Design and Simulation of a Cooling System for FTO/I-SnO<sub>2</sub>/CdS/CdTe/Cu<sub>2</sub>O Solar Cells

Khaledi, Parinaz; Behboodnia, Mahdi

doi:https://doi.org/10.1155/2023/1718588

International Journal of Photoenergy

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Abstract Introduction Conclusion Data Availability Conflicts of Interest Acknowledgments References Copyright Related Articles

Research Article | Open Access

Volume 2023 | Article ID 1718588 | https://doi.org/10.1155/2023/1718588

Design and Simulation of a Cooling System for FTO/I-SnO₂/CdS/CdTe/Cu₂O Solar Cells

Parinaz Khaledi¹and Mahdi Behboodnia¹

Academic Editor: Qiliang Wang

Received28 Jun 2022

Revised22 Feb 2023

Accepted03 Apr 2023

Published20 Apr 2023

Abstract

The temperature in solar cells is one of the main factors affecting their efficiency. Increasing the temperature in solar cells reduces efficiency. According to previously published and recently published studies by our team, with increasing temperature in 5-layer FTO/i-SnO2/CdS/CdTe/Cu2O solar cells, the efficiency has decreased by 8.86% per 100 K. In this research, phase change materials have been used to control the temperature in 5-layer solar cells. Our overall goal in this study is to control the temperature in FTO/i-SnO2/CdS/CdTe/Cu2O solar cells to increase their efficiency. The results obtained using simulations and numerical analysis and comparative analysis show that if one layer is used as a cooling arrangement in 5-layer FTO/i-SnO2/CdS/CdTe/Cu2O solar cells, it reduces the surface temperature of solar cells and increases efficiency.

1. Introduction

One of the weaknesses of photovoltaic systems, especially solar cells, which was also mentioned in previous studies [1] is that with increasing the temperature of solar panels, the maximum output power decreases linearly [1–3]. Due to the increase in temperature, not all of the solar energy absorbed by the photovoltaic cells is converted into electrical energy. To satisfy the law of conservation or survival of energy, the remaining solar energy is converted to heat. Finally, the heat generated on the surface of the panel or module reduces the overall conversion efficiency. Solar cells, depending on their type, convert 4 to 17% of common solar energy into electrical energy. In other words, more than 50% of solar energy is converted to heat instead of electricity [4]. The operating temperature of solar cells in hot seasons reaches more than 338.15 K, so a reduction of 14-22% efficiency will be obvious. Increasing the temperature by more than 298.15 K reduces the efficiency by 0.3 to 0.5% per Kelvin [5–8]. To improve the use of these modules, it is necessary to increase efficiency and reduce costs. Both performance improvements and longevity improvements are important issues for further cost reductions. For this purpose, it is necessary to provide different solutions to solve the temperature problem in solar cells. The study of solar cell simulations is very useful for predicting the output performance of solar cells before the actual construction of the cell and will significantly reduce production costs and avoid excessive costs. Various tools for simulating solar cells are available, including wxAMPS, a 1D solar cell simulation program, Silvaco ATLAS software, SCAPS-1D software [1], GPVDM software, and more. So far, a lot of research has been done and published by these simulation tools [1]. We first did the programming in Maple software, then we did the same again in MATLAB due to the high speed of MATLAB, and checking the accuracy of programming as well as comparison of the results. In our previous work [1], we simulated and studied the structure of a 5-layer solar cell consisting of FTO/i-SnO₂/CdS/CdTe/Cu₂O layers and concluded that lowering the temperature could increase the efficiency of this 5-layer structure. But we did not discuss the method of cooling in this structure. So far, various technologies for cooling the operating surface of 5-layer solar panels with FTO/i-SnO₂/CdS/CdTe/Cu₂O structure in order to increase the efficiency of the entire conversion system have not been studied by researchers. Therefore, studying and selecting a suitable cooling method for this 5-layer structure is essential to improve production efficiency and long-term reliability. There are several cooling methods. Choosing the right cooling method can improve electrical efficiency and reduce cell degradation over time, thus maximizing the lifespan of solar cells. The most important cooling methods are active/inactive heat pipe [9–11], natural/forced air flow [12–14], forced water flow [15–18], concentrator photovoltaics-thermal, photovoltaic-thermal [19], phase change material [20–23], immersion in water[24], disable heatsink, microchannel (active heatsink) [25–27], transparent coating (photon crystal cooling) [28], and thermoelectric module [29]. Our aim in this article is to investigate two of the most important factors affecting the efficiency of cadmium telluride solar cells, which have not been studied in previous works and have not been mentioned in most studies. Important parameters that we will examine in this study are the study of the effect of cooling and the change of radiation angle in 5-layer cadmium telluride solar cells with FTO/i-SnO₂/CdS/CdTe/Cu₂O structure. In the present study, the cooling of cadmium telluride solar cells with 5-layer structure FTO/i-SnO₂/CdS/CdTe/Cu₂O was simulated by phase change materials.

2. General Steps of Conducting Research

Figure 1 summarizes the work done in this study in 5 steps.

In this research, to prevent duplication, the first and second steps of the work, i.e., a numerical study using discretization of mathematical equations and simulation of a 5-layer cadmium telluride solar cell, were cited in reference [1]. Figure 2 shows the structure of a 5-layer cadmium telluride solar cell. We considered this structure as a reference in our work.

3. Different Methods of Cooling Solar Cells

In order to increase the efficiency of cadmium telluride solar cells, we have carefully tested various technologies in the field of their cooling. The active/passive heat pipe method is very suitable due to the high initial cost and more complex construction than other models in cases where there is a need to respond to both electrical and thermal demand and the initial cost is not considered. The natural/forced air flow method is also effective only in cold weather conditions. In forced water flow and microchannel methods, the desired efficiency is not achieved due to the constant water flow, and in order to achieve the desired efficiency, the water flow must be controlled and adjusted. In the water immersion method, efficiency is greatly reduced on cloudy days. In the passive heatsink method, the efficiency decreases in hot areas and the cooling does not work well. Also, no repelled heat is used. In the transparent coating method (photon crystal cooling), heat that can be used for indoor applications is wasted. Another technique that can be used to reduce the operating temperature of the surface of cadmium telluride solar cells to achieve higher electrical efficiency is the use of phase change materials. These are concealed heat storage materials used on the back of the PV panel (Figure 3). As the panel temperature rises, the chemical bonds separate from the solid to the liquid to change phase. When the temperature of the material reaches the phase change limit with heat storage, the material begins to melt, then its temperature remains constant until the melting process is complete. This material is called latent heat storage because heat is stored during the melting process (phase change process). The cooling effect of the phase change material is acceptable and the overall efficiency increases. It is able to store large amounts of heat with low-temperature changes. Phase change occurs at a constant temperature, and the stored heat can be used to heat buildings. Therefore, phase change materials can be a good solution for cooling cadmium telluride solar panels. These substances are divided into three categories: organic (paraffin and fatty acids), inorganic (hydrated salts), and molten (organic and inorganic). Due to the high ability of phase change materials to absorb heat, these materials have quickly been proposed as a factor for the free cooling of various devices. In recent years, many studies have been conducted on the application of phase change materials in controlling the temperature of solar cells. By comparing the performance of a simple solar cell with a solar cell equipped with phase change materials in a laboratory, a group of researchers showed that adding phase change materials to solar cells reduced the panel temperature by 278.15 K and increased the panel efficiency by as much until it becomes 3.1% [30]. Another group examined the effect of phase change materials on concentrating and decentralized solar cells in 2015. They found that adding phase change materials to concentrating solar cells could reduce panel temperatures by 278,349 K. They also reported that phase change materials increase the efficiency of concentrating solar cells by 15.9% and decentralized (normal) solar cells by 10% [31]. In the references [32, 33], the researchers compared a thermal solar cell with a solar thermal cell with water pipes behind which passed through the phase change material. They showed that when the phase change material backed the solar panel added, the water passing through the phase change material is approximately 279.15 K higher than when there is no phase change material. They report that the addition of phase change material in the photovoltaic panels creates this potential in solar cells to make hot water available over a longer period of time. In the reference [16], simple thermal cells used on the roof of the building are modeled and the effect of phase change materials on the efficiency of solar panels is investigated. They reported that the addition of phase change materials on the efficiency of thermal solar cells increases by 8.1% and simple solar cells by 4.2%. In the reference [34], by simulating in Transis software, they compared the performance of conventional photovoltaic panels and photovoltaic panels equipped with phase change materials. They reported that the temperature of solar cells equipped with phase change materials was 308.15 K lower than that of solar cells without phase change materials. In the reference [35], phase change materials were used in a multipurpose hybrid system in the building. The researchers reported in references [36, 37] that the use of phase change materials for underfloor heating could reduce costs by up to 20%.

4. Simulate the New System

Our new system consists of a 5-layer cadmium telluride solar cell in which a layer of calcium hexahydrate is simulated as a phase change material to improve the performance of solar cells at its dorsal junction. The structure of this system is shown in Figure 3.

5. Properties of PCM Layer

In this study, calcium hexahydrate was used as the primary PCM. Calcium chloride hexahydrate PCM is far cheaper than other kinds of phase change material, have high latent heat, and have suitable properties. Calcium chloride hexahydrate, as Table 1 presents, melts at 29.6C which can assure the melting of the material when absorbing the excess heat from solar radiation and it freezes at 20°C. Furthermore, compared to paraffinic PCMs, calcium hexahydrate has higher thermal conductivity (at least four times) which is a very crucial parameter for the heat transfer process. Table 1 lists the thermophysical properties of calcium chloride hexahydrate.

6. Comparison of CdTe Solar Cells with and without Phase Change Material (PCM)

Figure 4 shows the graph of open circuit voltage in terms of time for 5-layer cadmium telluride solar cells with FTO/i-SnO2/CdS/CdTe/Cu2O structure, assuming a radiation intensity of 1000 W/m² in the case with red phase change material. And it is shown in blue color without phase change material. According to Figure 4, by adding a layer as a phase change material to the back junction of the solar panel, the voltage increases compared to solar cells without phase change material, which exactly matches the results of the previous work [38, 39] and proves the correctness of our work.

Figure 5 shows the short-circuit current density graph in terms of time for 5-layer cadmium telluride solar cells with FTO/i-SnO2/CdS/CdTe/Cu2O structure, assuming a radiation intensity of 1000 W/m² in the case of color phase change material. It shows red and no phase change material in blue color. By adding a phase change material layer to the back junction of the solar panel, the short-circuit current density is increased compared to solar cells without phase change material, which is in close agreement with the results of previous work [38, 39] and proves the correctness of our work.

Figure 6 shows the graph of the filling factor in terms of time for 5-layer cadmium telluride solar cells with the structure of FTO/i-SnO2/CdS/CdTe/Cu2O, assuming a radiation intensity of 1000 W/m² in the case with red phase change material. And it shows blue color without phase change material. By adding a layer as a phase change material to the back junction of the solar panel, the fill factor increases compared to solar cells without phase change material, which exactly matches the results of previous work [38, 39] and proves the correctness of our work.

Figure 7 shows the graph of efficiency in terms of time for 5-layer cadmium telluride solar cells with FTO/i-SnO2/CdS/CdTe/Cu2O structure, assuming the radiation intensity of 1000 W/m² in the state with red phase change material and without the phase change material shown in blue color. By adding a layer as a phase change material to the back junction of the solar panel, the efficiency is increased compared to solar cells without phase change material, which exactly matches the results of previous work [38, 39] and proves the correctness of our work. As can be seen from Figure 7, the addition of the PCM layer prevents the reduction of 4.48 percent efficiency due to the heating of the cell surface.

The efficiency of this cell under constant radiation for 6000 seconds without phase change material reaches 20.35%, which by adding the PCM layer in this period of time, the efficiency becomes almost 24%.

We define relative efficiency as formula (1), in which the efficiency of two solar cells with the structures FTO/i-SnO₂/CdS/CdTe/Cu₂O and FTO/i-SnO₂/CdS/CdTe/Cu₂O/PCM is measured relative to each other under the same conditions.

In Equation (1), η is the efficiency and is the maximum power and PCM represents the phase change material.

7. Conclusion

One of the chief aims of this investigation was to enhance the efficiency of the electrical performance of the PV panel. To that end, CaCl2$6H2O was applied to regulate the PV surface temperature and increased power output. To clarify how and why this happens, based on the physics of photovoltaics, reverse saturation current rises up if surface temperature increases. Thus, Voc (open circuit) falls down in value which decreases the fill factor leading to a lower efficiency of the solar cells. Also, a temperature increase results in a decrease of bandgap energy that causes an increase in Jsc (short circuit) which enhances the overall efficiency. Considering the reduction of Voc and Jsc raising up, it can be concluded that the overall efficiency will decrease if surface temperature increases and vice versa. In this research, we designed and simulated a cooling system for 5-layer cadmium telluride solar cells with FTO/i-SnO2/CdS/CdTe/Cu2O structure using phase change materials. The results showed that the cooling of cadmium telluride solar cells using phase change materials has a significant effect on voltage and current and finally the power of these panels.

Data Availability

Data are available at the Department of Physics, Urmia University of Technology.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

This work was funded by the Department of Physics, Urmia University of Technology.

References

P. Khaledi, M. Behboodnia, and M. Karimi, “Simulation and optimization of temperature effect in solar cells CdTe with back connection Cu₂O,” International Journal of Optics, vol. 2022, Article ID 1207082, 10 pages, 2022.
View at: Publisher Site | Google Scholar
E. Radziemska, “The effect of temperature on the power drop in crystalline silicon solar cells,” Renewable Energy, vol. 28, no. 1, pp. 1–12, 2003.
View at: Publisher Site | Google Scholar
K. K. Dixit and I. Yadav, “Efficiency improvement of PV panel using PCM cooling technique,” in Renewable Energy Optimization, Planning and Control, pp. 159–164, Springer, Singapore, 2022.
View at: Publisher Site | Google Scholar
C. Kandilli, “Performance analysis of a novel concentrating photovoltaic combined system,” Energy Conversion and Management, vol. 67, pp. 186–196, 2013.
View at: Publisher Site | Google Scholar
P. Biwole, P. Eclache, and F. Kuznik, “Improving the performance of solar panels by the use of phase-change materials,” in World Renewable Energy Congress-Sweden; 8-13 May; 2011; Linköping; Sweden (No. 057, pp. 2953-2960), pp. 2953–2960, Linköping University Electronic Press, 2011.
View at: Google Scholar
Z. J. Weng and H. H. Yang, “Primary analysis on cooling technology of solar cells under concentrated illumination,” Energy Technology, vol. 29, no. 1, pp. 16–18, 2008.
View at: Google Scholar
A. Machniewicz, D. Knera, and D. Heim, “Effect of transition temperature on efficiency of PV/PCM panels,” Energy Procedia, vol. 78, pp. 1684–1689, 2015.
View at: Publisher Site | Google Scholar
K. Kumar, S. D. Sharma, L. Jain, and R. Al Khaimah, “Standalone photovoltaic (PV) module outdoor testing facility for UAE climate,” Tech. Rep., Submitted to CSEM-UAE innovation Centre LLC.8, 2007.
View at: Google Scholar
H. Alizadeh, M. A. Nazari, R. Ghasempour, M. B. Shafii, and A. Akbarzadeh, “Numerical analysis of photovoltaic solar panel cooling by a flat plate closed- loop pulsating heat pipe,” Solar Energy, vol. 206, pp. 455–463, 2020.
View at: Publisher Site | Google Scholar
F. Al-Amri, T. S. Maatallah, O. F. Al-Amri et al., “Innovative technique for achieving uniform temperatures across solar panels using heat pipes and liquid immersion cooling in the harsh climate in the Kingdom of Saudi Arabia,” Alexandria Engineering Journal, vol. 61, no. 2, pp. 1413–1424, 2022.
View at: Publisher Site | Google Scholar
S. Sargunanathan, A. Elango, and S. T. Mohideen, “Performance enhancement of solar photovoltaic cells using effective cooling methods: a review,” Renewable and Sustainable Energy Reviews, vol. 64, pp. 382–393, 2016.
View at: Publisher Site | Google Scholar
R. Mazón-Hernández, J. R. García-Cascales, F. Vera-García, A. S. Káiser, and B. Zamora, “Improving the electrical parameters of a photovoltaic panel by means of an induced or forced air stream,” International Journal of Photoenergy, vol. 2013, Article ID 830968, 10 pages, 2013.
View at: Publisher Site | Google Scholar
J. Siecker, K. Kusakana, and E. B. Numbi, “A review of solar photovoltaic systems cooling technologies,” Renewable and Sustainable Energy Reviews, vol. 79, pp. 192–203, 2017.
View at: Publisher Site | Google Scholar
J. K. Tonui and Y. Tripanagnostopoulos, “Improved PV/T solar collectors with heat extraction by forced or natural air circulation,” Renewable Energy, vol. 32, no. 4, pp. 623–637, 2007.
View at: Publisher Site | Google Scholar
R. Li, Y. Shi, M. Wu, S. Hong, and P. Wang, “Photovoltaic panel cooling by atmospheric water sorption-evaporation cycle,” Nature Sustainability, vol. 3, no. 8, pp. 636–643, 2020.
View at: Publisher Site | Google Scholar
K. A. Moharram, M. S. Abd-Elhady, H. A. Kandil, and H. El-Sherif, “Enhancing the performance of photovoltaic panels by water cooling,” Ain Shams Engineering Journal, vol. 4, no. 4, pp. 869–877, 2013.
View at: Publisher Site | Google Scholar
M. S. Govardhanan, G. Kumaraguruparan, M. Kameswari, R. Saravanan, M. Vivar, and K. Srithar, “Photovoltaic module with uniform water flow on top surface,” International Journal of Photoenergy, vol. 2020, Article ID 8473253, 9 pages, 2020.
View at: Publisher Site | Google Scholar
W. Luboń, G. Pełka, M. Janowski et al., “Assessing the impact of water cooling on PV modules efficiency,” Energies, vol. 13, no. 10, p. 2414, 2020.
View at: Publisher Site | Google Scholar
D. I. Lee and S. W. Baek, “Development of a heating system using CPV technology and heat pipes,” Environmental Progress & Sustainable Energy, vol. 34, no. 4, pp. 1197–1207, 2015.
View at: Publisher Site | Google Scholar
N. M. R. Fumani, F. A. Roghabadi, M. Alidaei, S. M. Sadrameli, V. Ahmadi, and F. Najafi, “Prolonged lifetime of perovskite solar cells using a moisture-blocked and temperature-controlled encapsulation system comprising a phase change material as a cooling agent,” ACS Omega, vol. 5, no. 13, pp. 7106–7114, 2020.
View at: Publisher Site | Google Scholar
N. T. J. Wei, W. J. Nan, and C. Guiping, “Experimental study of efficiency of solar panel by phase change material cooling,” IOP Conference Series: Materials Science and Engineering, vol. 217, no. 1, Article ID 012011, 2017.
View at: Google Scholar
S. S. Chandel and T. Agarwal, “Review of cooling techniques using phase change materials for enhancing efficiency of photovoltaic power systems,” Renewable and Sustainable Energy Reviews, vol. 73, pp. 1342–1351, 2017.
View at: Publisher Site | Google Scholar
J. Feng, J. Huang, Z. Ling, X. Fang, and Z. Zhang, “Performance enhancement of a photovoltaic module using phase change material nanoemulsion as a novel cooling fluid,” Solar Energy Materials and Solar Cells, vol. 225, article 111060, 2021.
View at: Publisher Site | Google Scholar
S. Mehrotra, P. Rawat, M. Debbarma, and K. Sudhakar, “Performance of a solar panel with water immersion cooling technique,” International Journal of Science, Environment and Technology, vol. 3, no. 3, pp. 1161–1172, 2014.
View at: Google Scholar
A. Radwan, S. Ookawara, and M. Ahmed, “Analysis and simulation of concentrating photovoltaic systems with a microchannel heat sink,” Solar Energy, vol. 136, pp. 35–48, 2016.
View at: Publisher Site | Google Scholar
L. Chen, D. Deng, Q. Ma, Y. Yao, and X. Xu, “Performance evaluation of high concentration photovoltaic cells cooled by microchannels heat sink with serpentine reentrant microchannels,” Applied Energy, vol. 309, article 118478, 2022.
View at: Publisher Site | Google Scholar
F. Hu, X. Yang, and W. Yan, “Thermal management of high concentrator photovoltaic system using a novel counter-flow double-layer fractal microchannel heat sink,” International Core Journal of Engineering, vol. 8, no. 4, pp. 187–203, 2022.
View at: Google Scholar
H. Yuan, C. Yang, X. Zheng et al., “Effective, angle-independent radiative cooler based on one-dimensional photonic crystal,” Optics Express, vol. 26, no. 21, pp. 27885–27893, 2018.
View at: Publisher Site | Google Scholar
D. S. Borkar, S. V. Prayagi, and J. Gotmare, “Performance evaluation of photovoltaic solar panel using thermoelectric cooling,” International Journal of Engine Research, vol. 3, no. 9, pp. 536–539, 2014.
View at: Publisher Site | Google Scholar
J. Park, T. Kim, and S. B. Leigh, “Application of a phase-change material to improve the electrical performance of vertical-building-added photovoltaics considering the annual weather conditions,” Solar Energy, vol. 105, pp. 561–574, 2014.
View at: Publisher Site | Google Scholar
S. Sharma, N. Sellami, A. Tahir, K. S. Reddy, and T. K. Mallick, “Enhancing the performance of BICPV systems using phase change materials,” in AIP Conference Proceedings, AIP Publishing LLC, 2015.
View at: Google Scholar
S. Ghafarian, H. Yousefi, and M. Yarahmadi, “Review on using of phase change material (PCM) for photovoltaic (PV) cooling,” Journal of Renewable and New Energy, vol. 7, no. 1, pp. 74–83, 2020.
View at: Google Scholar
H. Akbari, M. C. Browne, A. Ortega et al., “Efficient energy storage technologies for photovoltaic systems,” Solar Energy, vol. 192, pp. 144–168, 2019.
View at: Publisher Site | Google Scholar
U. Stritih, “Increasing the efficiency of PV panel with the use of PCM,” Renewable Energy, vol. 97, pp. 671–679, 2016.
View at: Publisher Site | Google Scholar
A. D'Alessandro, A. L. Pisello, C. Fabiani, F. Ubertini, L. F. Cabeza, and F. Cotana, “Multifunctional smart concretes with novel phase change materials: mechanical and thermo-energy investigation,” Applied Energy, vol. 212, pp. 1448–1461, 2018.
View at: Publisher Site | Google Scholar
A. El Mays, R. Ammar, M. Hawa et al., “Using phase change material in under floor heating,” Energy Procedia, vol. 119, pp. 806–811, 2017.
View at: Publisher Site | Google Scholar
K. Faraj, J. Faraj, F. Hachem, H. Bazzi, M. Khaled, and C. Castelain, “Analysis of underfloor electrical heating system integrated with coconut oil- PCM plates,” Applied Thermal Engineering, vol. 158, article 113778, 2019.
View at: Publisher Site | Google Scholar
M. Rezvanpour, D. Borooghani, F. Torabi, and M. Pazoki, “Using CaCl₂6H₂O as a phase change material for thermo-regulation and enhancing photovoltaic panels' conversion efficiency: experimental study and TRNSYS validation,” Renewable Energy, vol. 146, pp. 1907–1921, 2020.
View at: Publisher Site | Google Scholar
Y. Zhang and X. Zhang, “Thermal properties of a new type of calcium chloride hexahydrate-magnesium chloride hexahydrate/expanded graphite composite phase change material and its application in photovoltaic heat dissipation,” Solar Energy, vol. 204, pp. 683–695, 2020.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2023 Parinaz Khaledi and Mahdi Behboodnia. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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