efficiency by 71.8%, compensating for fluctuations. The fixed panel generated about 90 Wh/day, and the dual-axis system produced an additional ~38 Wh - over a third more, as shown in Figure 5. Table 7 summarizes supporting studies for this research.

Using the dual-axis tracking system greatly boosted the energy production of a 20 W PERC panel throughout the day. The largest improvement occurred during early morning and late afternoon hours, when fixed panels are less efficient, reaching up to a 92% increase in the morning. Overall, the system nearly doubled daily energy output, achieving 125 Wh under the typical sunny climate of Lahore in April, demonstrating significantly better performance. International studies and our results agree that dual-axis tracking is much more efficient for solar plants in Pakistan. Even in winter, the panel can generate minimal power from diffused sunlight in the morning and late afternoon, when sunlight strikes at a low angle. To maximize output during winter daytime, the panel tilt angle should be around 45º^[24,25].

While we recognize that irradiance and temperature fluctuations can affect solar panel performance, we reported the average performance gains across the test days. This approach effectively captures the system’s overall efficiency under typical conditions. Error bars were not included in some figures because the averaged data are sufficiently representative, and minor day-to-day variations do not significantly alter the conclusions. Nonetheless, variations in solar irradiance and ambient temperature could lead to fluctuating output, which may influence observed performance gains. For example, on days with higher irradiance, the system performed at its peak, whereas on overcast days, gains were relatively lower. To account for these variations, results were averaged over 5-7 days, with the standard deviation reported in the figures and tables.

Mylar reflector system with automatic rain protection

The Mylar reflectors were placed around a 20-watt Mono PERC panel to direct more sunlight onto the cells. Mylar film was chosen for its high reflectivity and durability. To protect the reflectors from rain, the system incorporates rain sensors that trigger servo motors or actuators to close or cover the reflectors during rainfall. This mechanism keeps the reflectors protected while ensuring sunlight reaches the panel, even under snow or rain. Tests were conducted in clear weather at three time points - 8 AM, 12 PM, and 4 PM - matching the evaluation windows shown in Table 8 and Figure 8.

Figure 8. Output Power Comparison with or without Mylar Reflectors Throughout the Day.

Improvements from Mylar reflectors were greatest at low sun angles, during both morning and evening. Panel output increased significantly at these times because sunlight was redirected onto the cells. At noon, a smaller rise of 25%-28% was observed, as the panels were already near peak efficiency. The reflectors continued to enhance performance by guiding light from the sides of the beam. As a result, the system produced an average of 110-115 Wh/day in April, a 28%-40% increase over the ~90-95 Wh/day measured without reflectors [Figure 7].

During simulated or real rainfall, the rain sensor triggered the servo motor to cover the Mylar sheets, preventing water streaks that scatter light, dust accumulation worsened by moisture, and permanent damage to the reflective film. The automated system ensured timely protection, keeping the reflectors intact and reducing maintenance time. Table 9 provides theoretical support and literature benchmarking.

The proposed findings align with global research and continue to recommend Mylar as a cost-effective choice for solar solutions in dusty and variable-weather regions, such as Punjab. A comparison of peak power output with and without Mylar reflectors is shown in Table 10.

The use of low-powered (< 0.5 W) controllers for the auto-retract system ensured almost negligible energy consumption. With system protection in place, users had access to the system year-round, making it suitable for semi-urban Shalimar Town, where power availability is inconsistent. Mylar reflectors on the panels improved sunlight capture when the sun was at a low angle. The automated rain protection system preserved the reflectors and prevented the weather from affecting performance. Overall, the system produced 110-115 Wh per day, approximately 18%-25% more than without reflectors, as shown in Table 8.

Effect of cooling mechanism on panel performance

The use of reflectors and other light-focusing tools can create risks such as panel overheating and hot spots. These issues can accelerate material degradation, shorten module lifespan, and, in extreme cases, pose safety hazards if not properly managed. To mitigate this, active cooling systems and precise reflector positioning are essential to maintain even light distribution and stable temperatures. Solar panel temperatures were monitored during peak sunlight at the Pakistan Mint Colony in Lahore in April 2025. Without cooling, panel surfaces often exceeded 42 °C. At such high temperatures, output voltage drops significantly due to increased internal resistance and reduced semiconductor performance. The cooling system was activated automatically when the panel temperature exceeded 35 °C. A microcontroller-controlled water spray nozzle, guided by a digital temperature sensor (DS18B20), delivered fine mist in short, frequent bursts for evaporative cooling. With this system, panel temperatures were maintained around 30-35 °C, as shown in Table 11. A comparison of power output with and without cooling is shown in Figure 9.

Figure 9. Comparison of Power Output with and Without Cooling of the PV Panel. PV: Photovoltaic.

Monocrystalline PERC panels may lose 0.4%-0.5% of their efficiency for every 1 °C rise in temperature above 25 °C. When the panel temperature reached 42 °C, the expected efficiency decrease was about 6%-7%, directly reducing the panel’s voltage and power output. The cooling system lowered the panel temperature to an optimal range, maintaining high voltage and preventing power loss. Once thermal balance was restored, daily energy production increased by about 10%-15%. Because the cooling system operated only when necessary, water consumption remained efficient (approximately 250-300 mL per day), with short sprays (~10 s) triggered whenever the panel reached 35 °C. The DS18B20 sensor’s high precision (± 0.5 °C) ensured timely activation. Observations over the 3-day period confirmed smooth system operation without false alarms caused by ambient temperature fluctuations.

In hot countries such as Pakistan, panel heating is a major issue, and this low-cost cooling strategy is highly beneficial. A simple cooling system added an average of 15-18 Wh per day for a 20 W panel [Figure 8]. Applied to larger systems, this improvement can substantially enhance power output and extend panel lifespan.

Incorporating safety features further improves operational longevity and reliability. The rain protection cover, activated by a sensor, prevents water accumulation, soiling, or debris damage, maintaining optimal performance and extending panel life. The rain cover has been shown to prevent up to 10%-15% energy loss from soiling when no cover is used [Table 4]. The cooling system, by keeping panel temperature below 35 °C, reduces the risk of overheating, addressing electrical and fire hazards. Overheating accelerates material degradation and increases the risk of electrical failure in PV systems. Maintaining safe thermal limits also protects structural integrity, preventing heat-related damage to the PV module. Experimental findings confirm a 15%-18% increase in daily energy output due to the cooling system [Table 11]. These results highlight the importance of integrating safety features to improve operational performance and adoptability of solar energy systems, particularly in semi-arid urban areas with extreme weather.

Overall combine system performance

When all the advanced features were combined, the system outperformed the sum of the individual components because certain features synergized effectively. The dual-axis tracker ensured the panel remained optimally oriented toward the sun, the reflectors captured additional light that the panel would not have directly received, and the cooling system minimized thermal losses, resulting in higher energy output. Figure 10 illustrates the impact of all components on PV panel power output, and Table 12 summarizes the corresponding quantitative effects.

Figure 10. Impact of Output Power on PV Panel Performance. PV: Photovoltaic.

The combined solar system provided up to 155 Wh/day, almost 65% more electricity than the original fixed system. With these small modifications, energy output increased significantly, allowing small installations to generate more power with less hardware. Peak output power reached 21.5 W, 14 W higher than the 17.5 W expected for the baseline, an improvement of 22.8%. Such enhancements are essential to ensure reliable, high-quality power during periods of peak sunlight. While individual components increased energy yield by 15%-38%, using them together did not simply add their effects linearly. Instead, addressing multiple loss factors - including solar position, light capture efficiency, and thermal effects - improved overall system performance. The automated rain protector maintained reflector efficiency under harsh weather, and the water-cooling system only activated when the temperature exceeded the set threshold, enabling the system to cope with the city’s fluctuating temperatures and weather conditions.

The dual-axis tracking ensures panels remain perpendicular to the sun throughout the day, increasing captured sunlight by up to 40%. During sunrise and sunset, the reflectors redirect sunlight that would otherwise miss the panel, enhancing irradiance. Cooling systems prevent 0.4%-0.5% energy loss per degree above 25 °C, which is particularly valuable for monocrystalline panels. When combined, these solutions address the three main limitations of standard solar panel setups.

The results demonstrate that dual-axis tracking, reflectors, and automated protection from rain and heat significantly enhance the performance of small solar installations. Lahore, Pakistan, provides a relevant example, with abundant sunlight but extreme heat and variable weather. Integrating these features substantially increases daily energy output, improving system dependability and user benefits, as shown in Table 12. A comparison between traditional and enhanced solar systems is illustrated in Figure 11.

Figure 11. Comparison of Traditional Solar System with Innovative Solar System.

The automation of the system - including solar tracking, rain protection, and cooling mechanisms -demonstrated strong performance under real testing conditions. The LDR-based solar tracking system kept the panel aligned with the sun throughout the day, contributing to significant energy gains. The rain sensor triggered the rain protection cover during light rain, preventing soiling and maintaining efficiency. The temperature control system responded promptly to overheating, keeping the panel surface within the optimal range and minimizing energy loss. Overall, the automation enhanced the system’s performance, ensuring high efficiency even under fluctuating environmental conditions.