Performance Analysis of Concentrator Photovoltaic/Microchannel Heat Sink System Using Nanofluid

Author(s):  
Ali Radwan ◽  
Mohamed M. Awad ◽  
Shinichi Ookawara ◽  
Mahmoud Ahmed

Abstract In this study, the performance of concentrator photovoltaic (CPV) cell enhanced by using double layer microchannel heat sink (DL-MCHS) with nanofluid is investigated. Pure ethanol and 0.2 % Vol. Al2O3-ethanol are utilized to reduce the solar cell temperature under indoor solar concentration ratio of 5.7 Suns. The designed DL-MCHS is monolithically fabricated from Maraging steel using 3D metal printer. The experimental results showed that using parallel flow (PF) operation mode of the designed DL-MCHS is favourable for cooling the CPV system compared with the counter flow (CF) operation mode. In the cooled CPV using PF mode, the open circuit voltage enhancement is about 12.7% in comparison to the uncooled case. The nanofluid results also showed a reduction in the solar cell temperature in comparison with the pure coolant. The current results can be used as a validation step for accurate numerical modelling of nanofluid applications in CPV system cooling.

Author(s):  
Ali Radwan ◽  
Mahmoud Ahmed ◽  
Shinichi Ookawara

The photovoltaic output power is directly proportional to the solar radiation and inversely with the cell temperature. The higher the photovoltaic temperature is, the lower the electrical efficiency is with possible damage to the cell. To improve the electrical efficiency and to avoid the possible damage, a concentrating PV system associated with an effective cooling technique is of great importance. In the present study, a new cooling technique for concentrated photovoltaic (CPV) systems was introduced using various designs of micro-channel heat sinks. The suggested configurations included parallel flow, counter flow single and double layer micro-channels, and single layer flat micro-channel integrated with CPV system. A comprehensive three-dimensional thermo-fluid model for photovoltaic layers integrated with microchannel heat sink was developed. The model was simulated numerically to estimate the solar cell temperature. The numerical results were validated with the available experimental and numerical results. In the meantime, the effects of different operational parameters were investigated such as solar concentration ratio and cooling mass flow rate. Performance analysis of CPV using different microchannel configurations was implemented to determine the average and local solar cell temperature, pumping power, and temperature uniformity. Results indicated that the use of microchannel heat sink was a very effective cooling technique which highly attained temperature uniformity, viz., eliminated the hot spots formation with a significant reduction in the average temperature of CPV. The single layer parallel flow achieved the minimum solar cell temperature while the counter flow attained the most uniform temperature distribution compared with other configurations. Furthermore, the double layer parallel flow microchannel attained the minimum pumping power for a given cooling mass flow rate.


Author(s):  
Ali Radwan ◽  
Mohamed M. Awad ◽  
Shinichi Ookawara ◽  
Mahmoud Ahmed

Abstract In this study, a new design of double layer microchannel heat sink (DL-MCHS) has been monolithically fabricated using 3D metal printer and experimentally examined as a heat sink for concentrator photovoltaic (CPV) systems. Single phase liquid cooling using ethanol and flow boiling cooling using NOVEC-7000 coolant in the designed DL-MCHS are experimentally compared. The results proved that using the flow boiling cooling technique for the CPV systems attained a lower solar cell temperature with high temperature uniformity. In more details, flow boiling in counterflow (CF) operated DL-MCHS, attained a very low solar cell temperature close to the NOVEC-7000 boiling point with temperature uniformity of 0.2 °C over a wide range of coolant flow rate from 25–250 ml/hr.


Author(s):  
Ali Radwan ◽  
Mahmoud Ahmed ◽  
Shinichi Ookawara

The high incident heat flux on the concentrated photovoltaic (CPV) system causes a significant increase in the cell temperature and thus reduces the system efficiency. Therefore, using an efficient cooling technique is of great importance for those systems. In the present study, a new technology for concentrated photovoltaic systems is introduced using a truncated-double layer microchannel heat sink. A comprehensive three-dimensional thermo-fluid model for the photovoltaic layers integrated with a microchannel heat sink was developed. The proposed model was simulated numerically to estimate the solar cell temperature, temperature uniformity, cooling system pumping power, electrical efficiency and thermal efficiency of the CPV system. The numerical results were validated with the available experimental, analytical and numerical results in the literature. In the designed heat sink, various design parameters are investigated such as the truncation length, cooling mass flow rate, concentration ratio, and converging width ratio of the flow channel. Results indicate that increasing the truncated length leads to an increase of solar cell temperature at a constant coolant mass flow rate. The cell temperature varies between 80.1°C and 146.5°C as the truncation length ratio increases from 0 (i.e. single layer microchannel) to 1 respectively at a concentration ratio (CR) of 40 and a cooling mass flow rate (ṁ) of 26.6 g/min. Using the double layer microchannel reduces the consumed pumping power at the same total mass flow rate compared to the single layer microchannel. The Double layer configuration with a truncation length ratio (l/lsc) equal to unity achieves a lower pumping power and solar cell temperature uniformity in comparison to the single layer microchannel.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Myeong Sang Jeong ◽  
Yonghwan Lee ◽  
Ka-Hyun Kim ◽  
Sungjin Choi ◽  
Min Gu Kang ◽  
...  

In the fabrication of crystalline silicon solar cells, the contact properties between the front metal electrode and silicon are one of the most important parameters for achieving high-efficiency, as it is an integral element in the formation of solar cell electrodes. This entails an increase in the surface recombination velocity and a drop in the open-circuit voltage of the solar cell; hence, controlling the recombination velocity at the metal-silicon interface becomes a critical factor in the process. In this study, the distribution of Ag crystallites formed on the silicon-metal interface, the surface recombination velocity in the silicon-metal interface and the resulting changes in the performance of the Passivated Emitter and Rear Contact (PERC) solar cells were analyzed by controlling the firing temperature. The Ag crystallite distribution gradually increased corresponding to a firing temperature increase from 850 ∘C to 950 ∘C. The surface recombination velocity at the silicon-metal interface increased from 353 to 599 cm/s and the open-circuit voltage of the PERC solar cell decreased from 659.7 to 647 mV. Technology Computer-Aided Design (TCAD) simulation was used for detailed analysis on the effect of the surface recombination velocity at the silicon-metal interface on the PERC solar cell performance. Simulations showed that the increase in the distribution of Ag crystallites and surface recombination velocity at the silicon-metal interface played an important role in the decrease of open-circuit voltage of the PERC solar cell at temperatures of 850–900 ∘C, whereas the damage caused by the emitter over fire was determined as the main cause of the voltage drop at 950 ∘C. These results are expected to serve as a steppingstone for further research on improvement in the silicon-metal interface properties of silicon-based solar cells and investigation on high-efficiency solar cells.


Vacuum ◽  
2016 ◽  
Vol 128 ◽  
pp. 91-98 ◽  
Author(s):  
Sheng Ge ◽  
Haitao Xu ◽  
Wenzhen Wang ◽  
Runan Cao ◽  
Yanglin Wu ◽  
...  

2009 ◽  
Vol 48 (24) ◽  
pp. 4402-4405 ◽  
Author(s):  
Elizabeth A. Gibson ◽  
Amanda L. Smeigh ◽  
Loïc Le Pleux ◽  
Jérôme Fortage ◽  
Gerrit Boschloo ◽  
...  

2015 ◽  
Vol 5 (4) ◽  
pp. 682-694 ◽  
Author(s):  
Lu Wang ◽  
Jianshu Han ◽  
Anthony Lochtefeld ◽  
Andrew Gerger ◽  
Allen Barnett

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Yi-Chun Chen ◽  
Chao-Ying Yu ◽  
Chih-Ping Chen ◽  
Shu-Hua Chan ◽  
Ching Ting

A novel soluble conjugated polymers, P2, with coplanar thiophene-phenylene-thiophene unit is designed and synthesized as suitable active material used in tandem cells to compensate the poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl-C71 butyric acid methyl ester (PC71BM) bulk-heterojunction cell in this paper. P2 polymer bears advantages in both low optical bandgap (1.7 eV) and high hole mobility properties (3.4×10−3 cm2/V-s from field-effect transistor measurement). Furthermore, the electrochemical studies of P2 indicate desirable highest occupied molecular orbital/lowest unoccupied molecular orbital (HOMO/LUMO) band structure that enables a high open circuit voltage when pairing with PCBM acceptor. The best power conversion efficiency of this polymer solar cell thus far based on P2/PC71BM system with a weight ratio of 1:3 reached 4.4% with a short circuit current density (Jsc) of 10.2 mA/cm2, an open circuit voltage (Voc) of 0.81 V, and a fill factor (FF) of 0.53 under air mass (AM) 1.5 G (100 mW/cm2). The preliminary data of the tandem cell with indium tin oxide (ITO) glass/PEDOT:PSS/P2:PC71BM/TiOx/PEDOT:PSS/P3HT:PC71BM/TiOx/Al configuration has reached Jsc of 6.2 mA/cm2, Voc of 1.33 V, FF of 0.56 and an overall efficiency of 4.6% under AM 1.5 G (100 mW/cm2).


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