Concentrator Photovoltaic Systems Research Articles

Photovoltaic Energy Production in Greenhouses With Spectral Splitting Solar Trackers

The spectral filtering low concentration photovoltaic system developed by Voltiris is an innovative solution for energy production in greenhouses without affecting food production. A first prototype was installed in the greenhouse of the agricultural research center Agroscope in Conthey, Switzerland. During an eight-month agronomic study from March to October, the yield of tomato, pepper bell and basil under this system was on a par with a control group. I-V curves were recorded to evaluate the photovoltaic system performance, and the impact of concentration and filtering. The curves showed that the prototype achieved a direct normal irradiation efficiency of 10.1 %. The specific power output of the Voltiris system inside the greenhouse was comparable to the one of a conventional solar panel placed outside. Filters with two different transmission spectra were used, both of which were matched to the absorption spectra of chlorophyll and reflected 50 % and 60 % of the incident global radiation respectively. To transfer the performance of the system to other greenhouses, the transmittance of the test greenhouse and its glass cover were measured for global and diffuse radiation. This allowed to determine the transmittance of the greenhouse specific metal structure. In the test greenhouse, the overall transmission coefficient for direct solar radiation was 0.28, hence limiting the system yield.

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.

ANN model of a triple-junction cell in concentrating photovoltaic system

Significant advancements in concentrating photovoltaic (CPV) systems have been achieved in recent years, also thanks to the definition of calculation methods of their energy performances in several operation conditions. Typically, the CPV systems electrical power is separately calculated or in terms of its temperature or concentration factor (C), but not simultaneously in terms of both variables. In this paper, an Artificial Neural Network model based on experimental data, linking electric power of CPV system with Direct Normal Irradiance and Triple-Junction cell temperature for different C values, is developed. Moreover, the model is also adopted to realize a feasibility analysis of point-focus CPV system used for different users: residential building and agricultural livestock farm. The optimal number of modules is determined to maximize the Net Present Value (NPV) of the investment. For the residential user, an optimal configuration of CPV system includes 16 modules, providing a peak power of 3.1 kW and covering an area of 130 m2. This configuration allows the maximization of NPV value, reaching 15.9 k€, with DPB of 9.8 years. As for the agricultural livestock, 36 modules, with peak power of 7.0 kW and covering an area of 292 m2, allow the maximization of NPV value equal to 16.3 k€, with DPB of 10.2 years.

Seasonal thermo-enviro-economic performance analyses of concentrated PV/T integrated with humidification-dehumidification water desalination system

Concentrated solar photovoltaic thermal offers a great opportunity for water desalination by applying some thermally driven techniques. Humidification–dehumidification water desalination is appropriate for moderate installations and runs on low temperatures matching the attainable output of low concentrated photovoltaic thermal systems. So, in this paper, thermo-enviro-economic performance analyses of an integrated system consisting of compound parabolic collectors partially covered with photovoltaic cells powering humidification dehumidification water desalination system is theoretically introduced. The system performance is conducted at a seasonal scale using MATLAB throughout the whole year under the weather of New Borg El-Arab city-Alexandria-Egypt. The results indicate that raising the flow rate of the working fluid of the system increases the desalination output, reduces the PV cell temperature, and enhances PV efficiency. At a fluid flow rate of 0.02 kg/s suitable for PV safety temperature, the cell maximum and minimum temperature are 79 and 42.5 °C, maximum and output power is 6 and 3.8 kW, and maximum and minimum efficiency is 17.2 and 14.2 % respectively. The output water temperature is 73 and 36.9 °C in summer and winter, respectively. The desalination system produces maximally 4.7, 6.2, and 3.8 L/h at water to air mass flow rate ratios of 1.5, 2, and 3, respectively. The maximum achieved average monthly desalination system gain output ratio is 3.15 with an overall system efficiency of 41 %. The average annual system thermal energy and exergy yield is approximately 176 and 0.2 kWh, respectively. The annual freshwater cost is $0.0351/Liter. The system mitigates an annual average of 7.2 tons of CO2 emissions.

Comparative Analysis of Reverse Truncated Pyramid and Other Nonimaging Concentrators as the Receiver in Laser Wireless Power Transmission System

The global energy landscape faces significant challenges in meeting the demands of modern industries for stable and efficient energy supply. Laser wireless power transmission (LWPT) systems, which utilize the photovoltaic effect to convert laser beam energy, hold great promise due to their long-range transmission capability and high precision. However, the current energy conversion efficiency of these systems requires further improvement to achieve optimal performance. To enhance concentrated photovoltaic (CPV) system performance, the study examines different nonimaging concentrators such as reverse truncated pyramid, cross-compound parabolic concentrator, and square elliptical hyperboloid. Numerical simulations using the finite element method analyze the multifield coupling mechanism of PV modules with various concentration lenses. Three CPV systems with RTP concentrators of different heights were studied to understand the impact of geometry on CPV performance. And the main impact of rotation angle was discussed. The research findings provide essential insights into CPV system performance and the influence of different concentration lenses, contributing valuable knowledge towards improving LWPT technologies.

Experimental Investigation of the Effect of Heat Pipe Tilting on a Concentrated Photovoltaic/Heat Pipe Passive Cooling System

Abstract To maintain the concentrated photovoltaic systems (CPV) output, effective cooling is necessary. In contrast to costly and complicated active cooling methods, passive cooling is static, simple, and maintenance-free. Among passive techniques, Heat Pipes (HPs) are devices that efficiently transfer heat from the evaporator to the condenser. The inclination angle of wicked, liquid-filled HP's long-axis determines how well it cools, as an effect of the gravitational force acting on the condensed liquid. This study investigates the effect of tilting the HP long-axis on the performance of the different parameters of the CPV, which is passively cooled by thermal attachment to its back side. Two similar HPs except for their lengths were attached alternatively. Different concentrated illumination levels are then allowed to be incident on the CPV. At each illumination level, the inclination of the HP long-axis was varied from −90 deg (completely vertical with condenser up) to 90 deg (completely vertical with condenser down), passing through 0 deg (HP is completely horizontal) with a step of 15 deg. The effect of such variations on the inclinations has been tested on the two systems. The system incorporating the long HP was found to have a higher cooling performance at an angle of −15 deg, compared to the short HP system, which has its highest cooling capacity at an angle of −60 deg, with an increase of about 7% for the maximum power in case of using the former system compared to the latter.

Integrated Model for Comprehensive Performance Investigation of Solar Concentrated Photovoltaic‐Thermal System Embedded with Microchannel Heat Sinks

Concentrated photovoltaic (CPV) is a well‐established renewable energy technology. A significant challenge in CPV systems is their low efficiency, majorly due to localized heating yielded from concentration, often requiring the use of cooling systems. The accurate performance analysis and cooling system design for CPV systems require a multiphysics model. Herein, an integrated optical–thermal–electrical model is proposed for the performance evaluation of CPV systems incorporated with different configurations of microchannel heat sinks. The heat sink configuration includes 116 parallel and counter microchannels (Configuration A and B), a single wide microchannel (Configuration C), and single wide minichannel (Configuration D) heat sinks. This study involves 3D Monte‐Carlo ray tracing, finite volume method, and cell‐based electrical modeling. The results indicate that the flux profile over the absorber is highly nonuniform in nature. Furthermore, the CPV system with a Configuration C heat sink achieves a better uniformity in temperature, providing an optimized thermal performance of 64.63%. Moreover, the integrated model considers the impact of PV cell current mismatch that becomes prominent at increasing incidence angles. A maximum deviation of 6.9% in electrical power is obtained while comparing predicted numerical results against experimental results available in literature.

A novel concentrated photovoltaic and ionic thermocells hybrid system for full-spectrum solar cascade utilization

Concentrated photovoltaic-thermoelectric generator (CPV-TEG) hybrid system can harvest the low-grade waste heat derived from photovoltaic cells to generate more electric energy. However, it is economically unfeasible due to the expensive cost of thermoelectric generators and higher photovoltaics temperature. Ionic thermocell based on thermogalvanic effect has a more inexpensive cost and ionic Seebeck coefficient of 1– 2 orders of magnitude higher than thermoelectric generators, which is promising for full-spectrum solar cascade utilization. In present work, a novel concentrated photovoltaic and ionic thermocells hybrid system (CPV-iTEC) is reported, aiming to comprehensively evaluate its feasibility. The ionic thermocell adhered directly to the photovoltaic panel consists the π-type multi-channels, electrodes and p/n-type redox electrolytes flowing in multi-channels, which can simultaneously cool photovoltaic panel and output electric energy for waste heat harvesting. A three-dimensional numerical model is proposed and validated by preliminary experiment to investigate the effects of structural and operating parameters on the performance of CPV-iTEC during energy, exergy and economic analyses. Results show that the optimal structural parameters of ionic thermocell are the 2 mm channel height and 1 mm width, showing a 7.18% higher energy efficiency than that of CPV-TEG at 10 concentration ratios. The presence of ionic thermocell can significantly decrease the photovoltaic panel temperature from 351.30 K to 325.14 K, and thus broaden the available concentration ratio from 1– 21 to 1– 39 compared with CPV-TEG, reaching a higher output power of 16.61 W. During the optimization of advanced redox electrolytes/electrodes, the energy efficiency can reach 49.63% at 21 concentration ratios, which is 5.06% higher than that of CPV-TEG, and show a 22.65% lower overall cost. The application of ionic thermocell in the full-spectrum solar cascade utilization of concentrated photovoltaic system is proved to be feasible with significant advantages of low cost, high performance, and flexible operation.

Heat pipe-cooled highly-concentrated multi-junction solar cell

Concentrator photovoltaic (CPV) systems have proven the capability of competing with traditional photovoltaic (PV) systems due to their high efficiency and low area occupancy. Such CPV systems require efficient heat removal auxiliary systems, especially for medium and high optical concentration ratios. Operating a CPV system under a high optical concentration (ratio > 200 X) might require active cooling techniques, which have high operating costs and maintenance. On the other hand, heat pipes (HPs) are widely used in electronic devices for cooling purposes. This work discusses the possibility of operating a CPV system coupled with HPs as a passive cooling technique. Two different HPs with different lengths are used to compare cooling efficiency. Each HP length was tested either in a single or double configuration. Long HPs showed better heat removal compared to a traditional fin-cooling system. CVP cooling with HP systems enhanced the entire electrical output of the cell, mainly at high optical concentration ratios.

Recent techniques for cooling of concentrated photovoltaic thermal systems

Recent techniques for cooling of concentrated photovoltaic thermal systems

CPV System Optical Performance Evaluation by Means of Direct Experimental Measurement Procedure

The optics is the component that most affects the concentrating photovoltaic (CPV) system performance, depending above all on the concentration factor and optical efficiency. Hence, a basic aspect is the concentrated solar flux measure on the receiving area, the evaluation of which is principally realized by indirect measurement methods. First, a literature review on indirect and direct methods used for the evaluation of concentrated solar flux and optical parameters is presented in this paper. The experimental measurement procedure, which is able to evaluate the optical parameters and concentrated solar flux in CPV systems, is also presented. The main steps of this procedure are represented by experimental system setup, sensor selection for concentrated solar flux estimation, identification of all the factors affecting optical performances, and development of an experimental campaign and output analysis. In particular, the optical characterization results of a CPV system are obtained by means of in-depth experimental analysis using Triple-Junction (TJ) solar cells with areas of 5.5 × 5.5 mm2 and 10 × 10 mm2. Three different setups have been analyzed related to primary and secondary optics composition. The main aim of this paper is the determination of a direct measuring technique, rarely adopted in literature in comparison to the established techniques, that is able to evaluate experimentally the optical parameter values and that can be standardized for other CPV systems. In particular, equations that link the optical concentration factor (C) and efficiency (ηopt) with focal distance (h) represent the fundamental results. They can be used for similar point-focus configurations presenting the same TJ cell size and ranges of C, ηopt and h. Finally, the experimental results of the direct method are compared with those of an indirect method adopting the same CPV system and operational conditions.

Cooling performance of sliver solar cells in low concentration PV system with ribbed-groove mini-channel heat sink

This paper presents a numerical investigation of a cooling system designed for concentrated photovoltaic (PV) systems. To enhance the performance of system and reduce operating temperature, mini-channels have been integrated onto the PV cells. Heat transfer improvement in these mini-channels is proposed by integrating ribbed grooves in a parallel alignment on their sidewalls. Water is used as a cooling fluid having laminar flow regime maintained within the Reynolds number between 100 and 500. The mini-channel is subjected to a constant heat flux, and various parameters, such as rib height, pitch, and angle are examined in order to assess their impact on Nusselt number, thermal resistance, temperature fluctuations, and friction factor variation. Subsequently, by identifying the optimal rib dimensions, the rib arrangement is further investigated. Results demonstrate that compared to a smooth channel, the presence of ribs reduces thermal resistance by up to 25.9 % as the Reynolds number increases. Furthermore, increasing rib height induces more vortices behind the obstacles, enhancing heat transfer between the fluid and channel walls. Additionally, by altering the rib arrangement, thermal resistance decreases significantly, with the maximum reduction of 32.14 % observed in the case of a two-blade configuration. Moreover, the integration of blades leads to a maximum 111.96 % increase in the Nusselt number compared to a smooth channel. In this context, the 2-blade and 4-blade configurations result in a maximum reduction of 6.48 K in the channel base temperature compared to the optimized ribbed mini-channel. These findings offer valuable insights into enhancing the performance of concentrated PV systems through innovative cooling strategies.

Mathematical model to optimize solar spectrum allocation for a Stirling engine-based concentrated photovoltaic thermal system

Incorporating a Stirling engine into a concentrated photovoltaic thermal system (CPVT) with spectral beam splitting converts wasted photovoltaic panel energy into electricity, boosting efficiency. However, complex Stirling engine development slows system performance estimation, which explains the scarce studies on the Stirling engine-based CPVT spectrum allocation range. Furthermore, the literature shows inconsistent remarks on low or high-energy photon allocation to a thermal system and uncertainty of solar irradiance variation effect on spectrum allocation. A generic methodology is presented for determining optimal spectrum allocation for a Stirling engine-based CPVT system with a dichroic filter. The analysis in this work shows that considering non-absorption and thermalization losses improves performance by 13.2 % compared to solely accounting for non-absorption loss in beam splitting. Additionally, a shift of up to 40 nm in the optimal spectrum allocation range is observed with a daily spectral irradiance source compared to the AM1.5D source. The PV mathematical model is validated with an average error of 8.9 %, and the Stirling engine model with an error of 5.2 %. Through this study, future researchers can determine an optimal spectrum allocation range for Stirling engine-based CPVT that maximizes PV performance based on a specified location with the proposed generalized CPVT model.

Effects of climate variables and nanofluid-based cooling on the efficiency of a liquid spectrum filter-based concentrated photovoltaic thermal system

Effects of climate variables and nanofluid-based cooling on the efficiency of a liquid spectrum filter-based concentrated photovoltaic thermal system

A multi-model approach based on CARIMA-SARIMA-GPM for assessing the impacts of climate change on concentrated photovoltaic (CPV) potential

This research paper proposes a novel multi-model approach, integrating the CARIMA-SARIMA-GPM framework, to assess the combined impacts of climate change and land use change on the potential of concentrated photovoltaic (CPV) systems. By considering both climatic variables and land use patterns, this study aims to provide a comprehensive understanding of how these factors influence CPV performance in the context of a changing environment. The proposed methodology offers valuable insights into the future viability and sustainability of CPV technology, enabling informed decision-making for policymakers, energy planners, and investors in the Middle East and Africa. As a result, the ability of the hybrid evolutionary CARIMA-SARIMA-GPM to predict the potential of CPV energy output for assessing the impacts of climate change on it was investigated in Alice Springs, the Middle East, and Africa. The outcome showed that the hybrid model significantly outperformed the other machine learning approaches. The fitted model was used to assess the potential impacts of climate change on CPV generation in Alice Springs, Australia, as well as the Middle East's and Africa's comparable climatic conditions. According to the study, climate change had the greatest impact on solar CPV energy production in Alice Springs, where it decreased the most by 8.577% under moderate forcing scenarios (SSP245) during the boreal summer season; moderately in the Middle East, where it decreased the mode by 2.316% under mitigation scenarios (SSP126) during the boreal summer season; and extremely minimally in Africa, where it decreased the mode by 1.263% under the far future sequencing period (2051–2099). Climate change also increased solar CPV energy production significantly in the Middle East in the far future sequencing period (2051–2099), as well as in Alice Springs, Australia, and Africa in the near future sequencing period (2015–2050). The strongest forcing scenario (SSP585) increased by 7.644% during the boreal autumn season in Africa; moderately increased by 6.502% during the boreal spring season in the Middle East; and had the least beneficial effects in Alice Springs, Australia, with increases of 5.538% during the boreal winter season. On an annual basis, all three regions showed a similar trend. Climate change (CLC) and urban expansion (URE) were also investigated in the Middle East and Africa for their effects on changes in solar CPV energy output. URE had a greater impact in Africa than the Middle East under the effective scenario, with a URE value of 45.45% for Africa and 20.15% for the Middle East, whereas CLC had a greater impact in the Middle East than Africa, with a CLC value of 29.01% compared to 5.47% for Africa. CLC and CPV residual factors, on the other hand, have a greater impact in the Middle East than in Africa, with effects of 29.01% and 50.83%, respectively, compared to 5.47% and 49.09%. The potential difference that drives the remediation of specific pollutants lies in the application of advanced technologies and sustainable practices. By exploring innovative solutions, such as using renewable energy sources like concentrated photovoltaic (CPV) systems, we can effectively mitigate the impacts of climate change and land use changes on pollutant concentrations. These technologies have the potential to significantly reduce pollution levels and create a cleaner and healthier environment for future generations. Assessing the CPV potential in different regions like Alice Springs, Australia, the Middle East, and Africa allows us to identify areas with high solar energy resources that can be harnessed for efficient pollutant remediation. Implementing prompt climate mitigation and adaptation measures is crucial for achieving a net-zero energy transition in the Middle East and Africa by 2050. In this context, prioritizing solar energy as the primary source of renewable energy is imperative for successful low-carbon economic planning in these regions.

Simulation for impact of nanofluid spectral splitter on efficiency of concentrated solar photovoltaic thermal system

Nanofluid filter has been applied in current research to boost the efficiency of a concentrated photovoltaic thermal (CPVT) module. Owing to tunable optical features of nanofluid and its greater thermal characteristics, it was utilized as spectral filter and cooling fluid in the present proposed solar system. The mixture of silver and water has been utilized as working fluid and its concentration within the filter and cooling duct are 0.005 and 0.05, respectively. Three dimensional models have been proposed involving spectral distribution of solar irradiation. Also, transmissivity of nanofluid filter has been derived according to empirical models. Two structures have been applied for cooling duct: 1) straight bottom wall; 2) wall with triangular obstacles (semi-wavy wall). As velocity of nanofluid within the filter (Vf) section enhances, the electrical performance increases about 3.4 %. For case 4, with augment of concentration ratio (CR) from 3 to 30, the electrical performance reduces about 13.57 % while thermal performance augments about 5.68 %. When CR=10, utilizing case 4 makes electrical and thermal performance to enhance about 25.09 % and 22.36 % in comparison to case 1. Also, cell temperature decreases about 47.82 % with applying the filter within the second structure of the cooling duct.

Thermal Management and Electrical Efficiency for Concentrator Photovoltaic Systems Using Multiple Phase Change Materials

The performance of solar panels in generating electrical energy is closely tied to the effectiveness of the employed cooling system. While the utilization of phase change materials (PCMs) as latent thermal units as a cooling system has been suggested for recovering solar panels’ heat, research focusing on a comprehensive comparison of various PCMs for this purpose has been lacking. To address this gap, our study aims to provide a thorough comparative analysis of three distinct PCMs: Gallium, Paraffin RT35HC and CaCl2.6H2O. The objective is to determine the most efficient PCM for cooling solar panels. Using Fluent-Ansys-based numerical simulations, our study investigates the transient (unsteady) thermal exchange between PCMs and a solar panel. The research examines various PCM types housed in a container behind the solar panel, while also assessing the impact of inclination angles (0° to 90°) on thermal and electrical efficiency. Our results highlight Gallium's superior cooling performance and sustained high electrical efficiency. Conversely, CaCl2.6H2O leads to decreased electrical efficiency (less cooling performance), while RT35HC shows potential at extreme angles with a slight efficiency decline (∼10.2%). By offering a comprehensive comparative assessment of diverse PCMs and considering the influence of inclination angles, our study contributes valuable insights to optimizing solar panel cooling systems and enhancing overall energy generation efficiency.

Comprehensive investigation of a building integrated crossed compound parabolic concentrator photovoltaic window system: Thermal, optical and electrical performance

Integrating PV solar cells with concentrators into window systems can not only generate electricity for a building, but also has the potential to enhance the thermal resistance of the building's windows without a significant sacrifice of light transmittance for passive daylight. A novel system, known as the crossed compound parabolic concentrator photovoltaic window, has been recently studied for its electrical properties. However, its thermal and optical performance, particularly in terms of the overall heat transfer coefficient (U-value) and total optical transmittance when integrated into a building, remains unexamined. These factors are crucial for predicting the system's impact on a building's energy efficiency and indoor comfort. Therefore, this paper aims to investigate the U-value of this window system under various temperature scenarios and the optical transmittance of the window at different incident angles. The thermal conductance was assessed through numerical simulations using a computational fluid dynamics model, which was validated by experimental measurements conducted in a large climate chamber. The optical transmittance was investigated using a validated 3D ray-tracing model. The total optical transmittance and electricity generation were calculated for typical sunny days in winter and summer under London's climate conditions. Additionally, alternative designs were developed to explore the impact of pitch between adjacent optics on the thermal conductance and optical transmittance of the window. The results showed that the window with a configuration of Dx = Dy = 5 mm (where Dx and Dy represent the horizontal and vertical pitches, respectively, between two adjacent solar optics) achieved the lowest U-value (2.566 W/m2·K). This U-value is slightly lower than that of the original window design, which has a U-value of 2.575 W/m2·K. The original window configuration with Dx = Dy = 1.77 mm produces the highest power output. Specifically, it generates 499.25 Wh/m2 on a typical sunny day in winter and 162.73 Wh/m2 on a typical sunny day in summer. However, it exhibits the lowest transmittance (14.6 % on a typical sunny day in winter and 25.2 % on a typical sunny day in summer, respectively), indicating that it is more suitable for buildings with a higher window-to-wall ratio to ensure an adequate amount of natural light. For buildings with a lower window-to-wall ratio, the CCPC-PV window should be designed with a larger horizontal pitch, such as 15 mm and 30 mm, to meet indoor illuminance requirements while also providing enhanced thermal performance and additional power output.

Effects of partial shading on thermal stress and exergetic efficiency for a high concentrator photovoltaic

Highly concentrated photovoltaic systems can produce higher energy yields than conventional photovoltaic panels but have yet to reach widespread deployment, partly because of lower lifetime and hence cost effectiveness. One limiting factor in the lifetime is the excessive generation of thermal stress. This study takes a multi-objective approach to the calibration of a highly concentrated photovoltaic thermal hybrid system. Novelty is found by exploring the relationship and trade-off between thermal stress and exergetic efficiency. A variety of optical configurations are compared by partially shading the input aperture of the primary optics. Similarly, adjustments to the receiver are made by changing the angle of the solar cell by 45°. To minimise light spillage. The primary and secondary optic positions stay the same throughout all calibrations.By experimentally validating a COMSOL model of the concentrator photovoltaic system (including irradiance distribution) a thorough analysis is conducted. It was found that the maximum thermal stress within the solar cell in this study could drop by almost 10 % with small losses (<3.5 %) to total exergetic efficiency after only small changes to receiver position. Further investigations into other specialised concentrator photovoltaics are required to understand the range of impact on thermal stress.

Performance mapping of silicon-based solar cell for efficient power generation and thermal utilization: Effect of cell encapsulation, temperature coefficient, and reference efficiency

Characteristic Performance Maps (CPMAPs) are developed for silicon-based solar cells, based on a massive parametric study implemented by a validated thermal-fluid model. These CPMAPs reveal the variation of thermal-, energy-, and exergy-related performance indicators. The studied solar cell integrated with a generic heat sink satisfies the temperature demand within safe solar concentration range. The developed sets of CPMAPs investigate the effect of cell encapsulation, temperature coefficient, and reference efficiency. Findings indicate that reducing the thermal resistance of the intermediate layers between the silicon layer and the heat sink significantly elevates the maximum allowable concentration ratio. Besides, decreasing the thermal resistance of the intermediate layers enhanced the overall exergy efficiency. Furthermore, solar cells with lower temperature coefficients exhibit a minimal impact on expanding the safe range of solar concentration. However, the CPMAPs indicate that such cells are recommended for concentrator photovoltaic systems due to their ability to mitigate the inevitable decrease in electrical efficiency associated with high temperatures under high solar concentration. The use of high-reference efficiency cells slightly expands the safe range of solar concentration and leads to higher electrical exergy efficiency, albeit at the expense of reduced thermal exergy efficiency. Low-reference efficiency cells exhibit a higher potential for combined heat and power applications due to increasing the overall exergy efficiency. In contrary, high-reference efficiency cells are found to be more suitable for power generation applications. The proposed CPMAPs have significant implications, providing a novel roadmap for future research in the quantitative selection and design of photovoltaic systems.