Concentrator Photovoltaic Research Articles

Forecasting solar-to-hydrogen and solar-to-methane energy conversion efficiency using Si and IMM PV-modules: A case-study in Japan

The solar-to-gas (StG) conversion system is a potential pathway for accelerating zero-carbon energy sources. In our previous study, outdoor StG conversion was accomplished using triple-junction concentrator photovoltaic (CPV) modules. The system achieved the highest performance with sets of DC/DC converters and electrochemical (EC) cells. Therefore, we aimed to investigate the prospective StG conversion from PV systems if such a system is installed in Japan. A power generation prediction model considering all weather conditions, called the Miyazaki Spectrum to Energy (MS2E), has been developed using the METPV-11 meteorological database at the University of Miyazaki. Accordingly, the amount of energy generated by various PV systems could be forecasted nationwide from the global irradiance data. In this study, we applied the MS2E PV energy prediction method and approached the potential StG conversion efficiency of silicon (Si) PV and inverted metamorphic (IMM) PV systems across Japan. Based on the actual StG measurement data, we approximated the conversion of each subsystem. The simulation results show that IMM modules can provide higher StG conversion than Si modules.

Investigation of the feasibility and potential use of sun tracking solutions for concentrated photovoltaic Case study Fez Morocco

This paper investigates the requirements, the feasibility and reliability of concentrator photovoltaic (CPV) with trackers in Fez city (Morocco) climate. In a first step, an appropriate sun tracker for a CPV prototype is design-simulated and then, based on finite element analysis, the effect of wind velocity distribution induced charge on the global structure (tracker and CPV module) is investigated for several elevation angle of the CPV unit. For all the investigated configurations, the maximum simulated misalignment still negligible, and is estimated to 4.6 × 10−6°, for a wind speed of 3.3 m/s. As a result, it is anticipated that the examined high CPV system (HCPV) will works safely under these effects. In a second step, using a home-developed Python code, and geometrical solar equations, calculations have been performed to estimate the diffuse, the direct and the global irradiations in this location. Ultimately, the energy performance of the system using System Advisor Model (SAM) software is carried out and compared to some on site real measurements. This simulation process led to a rigorous evaluation of the potential energy production with a tracked CPV panel, proving its viability in Fez Morocco. It also shows the level of accuracy of at least 0.5° that sun-tracking photovoltaic systems are necessary to maintain the least amount of power yield loss, especially for CPV facilities. This research will also serve as a valuable guide for the future sun-tracking CPV system.

Performance analysis of a ball lens as secondary optical element for a micro photovoltaic concentrator

Concentrated Photovoltaic (CPV) is a promising technology for higher efficiency power generation than other photovoltaic power generating technologies. However, the lack of demand and its failure in the commercial field is mainly due to its long-term reliability issues as well as its cost, which is an order of magnitude higher than the other technologies. Therefore, several measures have been taken to minimize the cost, improve the reliability as well as improve the performance of these concentrators. In this approach, Micro photovoltaic concentrators have been introduced as an outstanding alternative to shed light on all these challenges while keeping the same principle as the CPV modules. This paper presents a theoretical analysis of a micro photovoltaic concentrator system with a geometrical concentration ratio of 100x consisting of a Plano-convex lens as a primary optical element, a ball lens as a secondary optical element, and a solar cell. The aim is to present a compact module with high optical efficiency, low thermal stress, and high mechanical tolerance to keep the optimum optical alignment between the submillimeter cell and the small-sized optics.

Performance Enhancement of Luminescent Solar Concentrator by using Mixing Fluorescent Colors and Nanoparticles

Liquid zinc acetate nanoparticles were added to a fluorescent organic dye (fluorescein sodium) to prepare three concentrations (2 × 10-5, 7×10-5, 1×10-4) moI/L, and the absorbance of the dye was measured before and after adding Liquid nanomaterial by using two devices (SCINCO Mega-2100 UV/visible Spectrophotometer.) as well as measuring the flux of the dye before and after adding zinc acetate nanoparticles using the (Spectrofluorometer F96 PRO). The Stoke displacement (Δη), the radiative age (τfm), the fluorescence lifetime (τf), and the quantitative efficiency (Qfm) were calculated. Absorption and fluorescence curves were drawn using the Excel program. The MATLAB program was also used to measure the area under the absorption and fluorescence spectra curves. It was found that the fluorescence intensity of fluorescein sodium dye has increased compared to the intensity of fluorescence before adding the nanomaterial and thus increasing the quantitative efficiency, which in turn helps in improving the performance of the photovoltaic concentrator, resulting in an improvement in the efficiency of the solar cell.

Heat Management Strategy for All‐Inorganic, Full‐Spectral Concentrator CsPbBr3/Bi2Te3‐Integrated Solar Cells

A solution to breaking through the Shockley–Queisser efficiency limit of solar cells is to increase the irradiation intensity beyond one standard sun by means of fabricating concentrator photovoltaics (CPVs). Herein, it is demonstrated that the power conversion efficiency (PCE) of carbon‐electrode, all‐inorganic CsPbBr3 perovskite solar cell (PSC) can be enhanced to 10.08% under 5 suns from 8.94% under one sun. The efficiency improvement mainly contributes to the especially boosted open‐circuit voltage (Voc) up to 1.643 V, which is delivered by the high‐irradiation enlarged quasi‐Fermi‐level splitting in CsPbBr3 perovskite film. The substantially detrimental heat induced by carbon electrode owing to its full‐spectral absorbance to light is further used by integrating a Bi2Te3 thermoelectric generator (TEG) into this all‐inorganic CsPbBr3 PSC to play the role of refrigerant under concentrated light condition. The CsPbBr3/Bi2Te3‐integrated device achieves a PCE of 12.46% with an ultrahigh Voc of 2.114 V by the photovoltaic–thermoelectric principle. More importantly, the integrated solar cell maintains over 90% of the initial efficiency after 150 h irradiation under 5 suns, suggesting a great potential to enhance efficiency by fabricating integrated perovskite/thermoelectric devices.

Effect of Solar Cell Temperature on The Performance of Compound Parabolic Solar PV Concentrator

In this paper, a concentrating photovoltaic system (CPV) by using a compound parabolic concentrator and a monocrystalline solar module has been designed and studied theoretically under a concentration ratio of 3.16x. The performance the system is studied over the course of the day from 8:00 AM to 16:00 PM for 12 months under Iraq-Baghdad conditions. Current in a short circuit (Isc), voltage in an open circuit (Voc) as well as maximum power (Pm) are calculated with and without a concentrator under constant solar module temperature (25°C). The results indicated that the optimum value of output power can be obtained on June 21, which is about 246.9W for CPV. In the second part, the effect of solar cell temperature within a range of 25 °C−115 °C on its performance has been studied for the optimum day of the year, June 21st. The output power of the device may be viewed in CPV is 246.9 W in comparison to the flat PV module, which gives 83.44W under solar cell temperature of 25°C and decreases to 125.3W and 40W under cell temperature of 115°C for the CPV and flat module, 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.

Optimal design principle of a cascading solar photovoltaic system with concentrating spectrum splitting and reshaping

In this paper, an optimal design method and principle of a cascading solar photovoltaic (PV) system with concentrating spectrum splitting and reshaping is proposed. The cascading solar PV system uses a second thermophotovoltaic (TPV) subsystem to reshape the spectrum which cannot be efficiently used by first PV subsystem for reuse to realize cascading solar energy utilization of full spectrum. The method optimizes the solar energy distribution and TPV key component in the PV-TPV system for the first time. Through the optimal design method, the system parameters such as the optimal cutoff wavelength of the spectral splitter and the optimal absorptivity of the TPV absorber are obtained. At the same time, the specific effects of cutoff wavelength of the spectral splitter, TPV intermediate area ratio, system concentration ratio, TPV absorber and PV cell area ratio, cooling system heat transfer coefficient, and different TPV cells on the hybrid system are analyzed. At 1000 concentration ratios, the hybrid system achieves an electrical efficiency of 35.69%, which is 9.55% points higher than single PV system. The system also has efficiency and economic advantages over other concentrating hybrid systems. This paper provides guidance for the subsequent design and construction of the PV-TPV hybrid system.

Recent progresses and challenges in cooling techniques of concentrated photovoltaic thermal system: A review with special treatment on phase change materials (PCMs) based cooling

Concentrated Photovoltaic (CPV) system is one of the efficient and economical photovoltaics (PV) technologies. The fundamental principle of using CPV system is a substitution of expensive cell area with inexpensive optics. Concentrating the solar radiation on small areas enhances the power output. However, operating at high temperatures can potentially impair their life span and performance. Thus, cooling medium plays a crucial role in refining the CPV system's efficiency. The integration of the CPV system with Phase change materials (PCMs) provides a state-of-the-art hybrid design for both thermal and electrical outputs, suggesting a better utilization of solar energy. Nano-enhanced Phase Change Materials (NePCMs) were demonstrated to be the best combination for optimal behavior, such as storing and releasing energy quicker during the phase transition process without help from external systems. Key objective of this review article is to present the latest works and technical challenges on the application of PCMs and NePCMs in Concentrated Photovoltaic Thermal (CPVT) as cooling and thermal energy storage mediums to improve PV cell efficiency. This review leads to the current gaps in the research and recommends future work on developing new PCMs, and NePCMs integrated CPV systems for improved performance, life span and economic feasibility. • Different active and passive cooling techniques of CPVT systems are presented. • Thermal regulation of PCM integrated with CPVT system are extensively analyzed. • Thermal regulation of NePCMs integrated CPVT systems are discussed. • Technical challenges associated with PCM integrated CPVT systems are discussed.

High performance p++-AlGaAs/n++-InGaP tunnel junctions for ultra-high concentration photovoltaics.

A p++-AlGaAs: C/n++-InGaP: Te tunnel junction with a record peak tunneling current density of 5518 A/cm2 was developed. This was achieved by inserting a 6.6 Å undoped GaAs quantum well at the junction interface, and the numerical model demonstrated that trap-assisted tunneling contributes to the high peak tunneling current. Furthermore, we found that the p++-AlGaAs: C/n++-InGaP: Si + Te tunnel junctions have lower resistance and better stability than p++-AlGaAs: C/n++-InGaP: Te tunnel junctions in the operating temperature range of the multijunction solar cells, and the peak tunneling current density of the p++-AlGaAs: C/n++-InGaP: Si + Te tunnel junctions excess 3000 A/cm2 with a voltage drop of 7.5 mV at 10000 suns.

Performance assessment of a novel integrated concentrator photovoltaic system with encapsulated phase change materials

The utilization of phase change materials (PCMs) with concentrator photovoltaic (CPV) systems for energy storage and thermal management is limited. This is mainly due to the low thermal conductivity and poor heat transfer from the CPV cell to the PCM. In the current study, a novel design of encapsulated phase change materials integrated with a concentrator photovoltaic system is developed to enhance the conversion and thermal efficiencies of CPV systems. The new design enhances the effective thermal conductivity of the PCM-based heat sink and allows for rapid heat dissipation from the CPV cell. Two different sets of PCM enclosures are considered and compared to a conventional heat sink without encapsulation. The first set includes single, double, and triple encapsulated PCMs. The second set consists of four enclosures, each with three capsules having a combination of PCM arrangements with different melting temperatures. To assess system performance, a two-dimensional model of photovoltaic layers integrated with encapsulated phase change material-based heat sink is developed. The model is numerically simulated and validated with experimental and numerical data. Results indicate that triple encapsulation reduces the average cell temperature by 16 ℃ and non-uniformity index by 24 ℃, compared to the conventional heat sink. In addition, using triple-encapsulation results in higher electrical output power, thermal energy storage, and lower heat loss. Moreover, the system's cumulative electrical and thermal efficiency is enhanced by 21.3 % and 5.29 %, respectively. The findings introduce a more efficient design that can accommodate a worldwide increase in energy demand.

Realizing High Photovoltaic Power Densities With Tracking-Integrated Concentrator Photovoltaics

Concentrating photovoltaics (CPV) have long been held up as a solution to low power density in photovoltaics, but due to the requirement of sun tracking have been largely unable to realize high power densities in practically useful settings. The emerging concept of tracking-integrated CPV, in which the sun tracking apparatus is incorporated into the module itself, has the potential to finally achieve this goal by allowing CPV use in building integrated or rooftop settings. In this article, we will provide a status update on TI-CPV and an evaluation of its technical and economic potential with focus on diffuse light collection. We will seek to demonstrate how TI-CPV concepts that are now nearing commercialization are viable to offer, for the first time, the chance for CPV to actually deliver high power densities and high-efficiency utilization of the solar resource in practical settings such that it represents one of the best prospects for CPV to finally gain a foothold in large commercial markets. We identify TI-CPV designs with integrated mechanical tracking and diffuse light transmittance as the closest at resent to commercial feasibility, as the transmitted light offers a potential valuable secondary output. A semi-empirical performance model of such a system yields an annual electrical output of >300 kWh/m2 and 59.4 million lux-hours optical output that are equivalent to 593.4 kWh/m2 if that light would otherwise be provided by LED lamps with 100 lumen/W luminous efficacy. This would indicate that full-system capex of up to $1,600/kW could be viable relative to conventional rooftop PV systems, providing a benchmark for future manufacturing and design improvements.

Experimental and numerical study of low concentration and water-cooling effect on PV module performance

In this study, experimental and numerical examinations of the performance of the conventional photovoltaic panel, concentrated photovoltaic (CPV) system and water-cooled CPV system were performed. The tests are conducted under the climatic conditions of the city of Duhok, North of Iraq, on a sunny day on September 25, 2019. During the experiments, the average ambient temperature and average solar radiation were 32.6 °C and 930 W/m 2 , respectively. As well, MATLAB/Simulink modeling is developed by using PV module equations and the manufacturing data sheet. The empirical results showed that the ultimate panel temperature of the PV panel, concentrated PV system and water-cooled concentrated PV system is 57.5, 64.1 and 36.5 °C, respectively. In addition, the power output of the water-cooled CPV system and CPV system was improved respectively by 24.4% (effective 23%) and 10.65%. In addition, electrical efficiency was increased from 14.2% to 17% by using reflectors and water cooling with the PV panel. In the case of the water-cooled CPV system, open circuit voltage and short circuit current were increased by 9% and 5.2%, respectively. Moreover, the comparison between the experimental and numerical results agrees well.

Solar energy technology and its roles in sustainable development

AbstractSolar energy is environmentally friendly technology, a great energy supply and one of the most significant renewable and green energy sources. It plays a substantial role in achieving sustainable development energy solutions. Therefore, the massive amount of solar energy attainable daily makes it a very attractive resource for generating electricity. Both technologies, applications of concentrated solar power or solar photovoltaics, are always under continuous development to fulfil our energy needs. Hence, a large installed capacity of solar energy applications worldwide, in the same context, supports the energy sector and meets the employment market to gain sufficient development. This paper highlights solar energy applications and their role in sustainable development and considers renewable energy’s overall employment potential. Thus, it provides insights and analysis on solar energy sustainability, including environmental and economic development. Furthermore, it has identified the contributions of solar energy applications in sustainable development by providing energy needs, creating jobs opportunities and enhancing environmental protection. Finally, the perspective of solar energy technology is drawn up in the application of the energy sector and affords a vision of future development in this domain.

Experimental and Theoretical Modelling of Concentrating Photovoltaic Thermal System with Ge-Based Multi-Junction Solar Cells

Climate change is one of the biggest environmental, political, economic, technological, and social challenges of the 21st century. Due to ever-increasing fossil fuels costs. The world energy system should be transitioned to renewable energy sources to mitigate greenhouse gas emissions. Solar energy is one of the suitable alternatives to fossil fuel usage. Currently, the most widely available solar technologies are solar photovoltaic (PV) and solar thermal. The integration of these two techniques enables the exploitation of the most significant amount of solar radiation. This combination has led to a hybrid photovoltaic/thermal system (PV/T). Concentrated solar radiation on PV cells, known as concentrated photovoltaic (CPV), effectively decreases PV receivers’ area and harnesses the same quantity of solar radiation. However, the main problem with CPV is the elevated PV surface temperature, which often requires active cooling. This issue can be solved by introducing a Concentrating Photovoltaic Thermal (CPVT) system. In this article, a new CPVT hybrid system based on Point Focus Fresnel Lens (PFFL) and embedded Multi Junction Photovoltaic (MJPV) (GaInP/InGaAs/Ge) cells has been experimentally investigated and numerically modelled under indoor conditions. Experiments and simulations were carried out at different heat transfer fluid (HTF) flow rates and under constant irradiation emitted from a sun simulator. The results indicate that the thermal and electrical performance of the CPVT system improves under the testing conditions, where the total efficiency was 68.7% and 73.5% for the experimental and CFD models, respectively. At the same time, the highest thermal efficiency of the experimental and CFD models was 49.5% and 55.4%, respectively. In contrast, the highest electrical efficiency was 36.5% and 37.1%. Therefore, the CPVT system has an excellent possibility of being competitive with conventional power generation systems.

A Production and Delivery Model of Hydrogen from Solar Thermal Energy in the United Arab Emirates

Hydrogen production from surplus solar electricity as energy storage for export purposes can push towards large-scale application of solar energy in the United Arab Emirates and the Middle East region; this region’s properties of high solar irradiance and vast empty lands provide a good fit for solar technologies such as concentrated solar power and photovoltaics. However, a thorough comparison between the two solar technologies, as well as investigating the infrastructure of the United Arab Emirates for a well-to-ship hydrogen pathway, is yet to be fully carried out. Therefore, in this study we aim to provide a full model for solar hydrogen production and delivery by evaluating the potential of concentrated solar power and photovoltaics in the UAE, then comparing two different pathways for hydrogen delivery based on the location of hydrogen production sites. A Solid Oxide Cell Electrolyzer (SOEC) is used for technical comparison, while the shortest routes for hydrogen transport were analyzed using Geographical Information System (GIS). The results show that CSP technology coupled with SOEC is the most favorable pathway for large-scale hydrogen from solar energy production in the UAE for export purposes. Although PV has a slightly higher electricity potential compared to CSP, around 42 GWh/km2 to 41.1 GWh/km2, respectively, CSP show the highest productions rates of over 6 megatons of hydrogen when the electrolyzer is placed at the same site as the CSP plant, while PV generates 5.15 megatons when hydrogen is produced at the same site with PV plants; meanwhile, hydrogen from PV and CSP shows similar levels of 4.8 and 4.6 megatons of hydrogen, respectively, when electrolyzers are placed at port sites. Even considering the constraints in the UAE’s infrastructure and suggesting new shorter electrical transmission lines that could save up to 0.1 megatons of hydrogen in the second pathway, production at the same site with CSP is still the most advantageous scenario.

Performance analysis of a novel building integrated low concentration photovoltaic skylight with seasonal solar control

This paper presents the development and performance demonstration of a novel low concentration PV skylight system that ensures seasonal solar control in buildings. It uses static Fresnel lenses that deviate solar radiation to the solar cells during the spring-summer period, increasing the electricity production while decreasing the heat into the building. During the autumn-winter period, the system allows the light to pass into the building, producing electricity as usual. Similar existing solutions normally only consider the PV performance but leave aside other energy parameters of the building. The development phase includes several mechanical, fire and PV tests. The new system is validated in two test benches: firstly, integrated as a skylight in the experimental FACT building at CEA INES in France; secondly, in a bigger system in Tecnalia facilities in Spain. In both cases, the system shows a significant increase of the PV production in the overall spring-summer period between 10 and 20% compared to an equivalent system without lenses. The measured cooling demand during spring-summer is reduced by 20% while daylighting in the building is not significantly affected. These advantages make this solution suitable to replace common non-photovoltaic glazing skylights and produce electricity while the solar gains are controlled in the building.

Numerical and experimental performance evaluation of a laser-concentrated photovoltaic-thermoelectric generator hybrid system.

Thermal management of concentrated photovoltaic (CPV) modules is essential to avoid the decrease in conversion efficiency caused by temperature rise during their operation. This is even more important for laser-concentrated CPV hybrid systems where out-of-control temperature rise is more likely to happen. In this research, a three-dimensional simulation model for a concentrated photovoltaic-thermoelectric (CPV-TE) hybrid system was studied to optimize its parameters and improve its conversion efficiency under laser radiation. Based on the simulation results, an integrated CPV-TE device was designed, fabricated, and tested under a high-power laser. The novel integrated CPV-TE system utilizes growing electrodes to encapsulate CPV directly on the TEG. Compared to conventional CPV-TE systems that utilize silicone-filled, the integrated CPV-TE system reduces contact thermal resistance and increases output power as well as conversion efficiency. To the best of our knowledge, this is the first study to discuss and optimize a CPV-TE hybrid system for laser radiation. In addition, this research improves the efficiency of laser energy conversion, increases the reliability and stability of the system, and may facilitate the promotion of optical wireless and fiber power transmission systems in future applications.

Characterization method and analysis of misalignments in micro-concentrator photovoltaic modules.

Micro-scale concentrator photovoltaics (micro-CPV) is an emerging trend for the development of high-efficiency, low-cost photovoltaic systems. The miniaturization of optics and cells offers advantages in terms of performance and enables differentiation in the PV market. However, the sub-millimeter size of the solar cells used, the intrinsic narrow angular tolerance of CPV optical systems (typically around 0.5° and 2°), and the massive number of cells per module lead to very tight mechanical tolerances. Therefore, determining the misalignments between cells and optics is important for quality control inspection of modules. In this paper, we describe a method for characterizing these misalignments based on image acquisition and its subsequent processing and apply it to a micro-CPV module composed of 572 lens-cell units. This method is validated, using a unique experimental technique that takes advantage of the tracking system embedded in the module. The statistical distributions of misalignments are compared for two tracking positions, residuals are determined and shows the consistency of the method. Finally, the impact of misalignment distributions on the IV curve of the module is discussed.

Numerical Study of Single-Layer and Stacked Minichannel-Based Heat Sinks Using Different Truncating Ratios for Cooling High Concentration Photovoltaic Systems

The present research aims to discuss and analyze the performance of truncated single-layer and stacked mini-channel-based heat sinks employed for the cooling of a single-cell high concentrating photovoltaic systems. The truncating technique of the fins at the entrance and exit regions from the internal fluid mini channels is opted to reduce the energy, raw material costs and time of the manufacturing process of the mini channels. This proposed solution is constrained by several metrics such as the thermal management and the overall performance of the high concentrating photovoltaic system. In the current research, the use of a truncating ratio of 31% has yielded minimum cell temperature and maximum electrical efficiencies for both single-layer and stacked mini-channel-based heat sinks, while a truncating ratio of 65% has enabled more uniform cell temperature distribution. Moreover, a truncating ratio of 65% has qualified the highest water outlet temperature and the lowest pressure drops relatively compared to the conventional mini-channel-based heat sink configurations. The highest water temperature has reached up to 52.7 ∘C by the stacked mini-channel-based heat sink with a truncating ratio of 65% under a geometrical concentration ratio of 2000× and a mass flow rate of 0.001kgs−1. For both the single-layer and stacked mini-channel-based heat sinks, the use of a truncating ratio of 65% has driven the upper hands to achieve higher ratio of the thermal power to the pumping power (RTP). The maximum RTP values have been recorded by the single-layer mini-channel-based heat sink with a truncating ratio of 65% equal to 23.61 ×106 and 233.06 ×103 at a mass flow rate of 0.008kgs−1 and 0.001kgs−1, respectively, under 2000×.