Concentrator Photovoltaic Cells Research Articles

Enhancing efficiency of dense array CPV receivers with controlled DC-DC converters and adaptive microfluidic cooling under non-uniform solar irradiance

Concentrating solar technologies offer substantial potential for optimizing solar energy for heat and power generation, particularly in green hydrogen production. This study investigates the use of commercial high efficiency concentrated photovoltaic (CPV) cells in a central tower concentrating solar system to enhance energy conversion efficiency. By integrating DC-DC converters with self-adaptive microfluidic cooling systems, we address current mismatches and temperature variations that affect CPV performance. The novel receiver design ensures scalability for large-scale implementations by implementing the electrical connections between DC-DC converters and each CPV cell without creating shaded areas. We numerically model and simulate the thermodynamic and electrical characteristics of a dense array CPV receiver, evaluating six illumination profiles. Our results indicate a significant improvement in receiver efficiency compared to the traditional configuration with bypass diodes, demonstrating an increase from 23.4 % to 30.3 % under a central Gaussian illumination profile, and reaching up to 38 % relative efficiency improvement depending on the applied profile. Power transfer losses decrease from 26 % to 10 % when 200 kW/m2 of illumination non-uniformity occurs. The proposed solution enhances reliability and energy conversion efficiency, presenting a viable path forward for large-scale CPV applications.

Cpvlib: A comprehensive open-source tool for modeling CPV systems

The design and simulation of concentrator photovoltaic (CPV) systems necessitate precise modeling tools, for which some commercial and open-source options exist. However, when new technologies or applications need to be modeled, they can present some limitations: lack of documentation transparency and inability to extend existing models, or little flexibility to do it. For instance, the novel hybrid CPV/flat-plate module, conceived by Insolight and developed within the HIPERION project, required the ability to model integrated tracking and dual use of incident irradiance, which was not possible with existing tools. Addressing these issues, cpvlib is introduced as a comprehensive, open-source tool offering modular and adaptable functionalities for CPV-based systems, built as an extension of the popular pvlib python library.cpvlib's design enables the simulation of various CPV-based configurations, incorporating advanced architectures such as integrated tracking and hybrid CPV-flat plate modules. The library uses PVSyst's utilization factors to model deviations from the single-diode model, accounting for spectral and thermal effects. Its class structure leverages object-oriented programming principles, ensuring ease of use and extension.The validation of cpvlib is carried out through the modeling and long-term monitoring of Insolight's hybrid Si/III-V translucent planar micro-tracking modules, achieving a root mean square error of 3.5 % in case of Si cells and 2.7 % for III-V CPV cells. The tool accounts for complex behaviors like air mass impact on CPV performance, angle of incidence limits, and light spillage. The annual energy yield for a hybrid module is computed using typical meteorological year data, showcasing cpvlib's practical application.

Techno-economic viability of sustainable solar co-generation using CPV cells in parabolic dish concentrators: A 20-year perspective

Solar co-generation is a cutting-edge technology that enables the instantaneous production of electricity and heat energy by employing concentrated solar power (CSP) systems. This study presents the development and experimental analysis of a novel small-scale solar co-generation system, utilizing concentrated photovoltaic (CPV) cells integrated into a solar paraboloidal dish concentrator (SPDC) for simultaneous electricity and heat production. The system, designed with a high concentration ratio, employs a CPV module composed of four 1 cm × 1 cm cells mounted on a flat receiver of a parabolic dish concentrator with an aperture area of 12.6 m2. Experimental results, obtained over three consecutive days, demonstrate that the CPV module achieves an electric power output ranging from 480 to 645 W daily, while the SPDC system generates thermal energy between 395 and 725 W. The economic analysis indicates a cost of ₹10.75 per unit of electricity, with a payback period of approximately 13.5 years, assuming a 20-year system lifespan. Additionally, the reliability of the CPV module and the impact of varying encapsulation materials were critically assessed, providing insights into potential improvements and long-term performance. The findings underscore the viability and economic potential of solar co-generation systems employing CPV technology, contributing to the advancement of sustainable energy solutions.

Cooling of highly concentrated photovoltaic cells with confined jet impingement by introducing channel configurations

Appropriate cooling techniques are required to be integrated into highly concentrated photovoltaic cells to maintain the surface of the photovoltaic cell at a uniform temperature. This study focuses on cooling photovoltaic cells with confined jet impingement to reduce non-uniform temperature distribution and thermal and bending stresses to avoid hotspots and current mismatching problems, thereby improving the cell electrical efficiency. Channels are formed in an aluminium heat sink on the backside of solar cell layers such that the coolant strikes the heat sink surface at the centre and exits at the four corners of the module. Different designs of confined jet channel configurations are studied. The effect of the coolant mass flow rate on the hydrothermal performance of the concentrated photovoltaic thermal (CPV-T) system is examined for all channel configurations. The electrothermal performance of the CPV-T system is at its maximum with a quadrant mini-channel with a single inlet. The net electrical power generated by the PV cell is at its maximum of 30.5 W for a mass flow rate of 50 g/min with this channel configuration. Further, the pressure loss is minimal at 163 Pa at 25 g/min, and the temperature uniformity is also maximum, with a temperature difference over the cell surface of 6.3 °C at 50 g/min. The present study will be useful in the thermal management of highly concentrated photovoltaic thermal systems and high-temperature applications.

Performance of new hybrid heat sink with trimmed fins and microchannels for thermal control of a triple-junction concentrator photovoltaic cell

An efficient and low-cost cooling method for high concentrator photovoltaic systems is essential to improve the overall performance and prolong their lifetime. Therefore, a new cost-effective hybrid heat sink with trimmed fins and microchannels was developed to harvest the benefits of active and passive cooling techniques. Unlike the traditional heat sink designs, adopting trimmed fins saves the heat sink weight and cost without affecting its cooling performance. Thus, three different heat sink configurations, including (A) heat sink with trimmed fins, (B) microchannel heat sink, and (C) hybrid heat sink with trimmed fins and microchannels, were compared. A comprehensive three-dimensional model for the proposed heat sink designs coupled with the triple-junction cell was numerically simulated and solved using ANSYS FLUENT software to predict the cell temperature distribution, temperature uniformity, electrical efficiency, and net output power. Compared to the other trimming angles, the fin trimming angle (α) achieves a 20 % reduction in the heat sink weight and cost with no noticeable effect on its cooling performance. The new hybrid heat sink efficiently controls the cell temperature below 110 ˚C up to a high concentration ratio of 3600 suns, compared to 1220 suns and 3010 suns for configurations A and B, respectively. Furthermore, using the hybrid heat sink improves the electrical efficiency by 3 % and 3.2 % compared to configurations A and B, respectively. Generally, the hybrid heat sink achieves the maximum generated power of 123.7 W compared to 41.9 W and 103.4 W for configurations A and B, respectively.

Development of Low-Cost c-Si-Based CPV Cells for a Solar Co-Generation Absorber in a Parabolic Trough Collector

Concentrator photovoltaics (CPVs) have demonstrated high electrical efficiencies and technological potential, especially when deployed in CPV–thermal (CPV-T) hybrid absorbers, in which the cells’ waste heat can be used to power industrial processes. However, the high cost of tracking systems and the predominant use of expensive multi-junction PV cells have caused the market of solar co-generation technologies to stall. This paper describes the development and testing of a low-cost alternative CPV cell based on crystalline silicone (c-Si) for use in a novel injection-molded parabolic hybrid solar collector, generating both, photovoltaic electricity and thermal power. The study covers two different c-Si cell technologies, namely, passive emitter rear contact (PERC) and aluminum back surface field (Al-BSF). Simulation design and manufacturing are described with special attention to fingerprinting in order to achieve high current carrying capacities for concentrated sunlight. It was determined that Al-BSF cells offer higher efficiencies than PERC for the considered use case. Solar simulator tests showed that the highly doped 4 cm2 cells (50 ohm/sq) reach efficiencies of 16.9% under 1 sun and 13.1% under 60 suns at 25 °C with a temperature coefficient of −0.069%(Abs)/K. Finally, options to further improve the cells are discussed and an outlook is given for deployment in a field-testing prototype.

Thermal management of ultra high concentrator photovoltaic cells: Analysing the impact of sintered porous media microchannel heat sinks

Implementing advanced cooling strategies is essential to maintaining recommended operation conditions, enhancing energy efficiency, and extending the reliability of ultra-high concentrator photovoltaics. This study introduces a new application of sintered porous media as an effective and superior thermal management solution for ultra-high concentrator photovoltaic systems. Furthermore, predictive models for thermal and electrical performance are developed.A comprehensive three-dimensional computational fluid dynamics model was developed and verified against experimental work reported to investigate the performance of a novel sintered porous media for thermal management in ultra-high concentrator photovoltaics. Furthermore, the response surface methodology coupled with analysis of variance was used to analyze and comprehensively optimize the thermal management system. The main objective is to develop a predictive model for such systems equipped with a porous cooling system that predicts performance with a concentration ratio of up to 20000 Suns. Predictive models were formulated to outline the relationships between various independent variables: Reynolds number, concentration ratio, direct normal irradiance, wind speed, optical efficiency, fluid inlet temperature, and dependent performance metrics.This study highlights the effectiveness of sintered porous media in heat dissipation and efficiency enhancement in ultra-high concentrator photovoltaics thermal management. The results demonstrate that using sintered porous media compared to conventional channel heatsinks significantly enhances cell thermal management. Specifically, this approach reduces cell temperature by 15.3%, 8.97%, and 2% at concentration ratios of 20000, 10000, and 2000, respectively. Concurrently, implementing the new sintered porous media heatsink improves cell efficiency by 3.1%, 1.5%, and 0.3% for the same respective concentration ratio values.

Impact of DC-DC Converters on the Energy Performance of a Dense Concentrator PV Array under Nonuniform Irradiance and Temperature Profiles

Efficiency losses resulting from electrical mismatching in densely packed photovoltaic arrays present a significant challenge, particularly exacerbated in nonuniformly illuminated receivers and under varying temperatures. Serial configurations are particularly susceptible to radiation nonuniformities, while parallel systems are negatively affected by temperature variations. Various authors have recommended the incorporation of electrical voltage and current sources to mitigate these losses. This study explores different electrical connection configurations utilizing concentrated photovoltaic (CPV) cells and DC-DC electrical current converters. A self-adaptive microfluidic cell matrix cooling system is employed to mitigate thermal dispersion caused by the highly nonuniform illumination profile. The obtained results for each configuration are compared with the total electrical power produced by individual cells, operating under identical radiation and temperature conditions to those of the entire array. The results reveal a noteworthy increase in production across all studied configurations, with the parallel–series arrangement demonstrating the most promising practical utility. This configuration exhibited a remarkable 50.75% increase in power production compared with the standard series connection.

Mapping Solar Flux Distribution in Parabolic Trough Collectors to Assess Optical Performance

This paper describes the development and testing of a novel device capable of mapping the flux distribution in parabolic trough solar collectors (PTCs). Accurate knowledge about the flux distribution is essential in any concentrated solar power (CSP) application, in particular PTCs equipped with concentrator photovoltaic (CPV) cells, since their efficiency highly depends on the collector’s light focusing properties. However, the assessment of CSP collectors’ optical performance requires sophisticated measurement technology, as the error budget of any sun-tracking optical device comprises a variety of factors ranging from physical properties such as mirror reflectivity to mechanical aspects like gravity sag and play in gears. The presented approach features a scanner consisting of a CPV cell mounted on a pair of linear actuators. A thorough state of the art analysis was conducted and numerous technological approaches were assessed. Design aspects such as component selection, cooling, and data acquisition are discussed and finally exemplary measurement results are presented.

Performance Potential of a Concentrated Photovoltaic-Electrochemical Hybrid System

A novel hybrid system model, combining a concentrated photovoltaic cell (CPC) with a thermally regenerative electrochemical cycle (TREC), is proposed. This innovative setup allows the TREC to convert heat from the CPC into electricity. The model incorporates mathematical equations that explicitly define power output, energy efficiency, and exergy efficiency for both the CPC and the TREC individually, as well as for the hybrid system as a whole. The outcomes of the computations reveal that the hybrid system surpasses the performance metrics of the CPC alone. Specifically, the hybrid system achieves a notably higher maximum power density (MPD), maximum energy efficiency (MEE), and maximum exergy efficiency (MMEE) compared to the standalone CPC, with improvements of 392.68 W m−2, 10.33%, and 11.11%, respectively. Through thorough parametric analyses, it was observed that specific factors positively impact the hybrid system’s performance. These factors include higher operating temperatures, increased solar irradiation, specific concentration ratios, and alterations in the internal resistance or temperature coefficient of the TREC. However, it was noted that elevating the operating temperature of the CPC adversely affects the hybrid system’s performance. Furthermore, augmenting solar irradiation and optical concentration ratios amplifies the limiting electric current. Conversely, reducing the internal resistance of the TREC enhances the overall performance of the hybrid system. These discoveries have practical implications for optimizing the design and operation of a functional CPC-TREC hybrid system, providing valuable insights into maximizing its efficiency and effectiveness.

Novel designs for PCM passive heat sink of concentrated photovoltaic cells to enhance the heat transfer rate: presenting 4E analyses

Novel designs for PCM passive heat sink of concentrated photovoltaic cells to enhance the heat transfer rate: presenting 4E analyses

An experimental investigation on passive cooling of a triple-junction solar cell at high concentrations using various straight-finned heat sink configurations

The current study evaluates the energy, exergy, and environmental performance of concentrated triple junction photovoltaic (CPV TJ) cells at various concentration ratios with solar incident irradiance (CRs) ranging from 56 to 550 suns in Saudi Arabia during hot weather. Therefore, the integrated solar cells employed four distinct heat sinks: two with dimensions of 40 × 40 mm2, one with full straight fins (HS-A) and the other with chopped fins (HS-B), and the remaining two with dimensions of 150 × 70 mm2, one with full straight fins (HS-D) and the other with chopped fins (HS-C). The large heat sink (type-D) is 40.48% more efficient than the smaller one (type-B), which is only 39.7% efficient at a CR of 550. Regarding weight, the lighter heat sink (type-B) generates a higher relative power of roughly 1.22 W/g.cm2 than the heaviest one (type-D), which produces 0.22 W/g.cm2. According to exergy, the heat sink raised the solar cell improvement potential (IP) to 6.3, with exergy cost up to 0.085 $/cm2 higher than the uncooled cell. Based on an environmental study, combining the TJ cell with heat sinks reduces yearly carbon emissions by 311.9–327 tons/m2 compared to 43 tons/m2 for the uncooled cell.

Uniform cooling for concentrator photovoltaic cell by micro-encapsulated phase change material slurry in double-layered minichannels

The concentrator photovoltaic (CPV) systems often suffer high heat flux, leading to cell temperatures rising, which will affect its performance and reduce the service life. Double-layered minichannel heat sink (DL-MCHS) is an efficient cooling technology, which could effectively lower down the top temperature of CPV cell. Micro-encapsulated phase change material slurry (MPCS) is a novel type of latent heat functional fluid and has a good application prospect in the field of cooling. Therefore, MPCS flowing in the DL-MCHS, as the thermal management device was investigated for the cooling of CPV cell. Three configurations of minichannels, including staggered arrangement, parallel arrangement and dual unequal arrangement were compared and optimized. On the basis of optimization, the flow and heat transfer performance of MPCS with different concentrations in double-layered straight and wavy minichannels had been numerically studied. The results indicated that the lowest top temperature of dual unequal DL-MCHS obtained by counter arrangement could be reduced by 0.56 °C compared with the parallel arrangement at Re = 152. Both the ΔP and h were significantly influenced by concentrations. When Re reached 262, ΔP of 5 wt% MPCS in wave minichannel with 5 mm wavelength was 44 % larger than that of pure water in straight minichannel, which would consume more pumping power. However, the heat dissipation performance was improved significantly and Nusselt number in double-layered wavy minchannels also increased with the wavelength decreasing. Therefore, Performance Evaluation Criteria (PEC) was proposed to evaluate the overall performance, which was also greatly influenced by particle concentration and channel wavelength. After optimization, the highest PEC of MPCS in the wavy minichannel was achieved to 1.60. Because of the wavy minichannel with concave-convex structure, the obstacle of total thermal resistance became smaller for the wavelength decreasing. These findings of MPCS in minichannel can provide a good theoretical basis and engineering application in the cooling technology of CPV.

Performance analysis of a medium concentrated photovoltaic system thermally regulated by phase change material: Phase change material selection and comparative analysis for different climates

Thermal management of photovoltaic systems is important since their electrical output decreases with the increase in temperature. Thermal regulation of a photovoltaic system using a phase change material is an effective technique, but a careful selection of PCM in terms of its thermophysical properties is essential for its better performance. In this work, performance analysis of a novel medium concentrated photovoltaic system employing two mono-facial polycrystalline cells is carried out. The system is thermally regulated with a phase change material. An experimentally validated finite element-based coupled optical, thermal, and electrical model is used to analyze the system’s performance. The impact of the thermophysical properties of a PCM such as melting temperature, thermal conductivity, and heat of fusion on the thermal regulation of the system is studied using artificial neural networking methods. The optimum thermophysical properties of the PCM are determined using parametric analysis for the ambient temperatures ranging between 25 and 50 °C and a concentration ratio of 20×. Moreover, the performance of the system is analyzed using the optimum PCM for the semi-arid weather conditions of Lahore, Pakistan and the optimum PCM for oceanic weather conditions of Waterford, Ireland. It is found that the melting temperature, thermal conductivity, and heat of fusion of the PCM have a linearly indirect relationship with the temperature of the photovoltaic system while the ambient temperature has a linearly direct relationship with the photovoltaic system’s temperature. The melting temperature of a PCM should be 10–15 °C higher than the ambient temperatures up to the ambient temperature of 40 °C. The melting temperature of a PCM was found to be 5 – 10 °C higher than the ambient temperatures for ambient temperatures greater than 40 °C. The required thermal conductivity of a PCM increases with the increase in ambient temperature ranging from 10 to 12 Wm-1K−1 for the ambient temperature of 25 °C while 18–20 Wm-1K−1 for the ambient temperature of 50 °C. The suitable heat of fusion is found in the range of 210–220 kJkg−1. It is found that the optimum PCM for Lahore has melting temperature, thermal conductivity, and heat of fusion of 53–56 °C, 19 Wm-1K−1 and 220 kJkg−1 respectively. The optimum PCM for Waterford has melting temperature, thermal conductivity, and heat of fusion of 35–37 °C, 11 Wm-1K−1 and 220kJkg−1 respectively. The maximum temperature of concentrated photovoltaic cell for Lahore, Pakistan remains below 83 °C, while for Waterford, Ireland, it is below 59 °C for all the months in a year. From April to August, the output power is higher for Waterford with an average difference of 12%, while from September to March, Lahore has the higher power output with an average difference of 47%. The maximum power obtained for Lahore is 0.185kWh/day/m2, while for Ireland it is 0.213kWh/day/m2. A maximum deviation of 6% is found for electrical output and less than 3% for thermal output between simulated and experimental results during validation.

COOLING OF CONCENTRATED PHOTOVOLTAICS WITH PHASE CHANGE MATERIAL AND FINS

The increase in cell temperature with increased irradiance is probably the most significant disadvantage of using photovoltaic with reflector modules. In this study, a developed Phase Change Material system was integrated into the rear section of a concentrating Photovoltaic system to limit its temperature rise. The heat transmission of the concentrating photovoltaic with a phase change material system was investigated using an experimental method and a numerical method. The temperature distribution was simulated numerically using ANSYS 2021 three-dimensions model. Three cases were studied: one without wax, one with wax, and one with wax and fins. The results displayed convergence between the experimental results and the numerical results. The effect of using phase change materials on performance and efficiency of concentrated photovoltaic cells, the amount of temperature reduction through the wax melting period for concentration with paraffin wax and concentration photovoltaic with fin and paraffin wax by 2.8 °C and 6 °C, respectively, as well as an enhancement in efficiency of photovoltaic at the noon time of cases by 1.807% and 3.182% related to the reference photovoltaic. The outcomes also demonstrated that using fins aids in the distribution of temperatures, resulting in regular melting of wax in comparison to wax without fins.

A novel thermosyphon cooling applied to concentrated photovoltaic-thermoelectric system for passive and efficient heat dissipation

Concentrated photovoltaic-thermoelectric systems have received extensive research attention as a means of enhancing the utilization rate of solar energy. However, the expedited progress of these systems has been hindered by a myriad of challenges, such as the additional power consumption required for active cooling and the inadequate cooling rates of conventional passive cooling techniques. To overcome these limitations, a novel concentrated photovoltaic-thermoelectric system integrating thermosyphon cooling has been developed and subjected to a comprehensive analysis, encompassing its start-up performance, pipe resistance characteristics, and power generation performance have been analyzed. The results reveal that the buoyancy generated by the thermosyphon is 8.22 N, which effectively drives the speed of cooling water circulation to 0.011 m/s. The start-up time of the thermosyphon effect lengthens gradually with a decrease in inclination angle of heat sink, while the cooling temperature at the final stable state remains relatively consistent. Remarkably, at 240 kW/m2, the concentrated photovoltaic cell exhibits a remarkable heat dissipation power density of 15.26 W/cm2. Meanwhile, the optimal output voltage of concentrated photovoltaic is 1.907 V, at which the concentrated photovoltaic output power is 1.774 W. The optimal output voltage of thermoelectric is 0.528 V, at which the thermoelectric output power is 0.054 W. The results provide guidance for designing high-performance cooling systems for concentrated photovoltaic-thermoelectric systems.

Enhancement of concentrator photovoltaic system through convergent-divergent microchannels

Concentrated photovoltaic technology is one of the evolving technologies that converts solar to electrical energy with a high efficiency percentage. Increasing concentrated photovoltaic cell’s temperature significantly reduces the performance of the system. Thus, in order to properly functioning of system, thermal management will be a rudimentary issue. This article focuses on the cooling performance of high-concentration photovoltaic system using microchannels attached to the bottom plate of solar cell. To this end, the effect of convergent-divergent microchannels at three amplitudes and three wave lengths at different Reynolds numbers is investigated, and results are compared with simple microchannels. The output results are presented via temperature, pressure, velocity contours as well as Nusselt number, friction factor, and effectiveness ratio. Compared to the simple microchannels, convergent-divergent microchannel lowers the wall temperature about 0.4–2 Kelvin by making velocity gradients along the channel. This leads to boosting the heat transfer capability up to 3 times in the best case and up to 1.5 times in the worst case. Increasing the wave length enhances the performance of system, while the opposite trend has been seen for greater wave amplitudes. For case A with lowest wave length, Nu increases 1.92 and 2.4 times at lowest and highest Re numbers while friction factor increases due to the higher contact surface area along the fluid stream. Moreover, increasing the wave amplitude leads to higher Nu number, higher friction factor and consequently lower effectiveness ratio. Finally, effectiveness ratio as a criterion to choose best case has shown that a higher wave length alongside with lower wave amplitude offers better heat transfer enhancement and lower pressure drop compared to simple channel. Case C-1 as a best case offers 0.8K lower wall temperature, 1.6 times better Nu number with only 1.3-time higher friction factor.

Performance investigation of a concentrated photovoltaic-thermoelectric hybrid system for electricity and cooling production

To fully exploit inlet sunlight, a novel hybrid system comprising a concentrated photovoltaic cell, a thermoelectric generator, and a thermoelectric cooler is established. The thermoelectric generator generates electricity by thermally harnessing the solar spectrum energy unavailable to the concentrated photovoltaic cell and then drives the thermoelectric cooler to produce additional cooling. With full consideration of internal and external irreversibility, the numerical model of the hybrid system is developed, where comprehensive heat transfer equations are constructed by the effectiveness-number of transfer units method. Subsequently, the performance characteristics of the system are evaluated by energetic and exergetic analysis. Over the operating range of the thermoelectric unit, when the performance enhancement of the hybrid system is maximized, the associated power density, energy efficiency, and exergy efficiency are, respectively, 42.828 Wm-2, 0.0251, and 0.0255, which are improved by 3.53%, 3.72%, and 3.66% in comparison to the stand-alone concentrated photovoltaic system. Meanwhile, the exergy destruction rate density is reduced by 0.49%. Furthermore, comprehensive sensitivity analyses are undertaken to derive the effects of critical designing parameters and operating conditions on the overall performance. The obtained outcomes may contribute to the design and operation of such a cogeneration system.

Cooling of Concentrated Photovoltaic Cells—A Review and the Perspective of Pulsating Flow Cooling

This article presents a review to provide up-to-date research findings on concentrated photovoltaic (CPV) cooling, explore the key challenges and opportunities, and discuss the limitations. In addition, it provides a vision of a possible future trend and a glimpse of a promising novel approach to CPV cooling based on pulsating flow, in contrast to existing cooling methods. Non-concentrated photovoltaics (PV) have modest efficiency of up to around 20% because they utilise only a narrow spectrum of solar irradiation for electricity conversion. Therefore, recent advances employed multi-junction PV or CPV to widen the irradiation spectrum for conversion. CPV systems concentrate solar irradiation on the cell’s surface, producing high solar flux and temperature. The efficient cooling of CPV cells is critical to avoid thermal degradation and ensure optimal performance. Studies have shown that pulsating flow can enhance heat transfer in various engineering applications. The advantage of pulsating flow over steady flow is that it can create additional turbulence and mixing in the fluid, resulting in a higher heat transfer coefficient. Simulation results with experimental validation demonstrate the enhancement of this new cooling approach for future CPV systems. The use of pulsating flow in CPV cooling has shown promising results in improving heat transfer and reducing temperature gradients.

Performance of a Heat-Pipe Cooled Concentrated Photovoltaic/Thermoelectric Hybrid System

Compared to traditional one-sun solar cells, multijunction concentrator cells operating under concentrated solar radiation are advantageous because of their high output and low cooling costs. Such a concentrator PV requires a cooling technique to maintain its performance and efficiency. The performance of a multi-junction concentrator photovoltaic cell of efficiency around 33%, operating under concentrated solar radiation (160–250 sun), has been tested. Heat pipes were used in this study as a fast and efficient way of rejecting heat accumulated in the cells. In this work, the evaporator side of the heat pipe was set in thermal contact with the back side of the solar cell such that the excess heat was transferred efficiently to the other side (condenser side). To positively utilize such excessive heat, two thermoelectric generators were thermally attached to either side of the condenser of the heat pipe, and each was attached to a fin-shaped heat sink. Four different cooling configurations were tested and compared. The net power obtained by this concentrator solar cell employing two types of TEG with different lengths as a cooling alongside two thermoelectric generators for heat-to-electricity conversion was 20% and 17%, corresponding to the long and short heat pipe configurations, respectively, compared to traditional a heat sink only configured at an optical concentration of 230 suns.