Concentrator Solar Cells Research Articles

Output power analysis of low concentrated solar cells with fresnel lens optics

In this work, we introduce a П-shaped LCPV which works with a simple single-axis solar tracking system. The simulation of the П-shaped LCPV was made on COMSOL Multiphysics and output power of the LCPV was modeled and compared with other PV, LCPV systems using predicted optical efficiency at different incidence angles by regression methods such as XGBoost regression, Linear Regression, Support Vector Regression, Decision Tree Regression, Random Forest Regression. The most effective one was XGBoost regression with accuracy of 91.23931 %. The П-shaped LCPV generates 2.2 times more energy than the fixed nine-solar cell panel per a day. Using nine solar cells and the designed optics allows the system to operate well at wider incidence angles using a single-axis solar tracking system which rotates the system only 4 times a day. The П-shaped LCPV is less complex and cheaper than an ordinary Fresnel lens-based LCPV.

Analysis of ultra-high concentration solar cells integrated with a confined microjet impingement cooling

The high solar concentration levels result in an intense influx of energy onto the concentrated triple-junction solar cell, leading to elevated temperatures that can degrade the cell’s performance and overall lifespan. This necessitates the development of innovative and efficient cooling strategies to mitigate temperature-induced losses and ensure optimal energy conversion. This study introduces an innovative micro jet impingement cooling system designed for ultrahigh concentrated solar cells, addressing the critical challenge of temperature management under high solar concentration levels. Furthermore, structural modifications were proposed, including reducing ceramic layer thickness to decrease the thermal resistance and using thermal interface materials to improve the cell temperature uniformity. A three-dimensional computational fluid dynamics model was developed to evaluate the proposed system’s performance and compare it with the traditional jet impingement heat sink. The model was verified and validated using empirical data in the literature. In addition, the Response Surface Method was employed to provide a comprehensive understanding of the system’s behavior under various weather conditions and cooling fluid effects. The results showed that concentration ratio and direct normal irradiance significantly affect the system’s performance. Moreover, the new cooling system maintains temperatures below the recommended operating temperature. Finally, the environmental assessment indicated substantial energy payback time reductions at 20,000 Suns, which is significantly lower than at 1000 Suns. The CO2 emissions analysis shows a marked potential for emissions mitigation, particularly at higher CRs and longer sunshine hours. These insights offer a comprehensive overview of ultrahigh concentrated solar cell thermal system performance, highlighting its efficiency and environmental sustainability in solar energy applications.

4E experimental investigation of concentrated solar cell cooling via system of heat dissipator-phase change material

Low-concentrator solar cell (SC) experimentally cooled using a new composite thermal regulation system of heat dissipator (HD) and phase change material (PCM) is investigated. The impact of area ratio (AR; HD area/SC area) of 1.5 and 2 at different HD thicknesses (h) on the system performance is reported. An energy, exergy, economic, and enviroeconomic assessments for the different cooling systems used for the SC thermal regulation are presented. The results show that the SC temperature reduction increases with increasing the HD thickness and AR. Compared with reference SC, SC-PCM/HD (AR=2/h = 3) achieves a maximum temperature reduction of 24 °C compared with 9.1 °C and 21.8 °C for SC-PCM and SC-HD, respectively. Moreover, SC-PCM/HD cooling system achieves the maximum enhancement in the average electrical efficiency and power output of 11.88 % and 12 %, respectively, compared with reference SC. The PCM thermal energy storage rate and PV system efficiency increase with increasing area ratio and decreasing the HD thickness. Using HD of (AR=2/h = 1) in conjunction with PCM yields the most favorable PCM thermal performance where it enhances the thermal energy storage, rate of energy storage, and overall thermal system efficiency by 9.5 %, 40 %, and 20.36 %, respectively, compared with using PCM only. Moreover, the PCM/HD cooling system is more economical than using PCM or HD only, and reference SC, with a maximum cost saving of 41.7 % compared with reference SC. The SC-PCM/HD cooling system is the most eco-friendly option with net CO2 mitigation and ψCO2 of 146.2 kg and 5.84$, respectively compared with 143.7 kg and 5.74$, respectively for SC-PCM.

Experimentally thermal management of low-concentrated photovoltaic via new configurations of dimple/trapezoidal heat spreaders of different sizes

ABSTRACT This study experimentally investigates the influence of dimple (DHS), flat plate (FHS), and trapezoidal heat spreader (THS) cooling systems on thermal regulation of low concentrated solar cell (LCPV). It is performed at 1.5 and 2 HS/PV area ratio and HS thicknesses 1 and 2 cm under 3100 W/m2 solar irradiance. Results reveal that using DHS outperforms other cooling systems in terms of cell temperature and electric performance. Increasing HS area ratio and thickness significantly enhances PV performance. DHS, PHS, and THS achieve maximum PV temperature reduction of 44.4, 43.2, and 41°C and PV efficiency improvement of 16.89%, 14.87%, and 13.9%, respectively.

Fabrication of high-performance lens arrays for micro-concentrator photovoltaics using ultraviolet imprinting

Micro-concentrator photovoltaics (micro-CPV) is a cutting-edge CPV approach aimed at increasing the efficiency and reducing the cost and carbon footprint of solar electricity by downscaling concentrator solar cells and optics. The reduced size of micro-CPV provides several advantages over conventional CPV, including shorter optical paths and lower temperature and resistive losses in the cell, resulting in higher electrical efficiencies. This may increase the energy yield per area compared to conventional CPV or silicon modules. Cost reduction is achieved through material savings and the use of continuous manufacturing methods enabled by the tiny size of cells and optics, such as roll-to-roll (R2R) and roll-to-plate (R2P) ultraviolet (UV) imprinting for optics production. However, adapting these processes to large-area arrays of Fresnel micro-lenses with no wasted areas and high efficiency remains a challenge. In this study, we present a comprehensive methodology for the development of micro-CPV optics with full area coverage—from design and mastering to up-scaling, tooling, and replication. The methodology involves designing a non-rotationally symmetric elementary insert tailored to ultraviolet imprinting. Crucially, multiple inserts are originated via precision machining and recombined to form a single array master mold without wasted areas. The master is then replicated into a flexible working stamp for UV imprinting of Fresnel lens arrays, utilizing different UV curable materials. The functional characterization of the lenses demonstrates an optical efficiency of 80% at 178X under collimated white light, representing the highest effective concentration achieved using UV-imprinted Fresnel lenses. Furthermore, initial reliability tests confirm the absence of degradation during thermal cycling or outdoor exposure. This methodology paves the way for continuous high-throughput manufacturing of micro-lens arrays using R2R or R2P methods, presenting a significant step forward in micro-CPV.

Solar concentrators filled with liquid for enhancement of photocurrent generation and angular responses of light incidence

Design and manufacturing of solar concentrator materials and structures for external light trapping have been widely explored for decades to enhance solar cell performances in various photovoltaic (PV) devices such as silicon, organic, and perovskite ones. Among them, remarkable progress in development of the concentrators has been made to improve the solar concentration ratio of power conversion efficiency (PCE). However, only some studies were carried out to enhance the angular responses of light incidence (AOI). This paper reports a simple liquid-filled solar concentrator (LFSC) that can be effectively implemented by incorporating optical reflection with total internal refraction (TIR). Using the fused deposition modeling (FDM) method in the 3D printing process, the hollow compound concentrators in a parabolic shape were efficiently produced at a low cost. With liquid water and silicone oil, the simulation and experimental results illustrated that the PCE and AOI were increased for the concentrator solar cells composed of bulk heterojunction structure. In particular, it was found that all the AOI exhibited an exponential decay as a Gaussian distribution. Hence, it provided the capability of control over concentrator material and geometry in design and fabrication. In this manner, various such simple devices fabricated by the present method can be further applied in future applications such as PV cell modules and systems.

Parabolic Mirror‐Assisted Thermoelectric and Radiative Cooling System for Maximizing Power Generation Utilizing Solar and Outer Space Thermodynamic Resources

AbstractRadiative cooling technology is extensively researched as a green technology, leveraging outer space as a thermodynamic resource. Recently, integrating thermoelectric generators (TEGs) and radiative coolers (RCs) are proposed to generate power using the temperature difference between the ambient and the radiative cooler. However, current TEG‐RC systems only utilize one thermodynamic resource, resulting in suboptimal efficiency. It proposes a parabolic mirror‐assisted TEG‐RC system that fully utilizes both the Sun and outer space as thermodynamic resources. The system places the hot side of the TEG, covered by a solar absorber (SA), at the focal point of the parabolic mirror, while the RC is located on the cold side of the TEG. Theoretical and experimental results reveal the optimal ratio between the RC and SA sizes to balance the power mismatch between cooling and heating powers. It also finds that the number of TEG stacks significantly affects power generation efficiency and determines the optimal number. Outdoor measurements demonstrate exceptional power generation during the daytime, which is an unprecedented achievement. This study also demonstrates the further enhancement in power generation efficiency when the proposed system is integrated with concentrated solar cells instead of the SA.

Swirling jet impingements for thermal management of high concentrator solar cells using nanofluids

Large intensity of irradiance in high concentrator solar cells leads to extremely high temperatures causing an adverse effect on the performance of solar cells. Efficient cooling systems are crucial for the optimal performance of high concentrator cells, which are typically required to operate within a prescribed temperature range (⁓ 110 °C). The implementation of effective cooling strategies poses a significant challenge for High Concentrator Photovoltaic Thermal (HCPV/T) hybrid systems to ensure sustained performance and longevity of the modules. This study proposes a novel method for the thermal management of High Concentrator Solar Cells (HCSC) using swirling nanofluid jets impinging on a heat sink. The study applies RANS (Reynolds-Averaged Navier-Stokes) method with the SST k-ω turbulence model and energy equation to resolve a conjugate heat transfer analysis for three different flow ratios: Qr = 0, Qr = 0.5 and Qr = 1 and two water-based nanofluids: Al2O3-Water and CuO-Water. The numerical results demonstrate a significant decrease in cell temperatures, reaching as low as 71 °C. At a mass flow rate of 50 g/min, the use of Al2O3-Water nanofluid increases the overall electrical efficiency by a maximum of 39.43%. In contrast, a minimum electrical efficiency of 39% for CuO-Water nanofluid is obtained for a lower mass flow rate (25 g/min). Al2O3-Water nanofluid yielded a maximum PEC (Performance Evaluation Criteria) of 116%, while CuO-Water nanofluid yielded about 113%. In addition, an increase of the mass flow rate results in an improvement of temperature uniformity, as demonstrated by a reduction of temperature variation from 6.8 to 5.2. These results suggest that the use of nanofluids is promising. The proposed swirling jet impinging on a heat sink in combination with nanofluid provides an effective cooling technique for HCSC, thereby potentially contributing to the improvement of the cell's performance and longevity.

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.

Evaluation of Power Performance of Solar Module Using Two Diode Model with MATLAB Simulation

This paper tries to represent the difference between single diode and two diode photovoltaic models in terms of efficiency simulated by MATLAB. The research activities done earlier had shown a clear preview that the solar cell can act as concentrated solar cell for increasing the conversion efficiency to a great extant so that output power can be improved to a large scale. Here for showing the manner of concentrated solar action double diode model has been calculated for observing the power difference in comparison with the solar cell of single diode as a convenient one. It has been observed that the photovoltaic module with two diode model is observed as highly efficient in comparison with single diode model. And this two diode model can be treated as highly efficient to convert the solar energy in the electric energy. Also, the behavior of power performance is observed practically which is included in this paper. And finally, a comparison has been drawn out to exhibit the verification of power performance for two diode model using MATLAB simulation. The mostly impact factors considered in this paper are solar irradiance and temperature affecting the power output from PV module.

Diffuse optical properties of a Fresnel lens sunlight concentrator.

A combined module that combines a concentrator with planar photovoltaic circuits provides energy conversion of both parts of global terrestrial radiation: direct sunlight by concentrator solar cells and scattered (diffuse) sunlight by planar (non-concentrator) photoconverters. The decrease in Fresnel lens concentrating ability is usually associated with imperfections in the optical refractive surfaces, where some part of the direct light, which arrives normal to the surface of the Fresnel lens and is intended to be concentrated, becomes scattered and directed off the highly efficient concentrator solar cell. The diffuse light flux propagates inside the volume of the combined photovoltaic module. This flux undergoes multiple reflections from the structural elements, is partially absorbed, and ultimately reaches the photoconverters of the planar circuit. Thus, two types of diffuse light impinge the planar circuit: "external" from the atmosphere and "internal" produced by the Fresnel lens from direct light. This Letter proposes a method for determining the diffuse properties of sunlight concentrators such as Fresnel lens.

Improved Performance of Silicon-Germanium Solar Cell Based on Optimization of Layer Thickness

Electrical energy has become an essential part of our life. Therefore, its supply must be sustainable, economical, and environment-friendly. The conversion of sunlight into electricity is made possible through the solar cell, a semiconductor device, however, the conversion efficiency of these cells is low which can be further improved. This research work presents the design and performance analysis of silicon-germanium (Si-Ge) solar cells. Amorphous silicon / crystalline silicon Heterojunction (a-Si/c-Si HIT) solar, Ge, Si-Ge alloy with 25% Si concentration solar cells are designed in Afors-Het software. An improved conversion efficiency (?) of 25.23%, 5.125%, and 11.53%, respectively is achieved.

PMMA Lens Arrays for Micro Concentrator Solar Cells Produced by Hot Embossing

The rising energetical needs of modern society have been increasingly pushing for the improvement in energy efficiency. Thin-film solar cell technology encompasses several types of devices whose purpose is to gather energy emitted from a luminous source and convert it into usable electrical energy for a variety of applications, particularly low-powered devices. Micro concentrator solar cells are promising devices to solve the materials availability problem and address the power conversion efficiency simultaneously. Since the energy conversion efficiency for this type of solar cell is not particularly high, it stands out to benefit greatly from using an optical concentrator element to increase the light intensity reaching the active surface. The micro-concentrator element is comprised of a micro-lens array, which can be manufactured by different technologies, such as polymer injection moulding, extrusion, or hot embossing. In this work, we explore how hot embossing can be used to inexpensively produce spherical lenses with Ø 1 mm in an array according to micro concentrator solar cell requirements. A simple compression system coupled with an infrared lamp heat chamber was used to emboss PMMA disks. Different mould insert manufacturing technologies were used and different hot embossing parameters were assessed. The process replicability of the micro-lens cavities was determined by infinite focus microscopy and optical microscopy. The most promising lens array was achieved with a mould insert produced by μ-EDM (with Ra and Rz values of 0.6 μm and 4.58 μm, respectively).

Electrification of Africa through CPV installations in small-scale industrial applications: Energetic, economic, and environmental analysis

This paper aims to evaluate the energetic, economic, and environmental performances of small-scale concentrated photovoltaics (CPV) power systems under 107 African climatic and financial zones with different energy mixes. The proposed concept focuses on small-scale installations for small- or medium-scale industrial premises as such devices are involved in the international strategy about micro-grids. Yearly average electric productions, capacity factors, economic and environmental considerations, and sensitivity were all analysed. The mathematical methodology for calculating the power of a concentrated triple-junction solar cell, the annual energy conversion of a CPV plant, the costs, and the CO2 mitigation were assessed.The parametric study shows that the capacity factor becomes highest for a cell area of 5.5 cm2 or if the concentration ratio reaches the value of 2400. Furthermore, LCOE is lowest for Errachidia in Morocco with 15.88 c$/kWh followed by Fada in Chad with 16.82 c$/kWh, while it is highest in Wad Hajm in Sudan as 5.23 × 1016 c$/kWh. Moreover, South Africa allows the highest reduction of indirect CO2 emissions. Furthermore, energy produced is greatest in Errachidia in Morocco (606.27 GWh), Tiaret in Tunisia (601.11 GWh), and Upington in South Africa (598.11 GWh). Results are shown on innovative GIS maps of Africa.

Dependence of the vertical‐tunnel‐junction GaAs solar cell on concentration and temperature

Modelling the current–voltage (I–V) characteristics of photovoltaic (PV) devices is important for understanding their behaviour and potential. Typically, the single exponential model (SEM) is used because of its simplicity and accuracy. In this work, we validate the SEM for a gallium arsenide (GaAs) vertical-tunnel-junction (VTJ) using TCAD software. This cell is the key to overcoming the series resistance limitations of current concentrator solar cells, which can lead to the development of ultra-high concentrator photovoltaic systems (UHCPV) with concentrations (Cratio) greater than 1000 suns. The results indicate that the SEM is a suitable tool to model the I–V characteristics of the VTJ cell with mean errors lower than 1%. Moreover, the solar cell did not show any limitations regarding the Cratio and temperatures under investigation. In addition, the analysis of the temperature coefficients of the cell demonstrates that their dependency on temperature reduces as Cratio increases. The results of this work suggest that VTJ is a promising solution to produce a new generation of high-efficiency and low-cost UHCPV systems.

Assessment of a novel multi-generation solar CPV/T system combining adsorption and organic rankine cycle subsystems

Renewable energy based multi-output hybrid systems have a great potential to augment the energy utilization efficiency. In this study, performance evaluation of a concentrated photovoltaic thermal (CPV/T) system coupled with an integrated adsorption-Organic Rankine Cycle (ORC) system is introduced in which different integration options to produce power, cooling, heating, and desalinated water are mathematically investigated and experimentally validated. The evaporator of the adsorption heat pump is coupled with the condenser of the ORC in order to lower the temperature at which heat is rejected in the ORC leading to higher ORC thermodynamic efficiency. CPV/T using a Fresnel concentrator and multi-junction solar cells with different homogenizer types is investigated to produce electricity and thermal energy at the highest possible temperature that can be used to drive the adsorption system (AD) and ORC. By using antireflective coating in the refractive homogenizer, the optical efficiency is increased to 87.5%. Results showed (i) maximum overall efficiency of 68.47% can be achieved at evaporation temperature of 15 °C in the AD system and (ii) the integrated system can provide electricity of 13.08 kW, potable water of 79.17L/day, cooling power of 2.06 kW or heating power of 0.8 kW using only 38.4 m2 of surface area.

Light concentration solar cell: temperature proper and dynamic effects on electrical parameters determined by using J-V and P-V characteristics

The solar cell is assumed to be under light concentration (C=50 Suns) which leads us to take into consideration the electric field induced by electrons concentration gradient. We also take into consideration temperature influence on electron and hole diffusion parameters, on carrier generation rate, on carrier intrinsic concentration and on silicon energy gap. It emerges from results analysis that increase in temperature leads to decrease of open-circuit voltage and the photovoltaic parameters at the maximum power point (MPP) such as electric power, photo-voltage and photocurrent with however a slight increase of short-circuit photocurrent density. It also appears that temperature has a double effect on electrical parameters. The temperature dynamic effect which is characterized by parameters variations linked to operating point displacement caused by temperature variations. And the temperature proper effect which is characterized by parameters variation with temperature at a given operating point. Thus, the combination of these two effects represents temperature effective effect.

Concentrated thermionic solar cells using graphene as the collector: theoretical efficiency limit and design rules

We propose an updated design on concentrated thermionic emission solar cells, which demonstrates a high solar-to-electricity energy conversion efficiency larger than 10% under 600 suns, by harnessing the exceptional electrical, thermal, and radiative properties of the graphene as a collector electrode. By constructing an analytical model that explicitly takes into account the non-Richardson behavior of the thermionic emission current from graphene, space charge effect in vacuum gap, and the various irreversible energy losses within the subcomponents, we perform detailed characterizations on the conversion efficiency limit and parametric optimum design of the proposed system. Under 800 suns, a maximum efficiency of 12.8% has been revealed, where current density is 3.87 A cm−2, output voltage is 1.76 V, emitter temperature is 1707 K, and collector temperature is 352 K. Moreover, we systematically compare the peak efficiencies of various configurations combining diamond or graphene, and show that utilizing diamond films as an emitter and graphene as a collector offers the highest conversion efficiency, thus revealing the important role of graphene in achieving high-performance thermionic emission solar cells. This work thus opens up new avenues to advance the efficiency limit of thermionic solar energy conversion and the development of next-generation novel-nanomaterial-based solar energy harvesting technology.

Layered Dion-Jacobson-Type Chalcogenide Perovskite CsLaM2X7 (M = Ta/Nb; X = S/Se) with a Narrow Band Gap of ∼1 eV as a Promising Rear Cell for All-Perovskite Tandem Solar Cells.

Perovskite-perovskite tandem solar cells have bright prospects to improve the power conversion efficiency (PCE) beyond the Shockley-Queisser (SQ) limit of single-junction solar cells. The star lead-based halide perovskites are well-recognized as suitable candidates for the front cell, thanks to their suitable band gap (∼1.8 eV), strong optical absorption, and high certified PCE. However, the toxicity of lead for the front cell and the lack of a narrow band gap (∼1.1 eV) for the rear cell seriously restrict the development of the two-junction tandem cell. To break through this bottleneck, a novel Dion-Jacobson (DJ)-type (n = 2) chalcogenide perovskite CsLaM2X7 (M = Ta, Nb; X = S, Se) has been found based on the powerful first-principles and advanced many-body perturbation GW calculations. Their excellent electronic, transport, and optical properties can be summarized as follows. (1) They are stable and environmentally friendly lead-free materials. (2) The direct band gap of CsLaTa2Se7 (0.96-1.10 eV) is much smaller than those of lead-based halide perovskites and very suitable for the rear cell in the two-junction tandem cell. (3) The carrier mobility in CsLaTa2Se7 reaches 1.6 × 103 cm2 V-1 s-1 at room temperature. (4) The absorption coefficients (3-5 × 105 cm-1) are 1 order higher than that of Si (104 cm-1). (5) The estimated PCEs of the Cs2Sb2Br8-CsLaTa2Se7 tandem cell (33.3%) and the concentrator solar cell (35.8% in 100 suns) are higher than those of the best recorded GaAs-Si tandem cell (32.8%) and the perovskite-perovskite tandem solar cell (24.8%). These energetic results strongly demonstrate that the novel lead-free chalcogenide perovskites CsLaM2X7 are good candidates for the rear cell of tandem cells.

A concentrated solar spectrum splitting photovoltaic cell-thermoelectric refrigerators combined system: Definition, combined system properties and performance evaluation

Currently, a concentrated solar spectrum splitting photovoltaic cell driven semiconductor thermoelectric refrigerator has no relevant report. In this work, a new style model of the concentrated solar spectrum splitting photovoltaic cell-thermoelectric refrigerators (CSSPV-TERs) combined system is established. On the basis of numerical calculation and theoretical study in detail, the influences of the critical parameters on the property of the CSSPV-TERs combined system are analyzed and evaluated. The total efficiency of the CSSPV-TERs combined system is 23.4%. Meanwhile, the current density J, structural factor c and numbers of thermoelectric devices N has been optimally selected to obtain the best COP. The three critical optimal parameters, N = 7, J = 11.7 A/cm2, and c = 0.000125 cm−1, of the CSSPV-TERs combined system can be obtained, which cause the maximum COP, i.e., COPmax = 0.078. The maximum COP and total efficiency of the CSSPV-TERs combined system are superior to other thermoelectric refrigeration combined systems. The research results and new model not only can provide a valuable reference and theoretical support for the optimal design of the novel solar cell driven thermoelectric refrigeration system, but also improve the conversion efficiency of the combined system by efficiently utilizing full-spectrum solar energy.