Recent Advancement on Photovoltaic Panel Cooling Using Various Methods: A Review

1. Introduction

Solar thermal collectors and photovoltaic panels are considered advantageous for capturing and converting solar energy into usable energy because of the plentiful and limitless nature of the solar resource [1]. The photovoltaic module converts a portion of sunlight into electrical energy due to the photoconversion effect. Approximately 80% of the solar radiation absorbed by the photovoltaic panel is not converted, leading to an increase in operating temperature, resulting in decreased efficiency and aging [1]. Uncooled panel has shown to perform less efficiently with an average electrical efficiency of 9.15%, while the cooled panel had an average efficiency of 10.40% [2]. This demonstrates the evident advantages of active cooling in improving the performance of solar panels. PV cells operating in intense sunshine and high temperatures, such as in tropical or desert areas or during summer in temperate zones, typically experience greater efficiency reduction [3]. For every 1 °C increase in surface temperature of the PV module, there is a 0.5% decrease in efficiency [4]. In addition to the various benefits of PV technology, this kind of conversion system is susceptible to issues like hail, dust, and surface operating temperature, which can reduce its efficiency [5]. Thus, not all solar energy collected by photovoltaic cells is transformed into electrical energy due to the temperature increase. The excess solar energy is transformed into heat to comply with the law of conservation of energy. This squandered heat results in a decrease in the total conversion efficiency. Enhancements in efficiency are necessary for solar energy conversion technologies to become a practical renewable energy alternative. In order to create a feasible solution, it is necessary to explore several methods to address the temperature issue, leading to an enhancement in the overall effectiveness of conversion. Researchers are exploring various cooling methods to improve the efficiency and cost-effectiveness of photovoltaic panels, aiming to capitalize on the benefits of enhanced energy efficiency, cost reduction, and environmental preservation associated with advancements in photovoltaic cell performance. This increase in attention has created [6]. In the future, it will be crucial to have in-depth review papers that summarize contemporary cooling solutions to push this topic further. Some studies have concentrated on certain methodologies, as the research conducted by Ali [7] regarding phase change materials, Suresh et al., [8] regarding nanofluids as coolants, Bhakre et al., [9] discussed water cooling. Preet [10] about water and PCM cooling, Othman et al., [11] regarding air conditioning, Kane et al., [12] conducted research on thermoelectric cooling, while Elbreki et al., [13] also contributed to the field on photovoltaic cooling using passive cooling. Bahaidarah et al., [14] discussed uniform cooling, while Siah Chehreh Ghadikolaei [15] provided a detailed analysis of cooling methods, excluding thermoelectric and evaporative cooling methods.

This paper aims to offer a thorough and current examination of modern cooling methods for solar systems, emphasizing their crucial role in enhancing both the sustainability and effectiveness of these systems. The inquiry delves into many views and categorizations of sophisticated cooling methods, such as heat exchangers, nanofluids, and phase change materials.

2. Methodology

This section will explain the operational principle of various technologies that can mitigate the impact of increased temperature on a PV panel operating above the recommended temperature of the Standard Test Conditions (STC). The technical explanation aims to facilitate the understanding of relevant research findings from various authors.

2.1. Photovoltaic Panel Cooling Using Heat Exchanger

A closed-loop system is typically used to establish a cooling system for photovoltaic panels with a heat exchanger. This entails connecting a network of cooling pipes or tubes directly to the rear of the PV panels, through which a cooling fluid, typically water or a glycol mixture, flows. The heat exchanger is incorporated into this circuit. The solar panels capture heat from sun and transfer it to the fluid flowing through the pipes. Next, the warm fluid is directed to the heat exchanger, where it is cooled through heat exchange with the surrounding environment or another cooling medium. The fluid returns to the panels after cooling to absorb more heat, thus maintaining the temperature of the solar panels and improving their efficiency. This technology not only maintains ideal operating conditions for solar panels but also uses the gathered heat for additional purposes like heating water or spaces, enhancing total energy efficiency. Figure 1 and 2 shows the experimental setup and schematic diagram of photovoltaic panel cooling using heat exchanger [16].

Nasir et al., [17] conducted an experiment centered around a model of water cooling pipework on the backside of the PV panel. Copper pipes with a high thermal conductivity of approximately 385 W/m-K, were formed into elliptical shapes as in Figure 3 and attached to the backs of PV panels to serve as heat exchangers. The benefit of using a particular elliptical copper pipe cooling model is that it reduces the temperature gradient across the panel. The schematic diagram of the setup and the experimental setup is shown in Figure 4 and Figure 5 respectively.

Jakhar et al., [18] created an experimental configuration for a PV/T system connected to a ground-coupled heat exchanger(GCHE) in Pilani, Rajasthan, India. This configuration was utilized for trials to assess the system’s performance. The schematic setup is showed in Figure 6. The front cross-section view of the PV/T panel is shown in Figure 7.

The prototype system was created with a mono-crystalline silicon photovoltaic panel, an artificial solar system, a repository, and a data gathering system. The PV panel had a total size of 780 square millimeters and had 72 cells. The setup consisted of a solar simulator with metal halide lamps, a thermometer, 12 K-type thermocouples, an electrical load for recording voltage and I-V data, a container for liquid PCM underneath the PV panel, and a finned copper-tube heat exchanger [19]. Figure 8 displays a schematic design of the setup, including a mono-crystalline silicon photovoltaic panel, artificial solar system, repository, and data attainment system [19].

The photovoltaic panel had an inclination angle of 18°, and cold water was introduced through the bottom entrance of the heat exchanger. Designated amounts of PCM were introduced into the container, and the cooling water flow rate was adjusted correspondingly. Temperature was measured at 12 specific locations on the surface of the PV panel, in addition to collecting voltage and I-V data [19]. Each PV panel matrix has an effective area of 30 mm x 26 mm and contains 72 well-functioning cells as shown in Figure 9.

Fabbri & Greppi [20] undertook a study to create a numerical model for simulating the performance of an integrated photovoltaic-thermoelectric (PV-TE) module. The model is finite and steady-state, created to numerically replicate the module’s performance under specific conditions.

An new cooling approach is suggested in Figure 10, which simplifies solar cell cooling and thermoelectric conversion technology by combining the heat exchanger with the thermoelectric converter, utilizing the Seebeck effect. The heat exchanger also serves as a structural support for the cells [20].

An experimental evaluation of a photovoltaic thermal (PVT) system, supplemented by an underground heat exchanger (UHE), is conducted in Baghdad, Iraq during tough summer weather conditions [21]. This setup intends to evaluate the practicality and effectiveness of utilizing an underground heat exchanger to cool a PVT system, perhaps enhancing its electricity output in areas with severe weather conditions [21]. A 3U-shaped copper tube heat exchanger, 22.25 meters long and with strong thermal conductivity, was buried 4 meters deep. The depth was selected after initial research showed consistent ground temperatures that are suitable for effective heat dispersion. Figure 11 shows the area where the experiment was conducted, the heat exchanger which was used and how the thermocouple was distributed on the Underground Heat Exchanger (UHE).

Two monocrystalline PV modules were utilized, one operating as a conventional PV system and the other enhanced with a spiral heat exchanger on the rear side. The panels were tilted at a 33° angle facing south [21]. Thermocouples were used to monitor the temperatures at the entrance and output of the heat exchanger, while a water pump regulated the flow rate of the cooling water through the system [21].

The study proposed by Saftoiu & Morega [22] a dual cooling technique for photovoltaic (PV) panels to improve efficiency by lowering operating temperatures, which can negatively impact performance. The technology included a water-circulated counter-current heat exchanger and a unique pulsed fluid cooling system, both located on the back of the panel. The counter-current heat exchanger efficiently distributed cooling fluid over the panel to constantly remove heat, while the pulsed cooling system injected cooling fluid periodically to manage peak thermal demands dynamically. Numerical simulations were used to model these systems to evaluate their capacity to reduce temperatures and improve the electrical efficiency of the PV panel. The models quantified the enhancements in temperature regulation and the possible reuse of captured thermal energy in secondary energy conversion cycles, enhancing overall energy management [22]. This system has counter-current flow pipes on the rear face of the PV, as seen in Figure 12.

The study implemented an innovative cooling system for photovoltaic (PV) panels to enhance energy efficiency by integrating a minichannel cooler and a geothermal system [23]. In this methodology, PV cells were directly bonded to a polymer minichannel heat exchanger during panel fabrication, using Ethylene Vinyl Acetate (EVA) as an adhesive, which minimizes thermal contact resistance. The heat exchanger, designed with minichannels to increase the surface area for effective heat transfer, facilitated the removal of heat from the PV cells. This extracted heat was then dissipated using a geothermal cooling system, where coolant circulated through underground plastic pipes leveraged the stable subterranean temperatures as a natural cooling medium. Temperature measurements were conducted with thermocouples and thermal imaging to assess the efficacy of this cooling approach in maintaining optimal PV cell temperatures, thereby enhancing their electrical output and efficiency. Additionally, an economic analysis was performed to evaluate the cost-effectiveness of the system by comparing the levelized cost of energy (LCOE) with conventional cooling methods [23].

Photovoltaic cells in modern PV panels are attached to tempered glass using EVA glue. EVA additionally bonds the cells to Tedlar backsheet for environmental protection. The materials are stacked in layers and crushed using a vacuum, then assembled in around 15 minutes at a temperature of around 140 degrees Celsius. In our model, the fabrication process remains the same, with the only alteration being the attachment of the cooler directly behind the photovoltaic solar cell using EVA, as seen in Figure 13.

The panel linked to a geothermal cooling system includes plastic pipes buried underneath. To minimize installation costs and space requirements, the geothermal heat exchanger is designed in a coil shape, which is the standard configuration for sale [23]. Figure 14 depicts the schematic diagram of the system.

The study performed a numerical analysis to enhance the efficiency of photovoltaic (PV) panels by using cooling techniques, particularly for panels integrated into vented facades of structures using TRNSYS computer software [24]. The emphasis was on optimizing the fixed location of the panels and improving their conversion efficiency through temperature control. The proposed cooling method entailed attaching water heat exchangers to the rear of the PV panels. Figure 15 displays the numerical model.

The study by Siddiqui et al., [25] describes a detailed analysis and practical assessment of an innovative heat exchanger design intended for cooling photovoltaic (PV) panels. The approach combines computational fluid dynamics (CFD) modelling with experimental particle image velocimetry (PIV) to enhance and evaluate different heat exchanger designs. The CFD model initially evaluated the effects of several design factors, including channel counts, manifold width, and the position and form of inlet/exit ports. Fourteen designs were created to maximize the top surface temperature, temperature uniformity, and heat transfer efficiency in relation to pumping power. The top-performing designs were built and tested using Particle Image Velocimetry (PIV) to assess flow dispersion and confirm the accuracy of the Computational Fluid Dynamics (CFD) model predictions. Variety of design are selected for optimization as shown in Figure 16.

The summary of cooling PV panels using heat exchanger is illustrated in Table 1.

2.2. Photovoltaic Panel Cooling Using Nanofluid

Nanofluid is used to improve the heat transfer qualities of the cooling fluid in photovoltaic panels by adding nanoparticles to a base fluid such as water or glycol. Nanofluids consist of particles usually composed of metals or metal oxides like copper, aluminum, or titanium dioxide, and have enhanced thermal conductivity and heat transfer properties in comparison to conventional fluids. Nanofluids, when passed via a cooling system connected to PV panels, effectively absorb and remove heat from the panels because of their improved thermal characteristics. This leads to a decrease in the surface temperature of the PV panels, which helps to maintain or maybe enhance their electrical output efficiency. Utilizing nanofluids for cooling PV panels is an innovative method that leverages nanotechnology to mitigate the decrease in efficiency that solar panels face in high temperature environments. Figure 17 shows the procedure to prepare nanofluid.

The configuration had a single-crystal PV panel with a spiral tube collector connected to its rear side. The setup enabled the nanofluid to pass through the collector, extracting surplus heat from the PV panel. A comparison was made between the performance of this setup, a standalone PV panel as shown in Figure 18, and a PV/T system that was cooled using only water as shown in Figure 19 [29].

Qeays et al., [30] conducted a study with the configuration comprises a 300W polycrystalline silicon photovoltaic module with copper tubes positioned beneath the PV cells for cooling. Nanofluid flows through the tubes to lower the surface temperature of the PV system. A counterflow shell-and-tube heat exchanger design is used to cool the nanofluid after heating. Temperatures are gauged with K-type thermocouples and an infrared thermometer. The electrical circuit consists of charge controllers, storage batteries, and a DC load to maintain uninterrupted electricity generation [30]. The schematic diagram of the experimental setup is shown in Figure 20.

Bayoumi et al., [31] uses Comsol Multiphysics software, a Finite Element Method (FEM), and Matlab for simulations, specifically concentrating on an electro-thermal model of the PV panel. A PV/T system model is developed to investigate the impact of various back pipe configurations installed beneath the PV module. The structures consist of a serpentine shape and a newly suggested square shape, selected for their ability to enhance the efficiency of heat transfer and the efficiency of conversion as shown in Figure 21.

Khalili et al., [32] integrated a thermoelectric generator (TEG) layer with traditional layers of photovoltaic-thermal (PVT) modules to make use of waste heat and enhance efficiency. The PVT-TEG unit utilized a cooling duct at its base to lower the cell temperature, with the choice of fluid and duct design influencing system efficiency. The combination layer of PVT and TEG is shown in Figure 22.

Three distinct duct shapes (circular, rhombus, and elliptic) were examined as shown in Figure 23 [32].

A numerical simulation technique was used in a research that investigated the cooling of a photovoltaic (PV) solar panel with Al₂O₃-water nanofluid [33]. The technique focused on using the finite element method (FEM) to solve the Navier-Stokes and energy conservation equations that control the fluid dynamics and heat transfer processes between the solar panel and the nanofluid. Figure 24 displays the arrangement utilized in this investigation.

The work by Shahad et al.,[34] utilized experimental and theoretical methods to examine the effects of employing SiC/Water nanofluid as a coolant on the efficiency of photovoltaic/thermal (PV/T) panel systems. The experimental setup had monocrystalline PV panels that were altered to include a cooling system constructed from 3mm thick aluminium, which was affixed to the back of the panels. A theoretical model of this configuration was created in SolidWorks and analyzed using ANSYS 18.2 to forecast the system’s performance under different circumstances [34].

Three identical monocrystalline photovoltaic modules were built and deployed at Babylon University campus in Iraq (32.46 °N, 44.42°E). Two of the PV modules were altered to include a pocket aluminium collector, one cooled with SiC/Water nanofluid and the other with pure water. The third PV module’s back sheet was cooled by the surrounding air, as seen in Figure 25. The nanofluid was pumped and cooled using a helical heat exchanger, as seen in Figure 26. The tilt angle was modified monthly based on the inclination angle, while the PV modules were oriented towards the south (zero azimuth angle). Figure 26 and Figure 27 display the schematics of the rig.

There are a total of 12 thermocouples placed evenly throughout each photovoltaic cell surface to detect temperature. Two fabricated heat exchangers made of straight metal rectangular tubes are utilized to cool the PV cells. The design has 23 parallel channels made of aluminium with measurements of 24.5 cm in length, 5 mm in width, and 3.5 mm in depth. All channels have the same rectangular entry cross-section, as seen in Figure 28 [35].

Figure 29 and Figure 30 display the setup and schematic diagram of the entire experimental equipment. PV cells 1 and 2 in the experimental setup are cooled using nanofluids and water, respectively, with the help of two circulating centrifugal pumps. The third photovoltaic cell operates without cooling [35].

The summary of cooling PV panels using nanofluid is illustrated in Table 2.

2.3. Photovoltaic Panel Using Phase Change Material

Phase change materials (PCMs) provide a passive and effective thermal management solution when used to cool photovoltaic (PV) panels. Phase change materials (PCMs) are incorporated within the solar panel system, often positioned behind the panels to efficiently capture surplus heat. These materials experience a phase transition at precise temperatures, transitioning between solid and liquid states, and absorb or release significant amounts of heat in the process. The phase change material absorbs heat as it melts, which keeps the solar panels at a lower and more consistent temperature. This process optimizes their efficiency by reducing the performance decline usually caused by high temperatures. As temperatures decrease, the phase change material solidifies, releasing the stored heat and getting ready for the next cycle, thus maintaining the system’s efficiency without requiring external energy inputs.

Figure 31 displays the schematic representation drawn in SolidWorks of the implementation of PCM in cooling photovoltaic panel [39].

The phase change material was placed in an 80°C water bath to progressively melt the salt hydrate. Subsequently, the melted PCM was poured into the container as shown in Figure 32(a). The heat exchanger component was affixed to the container to seal it from the air’s harmful impact on the PCM. Figure 32(b) displays the completed arrangement, positioned on the 30-degree angle mounting framework, aligned with the longitude of Tehran city [39].

Figure 33 displays the electrical circuit used to measure the maximum power output of the PV/T device [39].

Kiwan et al., [40] conducted a study involving both theoretical modelling and experimental setup. The researchers utilized mathematical formulations based on thermal resistance and energy balance concepts to predict the performance of PV systems with and without PCM cooling. Two identical PV panels were deployed outdoors for empirical testing, one with PCM attached to its back and the other without PCM for comparison. The PCM used was paraffin graphite panels, known for good thermal conductivity, covered with an aluminium sheet to enhance heat dissipation [40].

The experimental system included solar photovoltaic panels, an inverter, a control unit, and batteries as shown in Figure 34.

This study used Ansys Fluent software to conduct unsteady numerical simulations. It utilized a two-dimensional simplified geometry for both the regular PV module and the PV module integrated with PCM (PV-PCM) [41]. Two different types of PCM was used in this study which are Rubitherm 28 HC (PV-PCM_RT28) and Rubitherm 35 HC (PV-PCM_RT35) both has melting point of 27 to 29°C and 34 to 36°C respectively [41]. The PV-PCM modules are made of five different layers which are glass glass cover, PV cells, two EVA sheet (EVA-PV-EVA), Tedlar, PCM material and another two plates of PCM tank as shown in Figure 35.

The study conducted by Badi et al., [42] focused on improving the effectiveness of solar panels by utilizing a phase change material (PCM-OM37P) to regulate panel temperatures close to ambient values. The study was place at the Renewable Energy and Energy Efficiency Center (REEEC) at the University of Tabuk. Three identical solar systems, totalling 9 kW in capacity, were monitored from a remote location. PCM packs were affixed to the rear of the solar panels to collect surplus heat throughout the day, then releasing it later to lower the working temperature of the panels and enhance their efficiency [42]. The University of Tabuk Renewable Energy and Energy Efficiency Center (REEEC) showcased improved photovoltaic efficiency on three identical solar systems at their location, each with a capacity of 3kW, totalling 9kW. Refer to Figure 36 for further details.

Approximately 60 BioPCM packs, each measuring 128 x 153mm and weighing 150g, were attached to the rear of the PV panel using a both sides thermal conductive and strong acrylic glue. The packs are constructed of fiberglass with conductive ceramic powder form, as seen in Figure 37.

The study conducted by Rajaee et al., [43] improved the performance of a photovoltaic/thermoelectric generator (PV/TEG) hybrid system by experimentally utilizing cobalt oxide nanofluid and phase change material (PCM) as cooling agents. Figure 38 displays the design of the experimental setup and the PV/TEG configuration. The photovoltaic panel absorbs solar irradiance.

Five k-type thermocouple sensors were used in this configuration to measure various temperatures. The initial sensor was positioned on the external surface of the photovoltaic (PV) system to monitor the temperature of the PV cell’s surface. The second sensor was placed at the rear of the photovoltaic cell. The third sensor was connected to the cool side of the Thermoelectric Generator (TEG). The remaining sensors recorded the temperatures of the input and output fluids, allowing for a straightforward calculation of the heat absorbed by the coolant fluid. A tiny pump with little power consumption was used to circulate the cooling liquid in the integrated system. Moreover, all components were connected to each other using heat conductive paste. Figure 39 shows the snapshot of the experimental setup [43].

The experimental study concentrated on implementing several cooling methods for photovoltaic (PV) panels to enhance their efficiency and power generation [44]. The approaches examined involved the utilization of phase change material (PCM), thermoelectric modules (TEM), and aluminum fins. Figure 40 displays an overall perspective of the experimental arrangement [44].

The study monitored the surface temperatures of the solar panels and outside temperatures using a 0.51 mm diameter T-type thermocouple from OMEGA. Ten thermocouples were utilized in the studies, and their positions are illustrated in Figure 42 [44].

Figure 41. Displays the arrangement of the thermocouples on the photovoltaic panels.

Figure 41. Displays the arrangement of the thermocouples on the photovoltaic panels.

The study’s approach included an experimental setup using two similar 20 Wp polycrystalline PV modules, one containing Phase Change Material (PCM) and one without [45]. The PCM utilized was OM29, a commercial organic substance placed directly on the back of the PV module to improve heat transmission by removing the conduction barrier caused by an intermediary layer. The back of the PCM was covered with a composite material of tin and aluminum to avoid leaks during the phase transition [45].

Two identical 20 Wp polycrystalline PV modules from Loom solar, measuring 450 mm × 350 mm × 22 mm, were utilized in the experiment. One module was employed for PV without PCM, and the other for PV with PCM, as seen in Figure 42. 2.8 kilos of liquid OM29 PCM was put on the backside of the PV module with 5% room reserved for volume change during phase transition or expansion. The rear side of the PCM was sealed using a 0.5-mm tin coupled with an aluminium sheet to prevent leakages during phase transition [45].

Figure 42. Experimental configurations for photovoltaic panel with and without PCM utilizing OM29.

Figure 42. Experimental configurations for photovoltaic panel with and without PCM utilizing OM29.

The study by Jamil et al., [46] utilized a technique that includes an experimental setup to assess the performance improvements resulting from adding nano phase change materials (nano-PCMs) in solar panels under different situations. The trials was place outside at the University of Engineering and Technology in Taxila, Pakistan. Three distinct nano-PCMs were created by combining multiwall carbon nanotubes, graphene nanoplatelets, and magnesium oxide nanoparticles with a phase change material known as PT-58. Nano-PCMs were used on solar panels at concentrations of 0.25 wt% and 0.5 wt%. The PV panels with nano-PCMs were compared to traditional PV panels lacking nano-PCMs. The measurements were concentrated on metrics like temperature reduction and increase of electrical efficiency. Figure 43 shows the present experimental setup for the study endeavor [46].

The experimental setup primarily included four PV modules, a Data Acquisition System (34972A, Agilent, USA), and a Solar Module Analyzer (PROVA 210). Figure 44 displays the schematic depiction of the experimental setup [46].

The study used a 1-D thermal resistance model in MATLAB to evaluate the performance of photovoltaic-phase change material (PV-PCM) systems over the course of a year [47]. The model utilized an improved conductivity approach to estimate convective heat transfer effects without the need to solve intricate Navier-Stokes equations, enabling rapid and expedited simulations ideal for prolonged investigation. Various phase change materials (PCMs) with different melting temperatures were assessed in five unique PV-PCM system setups. The simulations utilized actual meteorological data from Shanghai in 2017 to evaluate how variations in electrical efficiency across the seasons and year are influenced by variances in PCM characteristics and environmental conditions. The method enabled a thorough examination of how PCM properties, weather fluctuations, and solar system efficiency interacted across a whole year [47].

Figure 45 displays the setup of the PV-PCM system. The PV panel is divided into five layers: glass, EVA, PV cells, and TPT, for illustrative purposes. The photovoltaic panel is in direct contact with phase change material (PCM) enclosed in a chamber made of polypropylene (PP) plates [47].

Figure 46 displays the experimental design. The PV panel is linked to a battery and a dump load to facilitate the transmission and consumption of the generated power. An MPPT controller is integrated into the electrical system to ensure the PV system consistently functions at its peak power point. The PV temperature and PCM temperature are measured using PT-100 temperature sensors [47].

The summary of cooling PV panels using nanofluid is illustrated in Table 3.

3. Economical Advantages

Closed-loop pulsing heat pipe (CLPHP) for the purpose of cooling photovoltaic (PV) panels offers significant cost benefits. The CLPHP-based cooling system offers a more cost-effective solution for operation and maintenance as compared to conventional water-based flat plate cooling systems. The absence of energy-consuming components such as pumps or fans, which are essential for conventional active cooling techniques, is the reason behind the energy efficiency of the CLPHP system [52]. The payback period of the investment calculated shows that water-based cooling method has better cooling but with longer payback period which is 14.5 years compared to active CLHP cooling which is 13 years [52].

An average payback period for uncooled PV panel ranges around 1.9 years according to Figure 47 [53]. The more complex the cooling element the better the efficiency of the panel. The benefits of superior cooling far outweighs the cost due to longer lifespan of the panel.

The water-based cooling systems demonstrated the highest energy production, with an average of 32.29 kWh, resulting in cost savings of around USD 0.273. Thermoelectric cooling has proven to be the most efficient method, with an average energy output of 34.512 kWh and resulting in the greatest cost reduction. This is especially notable in the month of July, where the average cost savings amounted to USD 0.473 [53].

A water cooled system using rainwater alone shows capital expenditure for the water cooling system is roughly EUR 750 for a 5 kWp photovoltaic (PV) plant and EUR 1200 for a 10 kWp installation. The expenses encompass the necessary components for the system, such as the header, water tank, water pump, cooler, pipelines, filter, controller, and other fittings [54]. Based on the experimental results of the study, the water cooling system is projected to enhance the energy production of the PV panels by around 10%. For a standard 5 kWp installation, this results in an extra 500 kWh per year, whereas a 10 kWp installation might generate an additional 1000 kWh yearly.

4. Conclusion

The review thoroughly examined different cutting-edge cooling solutions designed to improve the effectiveness and lifespan of photovoltaic (PV) panels. Various methods, such as using nanofluids, heat exchangers, and phase change materials (PCMs), have demonstrated significant potential in lowering the operating temperatures of PV panels. Each cooling method has distinct advantages and difficulties, underscoring the need of choosing the right approach according to certain environmental factors and system needs.

Nanofluids have shown great promise in increasing heat transfer rates because of their improved thermal conductivity and heat capacity. Nanoparticles like as copper oxide and titanium dioxide, when added to conventional coolants, have been shown to effectively reduce the surface temperature of PV panels, hence alleviating efficiency losses due to overheating. Heat exchangers, including passive and active systems, are effective in preserving the operational efficiency of PV systems by removing excess heat and preventing performance degradation.

Phase change materials (PCMs) are a significant improvement in cooling photovoltaic (PV) panels. Phase change materials (PCMs) help regulate the temperature of PV panels by absorbing heat during melting and releasing it during solidification, which improves their efficiency and stability. Integrating phase change materials (PCMs) effectively regulates thermal conditions and promotes a more sustainable energy system by decreasing the need for energy-consuming active cooling components.

Enhancing PV panel efficiency with innovative cooling technology is crucial for increasing the use of solar energy. By persisting in innovating and enhancing these cooling techniques, we may greatly improve the feasibility and durability of solar power as a substantial component of the worldwide energy supply. This analysis emphasizes the significance of focused research and development initiatives that correspond with the changing requirements of the energy industry, ultimately aiding in creating a cleaner and more sustainable future.