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Journal of Engineering Science and Technology Vol. 15, No. 3 (2020) 1731 - 1746 © School of Engineering, Taylor’s University

1731

EFFECTS OF DIFFERENT TILT ANGLES ON THE THERMO-ELECTRICAL PERFORMANCE OF A PV/PCM SYSTEM

ABDULMUNEM R. ABDULMUNEM1,3, *, PAKHARUDDIN MOHD SAMIN1, HASIMAH ABDUL RAHMAN2, HASHIM A. HUSSIEN3

1 School of Mechanical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor 81310, Malaysia.

2 Center of Electrical Energy System, School of Electrical Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, Johor 81310, Malaysia

3 Electromechanical Engineering Department, University of Technology, Baghdad 10066, Iraq *Corresponding Author: [email protected]

Abstract

The use of phase change material (PCM) for enhancing the thermal effect of photovoltaic (PV) panels has been studied by a number of researchers in recent years. Tilt angle of the installed PV panels has a great influence on the power generation especially for the fixed type installation. This study presents an experimental-based approach to investigate the effects of utilizing PCM to manage the PV system’s thermal behaviours. It includes (1) the effects of different PV/PCM system’s tilt angles on the PCM’s melting behaviour that causes the rising the system’s temperature, (2) the effects of convection heat transfer mechanism with different tilt angle on the heat transfer inside PV/PCM container, and (3) the effects on the PV panel electrical performance-enhancing. The tilt angles used in this study are 0o, 30o, 60o and 90o. The results show that the increase in the PV/PCM system tilt angle from 0o to 90o led to a decrease in the PV’s cell temperature from -0.4% to -12%, due to the fact of the overwhelming effect of the natural convection regime inside PCM container as a passive cooling mechanism. As a result, the PV cell’s electrical performance is improved where Isc decreases from -0.1% to -3%, Voc increases from 0.2% to 7%, and the fill factor increases from 0.1% to 3%. With these improvements, the electrical efficiency of the PV cell is increased from 0.2% to 5%.

Keywords: Convection, Melting behaviour, PCM, PV, Tilt angle.

1732 A. R. Abdulmunem et al.

Journal of Engineering Science and Technology June 2020, Vol. 15(3)

1. Introduction In general, Photovoltaic (PV) system is one of the most popular technologies for renewable energy generation where it converts sunlight into usable electrical energy [1]. In a PV cell, electricity is generated by the photons energy levels resulted from the incoming solar radiation. However, the radiation also produces heat on the cell which causes an increase in its temperature. As a result, the cell’s efficiency drops significantly since its efficiency is greatly influenced by the temperature. Therefore, to optimize PV cell’s efficiency, the increase in its temperature must be kept as minimum as possible.

Recent studies based on numerical and experimental approaches have reported that the temperature increase in the PV cells can be effectively managed using phase change material (PCM). For example, Brano et al. [2] and Ciulla [3] present a one-dimensional (1-d) model with a finite difference method for the PV/PCM system thermal modeling. Besides, the PV/PCM system has also been analyzed under Malaysian weather conditions by Mahamudul et al. [4].Next, Smith et al. [5] provide an evaluation of the power generated from the combined PV/PCM system based on different countries’ condition. Meanwhile, Atkin et al [6] describe a study on the effect of utilizing PCM additives to graphite combined with the finned heat sink on the PV system thermal management. The performance of three different PCM types used for thermal management of PV panels has been compared by Kibria et al.[7]. The effects of different thickness for the PCM layer on the PV cell’s capability to generate electricity were analysed by Park et al. [8]. In the integration of the building, the effect of PCM uses with PV panels has studied by Aelenei et al. [9]. The indoor investigation and numerical analysis of PV cell temperature regulation using coupled PCM/Fins are investigated by Abdulmunem et al. [10]. Nevertheless, in all the aforementioned numerical studies, only heat transfer through conduction inside the PCM structure was considered, even though heat transfer through convection also has significant effects on the PCM’s melting behaviours and the overall PV/PCM system thermal performance [11].

For two-dimensional (2-d) thermal models, there are also many studies that have been conducted. For example, Huang et al. [12] studied the thickness of the PCM layer, insolation and the effects of the ambient temperature on the PV system performance. The same authors have also analysed the PV/PCM system using two different PCM materials in the same container [13]. Subsequently, the PV system performance integrated with microencapsulates of PCM has been studied by Ho et al. [14]. Also, rapid changes in the PCM thermal specifications during the period of phase change were presented using mathematical models by Biwole et al. [15] and Groulx et al. [16]. The sidewalls of the PCM container for the studies in Biwole et al. [15] and Groulx et al. [16] were considered thermally insulated (adiabatic). So far, the thermal analysis in the 2-d models only considered height and thickness of the system. Thus, in the works by Huang et al. [17, 18], the losses of heat energy from the sidewalls of the used container were considered and analysed using three-dimensional (3-d) model. Next, the PV system integrated with microencapsulates of PCM has been analysed in the 3-d by Ho et al. [19, 20] by considering only conductive heat transfer inside the PCM.

In terms of experimental investigations on PV/PCM, Huang et al. [21] have studied the effects of using embedded fins in the PCM. Subsequent work in Huang et al. [22] describes the effects of the PCM crystalline segregation on the performance of PV/PCM system. Next, the PV/ PCM system performance using different types of

Effects of Different Tilt Angles on the Thermo-Electrical Performance of . . . . 1733


PCM have investigated by Hasan et al. [23]. In Indartono et al. [24], a study was carried out to investigate the performance of a PV/PCM system featuring yellow petroleum jelly as its PCM. Consequently, performance comparison between a PV system using white petroleum jelly with a mixture of graphite-copper, and a PV system using white petroleum jelly only was explained in Hachen et al. [25]. The effects of using PCM type RT 28 HC on the performance of the PV system, on the other hand, has been studied by Stropnik and Stritih [26]. Consequently, the BICPV (building integrated concentrated PV) systems using PCM for building thermal management was investigated by Sharma et al. [27]. The integration of the PV/ PCM system with a network of pipes to utilize the PCM's heat stored using water flow inside the pipes has been studied by Browne et al. [28, 29]. For the PV system, the thermal management using PCM was presented also in some review studies [30-34].

Based on the aforementioned studies, this work aims to experimentally show the effects of different tilt angles in the PV/PCM system on (1) the PCM melting behaviours, (2) the increase in the PV cell’s temperature, (3) the heat transfer inside PV/PCM container by convection mechanism and (4) the PV cell’s performance in electricity generation.

2. Methodologies

2.1. PV cell’s electrical performance

The PV cell’s electrical performance can be calculated using [35-37]:

𝐹𝐹𝐹𝐹 = 𝑃𝑃𝑚𝑚𝑚𝑚𝑚𝑚𝐼𝐼𝑠𝑠𝑠𝑠 𝑥𝑥 𝑉𝑉𝑜𝑜𝑠𝑠

(1) where: 𝑃𝑃𝑚𝑚𝑚𝑚𝑥𝑥 = 𝐼𝐼𝑚𝑚𝑚𝑚𝑚𝑚 𝑥𝑥 𝑉𝑉𝑚𝑚𝑚𝑚𝑚𝑚 (2)

Then the PV panel electrical efficiency is: 𝜂𝜂𝑒𝑒𝑒𝑒 = 𝑃𝑃𝑚𝑚𝑚𝑚𝑚𝑚

𝐺𝐺 𝑥𝑥 𝐴𝐴𝑃𝑃𝑃𝑃 (3)

where: FF = Fill factor, Isc = short-circuit current (A), Voc = open-circuit voltage (V), Pmax= maximum power (W), Vmpp = maximum power point voltage (V), Impp = maximum power point current (A), ηel = PV electrical efficiency (%), and G = Irradiation (W/m2).

2.2. Uncertainty analysis for the measured values

In this work, it can estimate the uncertainties for the measured values using the general formula [10]

𝑈𝑈 = �(𝜕𝜕𝜕𝜕 𝜕𝜕𝑣𝑣1� 𝐸𝐸1 )2 + (𝜕𝜕𝜕𝜕 𝜕𝜕𝑣𝑣2� 𝐸𝐸2 )2 + ⋯+ (𝜕𝜕𝜕𝜕 𝜕𝜕𝑣𝑣𝑛𝑛� 𝐸𝐸𝑛𝑛 )2 (4)

where, R is a given function of the independent variables v1, v2 to vn, with U the uncertainty in the result E1, E2 to En, represents the uncertainties of each independently measured variable as shown in Table 1.

Table 1. Measured variable uncertainties. Parameters Quantity Uncertainty (U) Irradiance (G) 1.5% Temperature (T) 1% Voltage (V) 0.5% Current ( I ) 0.5%



3. Experimental Setup The experimental set up is designed to investigate the effects of varying PV/PCM system’s tilt angle with constant irradiance and incidence values on (1) the PCM’s thermal performance and its temperature regulation, (2) the electrical efficiency enhancements in the PV/PCM integrated systems, and (4) the heat transfer inside PCM by convection and conduction mechanisms. One PV cell module with a dimension of 13.5cm (length) and 13.5cm (width), integrated with fully refined paraffin wax as its PCM, is investigated in this study. The type of PV cell used here is mono-crystalline and its maximum power output is 1.4 W at standard conditions (1000 W/m2 & 25 oC). The thermo physical properties of the used paraffin wax are given in Table 2.

Table 2 Thermo physical properties the used paraffin wax. Value Melting point 48 °C Flash point 200 °C Latent heat of fusion 142 kJ/kg Specific heat capacity 2 kJ/kg·K Density Solid phase (0.88 kg/l),

Liquid phase (0.77 kg/l) Thermal conductivity 0.2 W/m·K Volume expansion 14% Acidity No Oil content No Chemical classification Paraffin wax

Transparent polycarbonate container used in this study has the internal dimensions of 12.5 cm (length), 12.5 cm (width), 2.5 cm (depth), and 5 mm (thickness) so that the effects of the system tilt angle on the PCM melting behaviour can be clearly shown. An aluminum plate with 13.5 cm (length), 13.5 cm (width), and 0.7 mm (thickness) is used to cover the polycarbonate container on the side of the PV module. The aluminum plate is attached to the front side of the container and sealed with thermal RTV silicon adhesion to ensure that there is no leakage when the PCM fully melted. A thin layer of RS-type aluminum oxide thermal paste (3.5 W/m.K thermal conductivity) is used to close the air gaps between the PV module’s rear surface and the aluminum plate so that the heat transfer from the PV module to the PCM container can be improved. The thermo-physical properties of the aluminum plate with the transparent polycarbonate container and RTV silicon are given in Table 3.

Table 3. Thermo-physical properties of the used aluminum sheet with transparent polycarbonate container and RTV silicon.

Property Aluminum Polycarbonate Silicon Specific heat (cp), kJ/kg.K 0.917 1.17 0.716 Density (ρ), kg/m3 2700 1300 2330 Thermal conductivity (k), W/m.K

238 0.19 157

Melting temperature, °C 660 220 1410 Absorptivity 0.059 0.8 0.02



A constant irradiance of 1000 W/m2 is provided in the test rig by a 500 W halogen sun simulator so that the effects of a temperature gradient at the fixed irradiance on the PV/PCM system thermal performance can be studied. An adjustable stand is used to control the tilt angles of the PV modules so that the tilt angle can be varied with a fixed irradiance value and direction. Temperature distribution inside the PCM module, on the other hand, is measured using two-column K-type thermocouples with an accuracy of ±0.2 °C (each column with 5 thermocouples). The thermocouples are placed at a distance of 1 cm and 2 cm, respectively, and the distance between them in the column is 2 cm. In addition, another two thermocouples are used in this work, where one of them is fixed on the PV panel surface and the other is used for measuring the test room’s air temperature. The thermocouples are directly connected to 12-channel data logger type EXTECH-TM500 with an accuracy of ±0.01°C so that their readings can be recorded. The data are collected at an interval of every twenty minutes within 20 hours (5 hours for charging and 15 hours for discharge) for every tilt angle.

To measure the cell’s efficiency to generate electricity during the experiment, the maximum power point voltage (Vmpp), open-circuit voltage (Voc), maximum power point current (Impp), short-circuit current (Isc), fill factor (F.F) and electrical efficiency are measured using PV trace analyzer type PROVA-218 with ±1% accuracy. Solar power meter type TES-1333 with ±3 W/m2 accuracy is also used to measure the solar intensity incidence on the photovoltaic module.

The experimental setup is prepared in the laboratory for renewable energy in School of Mechanical Engineering, Universiti Teknologi Malaysia. The schematic diagram and the photograph of the actual experimental setup are illustrated in Figs. 1 and 2, respectively.

Fig. 1. The experimental setup schematic diagram, 1) PC, 2) PV analyzer, 3) Digital thermo recorder, 4) Light intensity meter, 5) Digital Camera,

6) PV/PCM model, 7) Sun simulator, 8) PCM container, 9) PV cell.



Fig. 2. The experimental setup’s actual photograph, 1) Light intensity meter, 2) PV analyzer, 3) Digital thermo recorder, 4) Digital Camera,

5) PV/PCM model, 6) Sun simulator, 7) Thermocouples’ outlet, 8) Expansion space, 9) Fill tube

4. Results and Discussion The flow and temperature fields characteristics’ inside the PV/PCM system container are examined experimentally by exploring the effects of tilt angle on the melting process inside the PCM container. All the experimental results are obtained based on a constant irradiance 1000 W/m2 applied on the PV/PCM system.

The results of the melting process inside the rectangular container are presented in Fig. 3 with the tilt angles 90°, 60°, 30°, and 0°. For all tilt angles, the heat transfer by the hot surface (PV cell) to the melting zone happens predominantly through conduction during the early stage of the experiment. This mode of heat transfer prevails as long as the viscous force opposing the fluid motion during which the solid-liquid interface remains uniform and almost parallel to the hot surface and. However, as the melting progresses, the melted region expands and the heat transfer is now performed through convection instead of conduction.

At the tilt angles of 90o, 60o, and 30o, the high melting occurs near the top interface of the solid-liquid due to change in the density of the hot fluid (less density) and going up then impinges to the top container wall. The heat is transferred to the melting area, and the cold liquid then descends down due to its higher density relative to hot liquid. Thus, the melting rate at the bottom is significantly lower than that at the top. This circulation mechanism is more effective in vertical angle (90o) than others angles (60o and 30o) due to the increase in the friction force between the hot fluid and the PV surface with decreasing tilt angle, which decreases the convection effect.

From the melting process in the container with 0° tilt angle, it can be observed that the heat transfer by convection is eliminated (non-obvious effect). Instead, the heat transfer here is dominated by conduction. So, after 240 min, a large amount of PCM still remains in solid state due to low thermal conductivity of PCM. For a



comparison, the PCM melted completely at the tilt angle of 90o after 240 min due to the significant effect of convection.

90o

60o

30o

0o

Fig. 3. PCM melting processes inside PV/PCM container with different tilt angles.



The effects of different tilt angle on (1) the PCM’s temperature (during charging and discharging) at different locations inside the PCM container and (2) the PV cell temperature are presented in Fig. 4. Initially, due to the heat conduction, the PCM's temperatures increase inside the solid PCM. Then, the temperature at the positions 1, 2, 3, 4, and 5 increase at a higher rate than the temperature measured at 6, 7, 8, 9, and 10. The reason for this is that the heat is transferred inside the solid PCM at positions 1, 2, 3, 4, and 5 by the strong heat conduction through the thin hot layer of the liquid PCM.

During the PCM melting process, it can be seen that at the tilt angles of 90o, 60o and 30o, the temperature decreases, with the increasing time, from the upper to the lower positions inside the PCM container. This confirms the presence of the clockwise rotating flow in the liquid during the effects of convection heat transfer. This convection effect accelerates the PCM melting process inside the container (see Fig. 3). Meanwhile, at 0o tilt angle, the temperatures at positions 1, 2, 3, 4, and 5 increase quite uniformly with no significant fluctuations. The same trend can also be observed at positions 6, 7, 8, 9, and 10. Therefore, it can be deduced that the development in the melt layers by regular conduction heat transfer in the liquid region has no obvious effects on the convection heat transfer.

90o

60o



30o

0o

Fig. 4. The tilt angle effects on the PCM’s temperature at different locations inside the PCM container.

Fig. 5. Comparison of PV cell’s temperature with different tilt angles.



Since the efficiency of a PV cell is affected by temperature, an increase in the temperature leads to a decrease in the power generated from the PV/PCM system. From the PV analyzer, Fig. 6 presents the I-V, P-V trace with an electrical performance of the PV/PCM system tilt angle at the end of charge time (300 min). Figure 7, on the other hand, shows a comparison of the data from Fig. 6. Based on the figure, the vertical tilt angle (90o) gives the best electrical performance with higher maximum power generated (Pmax) and the open-circuit voltage (Voc) with lower in the short circuit current (Isc). This is due to the effects of the natural convection that plays a role as a passive cooling mechanism for the PV cell. When the tilt angle decreases, the PV cell’s temperature increases as well, resulting in a drop of the PV cell’s electrical performance. The drop happens due to less effective convection heat transfer with the decrease of the PV/PCM’s tilt angle. Hence, Pmax and Voc are reduced with an increase in Isc.

90o 60o

30o 0o

Fig. 6. I-V, P-V trace with an electrical performance at the end of the charging (300 min).

Fig. 7. I-V, PV curve comparison for PV cell with

different tilt angle at the end of the charging (300 min).



The recorded data for the PV/PCM systems’ electrical performance, measured using a PV analyzer during charging, are presented in Figs. 8-11. Based on these figures, it can be observed that the best performance for Vmax, Voc, F.F., Pmax, electrical efficiency and lowest in Isc can be achieved by the PV/PCM system with a tilt angle of 90o. Such tilt angle offers the best performance due to the effects of the convection heat transfer in reducing the heat. This electrical performance will drop with a decrease in the PV/PCM’s tilt angle since smaller tilt angle causes an increase in the PV cell’s temperature.

(a)

(b)

Fig. 8. Effects of PV/PCM tilt angles on a) Isc, b) Impp during charging.

(a)



(b)

Fig. 9. Effects of PV/PCM tilt angles on a) Voc, b) Vmpp during charging.

(a)

(b)

Fig. 10. Effects of PV/PCM tilt angles on a) Pmax, b) filling factor during charging.



Fig. 11. Effects of PV/PCM tilt angle on the electrical efficiency during charging.

Finally, Fig. 12 presents the results, in terms of percentage, of the PV cell’s temperature drop and the electrical performance enhancements for the system’s different tilt angles. The percentage is calculated comparative to the PV cell without PCM. Based on the figure, an increase in the system’s tilt angle from 0o to 90o contributes in decreasing the PV cell’s temperature from -0.4% to -12%. This leads to improvements in the electrical performance of the PV cell in terms of Isc (decrease from -0.1% to -3%), Voc (increase from 0.2% to 7%), and fill factor (F.F) (increase from 0.1% to 3%). These improvements eventually lead to an increase in the electrical efficiency of the PV cell from 0.2% to 5%.

Fig. 12. The percentage of PV cell temperature dropping

and electrical performance enhancement with different PV/PCM system tilt angle comparative with PV cell without PCM

5. Conclusions From this study, it can be concluded that by increasing the tilt angle of the

PV/PCM system, the convection heat transfer becomes more effective than the conduction heat transfer in accelerating the melting behaviours of the PCM inside the PV/PCM system. An increase of the tilt angle from 0o to 90o contributes in reducing the PV cell’s temperature from -0.4% to -12%. As a result, the electrical performance of the cell improves, which eventually leads to the increase of the cell’s electrical efficiency from 0.2% to 5%.



Nomenclatures cp Specific heat, kJ/kg.K E1, E2 to En Uncertainties of each independently measured variable F.F Fill factor G Irradiation, W/m2 Impp Maximum power point current, A Isc Short-circuit current, A k Thermal conductivity, W/m.K Pmax Maximum power, W R A given function T Temperature, oC U Uncertainty Vmpp Maximum power point voltage, V Voc Open-circuit voltage, V v1, v2, . .vn Independent variables Greek Symbols ηel PV electrical efficiency,%, ρ Density, kg/m3 Abbreviations

PCM Phase change material PV Photovoltaic

References 1. Hu, J.; Chen W.; Yang, D.; Zhao, B.; Song, H.; and Ge, B. (2016). Energy

performance of ETFE cushion roof integrated photovoltaic/thermal system on hot and cold days. Applied Energy, 173, 40-51.

2. Brano, V.L.; Ciulla, G.; Piacentino, A.; and Cardona, F. (2014). Finite difference thermal model of a latent heat storage system coupled with a photovoltaic device: description and experimental validation. Renew Energy, 68, 181-193.

3. Ciulla, G.; Brano, V.L.; Cellura, M.; Franzitta, V.; and Milone, D. (2012). A finite difference model of a PV-PCM system. Energy Procedia, 30, 198-206.

4. Mahamudul, H.; Rahman, M.M.; Metselaar, H.S.C.; Mekhilef, S.; Shezan, S.A.; Sohel, R.; Abu Karim, S.; and Badiuzaman, W.N.I. (2016). Temperature regulation of photovoltaic module using phase change material: a numerical analysis and experimental investigation. Int J Photoenergy, 1-8, 5917028.

5. Smith, C.J.; Forster, P.M.; and Crook, R. (2014). Global analysis of photovoltaic energy output enhanced by phase change material cooling. Appl Energy, 126, 21-28.

6. Atkin, P.; and Farid, M.M. (2015). Improving the efficiency of photovoltaic cells using PCM infused graphite and aluminium fins. Sol Energy, 114, 217-228.

7. Kibria, M.A.; Saidur, R.; Al-Sulaiman, F.A.; and Aziz, M.M.A. (2016), Development of a thermal model for a hybrid photovoltaic module and phase change materials storage integrated in buildings. Sol Energy, 124, 114-123.



8. Park, J.; Kim T.; and Leigh, S.B. (2014). Application of a phase-change material to improve the electrical performance of vertical-building-added photovoltaics considering the annual weather conditions. Sol Energy, 105, 561-674.

9. Aelenei, L.; Pereira, R.; Gonçalves, H.; and Athienitis, A. (2014). Thermal performance of a hybrid BIPV-PCM: modeling, design and experimental investigation. Energy Procedia, 48, 474-483.

10. Abdulmunem, R.A.; and Jalil, M.J. (2018). Indoor investigation and numerical analysis of PV cells temperature regulation using coupled PCM/Fins. International Journal of Heat and Technology, 36 (4), 1212-1222.

11. Kant, K.; Shukla, A.; Sharma, A.; and Biwole, P.H. (2016), Heat transfer studies of photovoltaic panel coupled with phase change material. Sol Energy, 140, 151-161.

12. Huang, M.J.; Eames, P.C.; and Norton, B. (2004). Thermal regulation of building-integrated photovoltaics using phase change materials. Int J Heat Mass Transf, 47, 2715-2733.

13. Huang, M.J. (2011). The effect of using two PCMs on the thermal regulation performance of BIPV systems. Sol Energy Mater Sol Cells, 95, 957-963.

14. Ho, C.J.; Tanuwijava, A.O.; and Lai, C.M. (2012). Thermal and electrical performance of a BIPV integrated with a microencapsulated phase change material layer. Energy Build, 50, 331-338.

15. Biwole, P.H.; Eclache, P.; and Kuznik, F. (2013), Phase-change materials to improve solar panel's performance. Energy Build, 62, 59-67.

16. Groulx, D.; and Biwole, P.H. (2014). Solar PV passive temperature control using phase change materials. In: 15th international heat transfer conference, Kyoto, Japan.

17. Huang, M.J.; Eames, P.C.; and Norton, B. (2006). Comparison of a small-scale 3D PCM thermal control model with a validated 2D PCM thermal control model. Sol Energy Mater Sol Cells, 90, 1961-1972.

18. Huang, M.J.; Eames, P.C.; and Norton, B. (2007), Comparison of predictions made using a new 3D phase change material thermal control model with experimental measurements and predictions made using a validated 2D model. Heat Transf Eng, 28, 31-37.

19. Ho, C.J.; Chou, W.L.; and La,i C.M. (2015). Thermal and electrical performance of a water surface floating PV integrated with a water-saturated MEPCM layer. Energy Convers Manag, 89, 862-872.

20. Ho, C.J.; Chou, W.L.; and La,i C.M. (2014). Application of a water-saturated MEPCM-PV for reducing winter chilling damage on aqua farms. Sol Energy, 108, 135-145.

21. Huang, M.J.; Eames, P.C.; and Norton, B. (2006). Phase change materials for limiting temperature rise in building integrated photovoltaics. Sol Energy, 80, 1121-1130.

22. Huang, M.J.; Eames, P.C.; Norton, B.; and Hewitt, N.J. (2011). Natural convection in an internally finned phase change material heat sink for the thermal management of photovoltaics. Sol Energy Mater Sol Cells, 95, 1598-1603.



23. Hasan, A.; McCormack, S.J.; Huang, M.J.; and Norton, B. (2010). Evaluation of phase change materials for thermal regulation enhancement of building integrated photovoltaics. Sol Energy, 84, 1601-1612.

24. Indartono, Y.S.; Suwono, A.; and Pratama, F.Y. (2014). Improving photovoltaics performance by using yellow petroleum jelly as phase change material. Int J Low-Carbon Technol, 0, 1-5.

25. Hachem, F.; Abdulhay, B.; Ramadan, M.; El Hage, H.; El Rab, M.G.; and Khaled, M. (2017). Improving the performance of photovoltaic cells using pure and combined phase change materials - experiments and transient energy balance. Renew Energy, 107, 567-575.

26. Stropnik, R.; and Stritih, U. (2016). Increasing the efficiency of PV panel with the use of PCM. Renew Energy, 97, 671-679.

27. Sharma, S.; Tahir, A.; Reddy, K.S.; and Mallick, T.K. (2016). Performance enhancement of a Building-Integrated Concentrating Photovoltaic system using phase change material. Sol Energy Mater Sol Cells, 149, 29-39.

28. Browne, M.C.; Lawlor, K.; Kelly, A.; Norton, B.; and McCormack, S.J. (2015). Indoor characterization of a photovoltaic/thermal phase change material system. Energy Procedia, 70, 163-1671.

29. Browne, M.C.; Quigley, D.; Hard, H.R.; Gilligan, S.; Ribeiro, N.C.C.; Almeida, N.; and McCormack, S.J. (2016). Assessing the thermal performance of phase change material in a photovoltaic/thermal system. Energy Procedia, 91, 113-121.

30. Browne, M.C.; Norton, B.; and McCormack, S.J. (2015). Phase change materials for photovoltaic thermal management. Renew Sustain Energy Rev, 47, 762-782.

31. Ma, T.; Yang, H.; Zhang, Y.; Lu L.; and Wang, X. (2015). Using phase change materials in photovoltaic systems for thermal regulation and electrical efficiency improvement: a review and outlook. Renew Sustain Energy Rev, 43, 1273-1284.

32. Du, D.; Darkwa, J.; and Kokogiannakis, G. (2013). Thermal management systems for Photo- voltaics (PV) installations: a critical review. Sol Energy, 97, 238-254.

33. Shukla, A.; Kant, K.; Sharma, A.; and Biwole, P.H. (2017). Cooling methodologies of photovoltaic module for enhancing electrical efficiency: a review. Sol Energy Mater Sol Cells, 160, 275-286.

34. Sathe, T.M.; and Dhoble, A.S. (2017). A review on recent advancements in photovoltaic thermal techniques. Renew Sustain Energy Rev, 76, 645-672.

35. Hussien, H.A.; Noman, A.H.; and Abdulmunem, R.A. (2015). Indoor Investigation for Improving the Hybrid Photovoltaic /Thermal System Performance Using Nanofluid (AL2O3-Water). Engineering & Technology Journal , 33A(4), 889-901.

36. Hussien, H.A.; Noman, A.H.; and Abdulmunem, R.A. (2015). Improving of the photovoltaic/thermal system performance using water cooling technique. IOP Conference Series: Materials Science and Engineering, IOP Publishing.

37. Hussien, H.A.; Hasanuzzaman, M.; Noman, A.H.; and Abdulmunem, R.A. (2014). Enhance photovoltaic/thermal system performance by using nanofluid. Clean Energy and Technology (CEAT), 3rd IET International Conference on IEEE.

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