Asymmetric Compound Parabolic Concentrator Research Articles

Asymmetrical compound parabolic concentrator with single flow system: field-test scale, thermal performance parameters, and E. coli inactivation

This work presents a developed field-test scaled asymmetrical compound parabolic concentrator (ACPC) and an investigation of its performance with a single flow system of water on Escherichia coli inactivation. As a function of water flow rate, ability to produce hot water of the ACPC and hence inhibit the growth of bacterial in water is focused to study; the flow rates varied are 0.2, 0.4, and 0.6 l min−1. With a design and choice of material, the constructed ACPC unit with 0.2 l min−1 could produce hot water with maximum temperature of 76.4 °C, with lower flow rates resulting in the lower outlet water temperature and consequently the reduced kinetics of bacteria inactivation. Thermal performance parameters have been described in a correlative view with the particular operation condition and flow rate variables through mathematic calculation. The effect of inlet driving temperature, believed to play a significant role controlling the outlet temperature, on E. coli inactivation has been investigated.

Optical design and experiment evaluation of a novel asymmetric compound parabolic concentrator (ACPC) integration with PV for building south wall application

Compound parabolic concentrator (CPC) as a typical low-concentration-ratio concentrator is an interesting topic for it can work as the static concentrator without any additional tracking systems or seasonal adjustments, which shows a promising concept of introducing the concentrating PV technology for building application. Therefore, based on the compound parabolic curves, a novel asymmetric compound parabolic concentrator (ACPC) is proposed in this paper for building south wall integration. The optical model of the ACPC is built by the software Lighttools to study its optical performance, and the structure parameters of it are optimized through the optical simulation. Then the prototype of the ACPC integrated with the PV cell as the ACpC-PV module is manufactured and assembled. The indoor experiments by the solar simulator (Oriel Sol3A Model 90943A) from the Newport Corporation at the dark environment with the temperature of 25 °C are conducted to study the electrical performance of the ACPC-PV module. The simulation and experiment results show that the acceptance range of the ACPC with the geometric concentration ratio of 2.4X can be 65° with high optical efficiency. A good agreement is observed between the simulation and experiment results despite the deviation of around 13% which is inevitable due to all kinds of errors, such as manufacturing errors, mismatch losses, series resistance losses, etc.

Review of Mathematical Equations for the Design of Compound Parabolic Concentrating Solar Energy Collectors

Compound Parabolic Concentrator (CPC) is the most popular static low-concentrating system for solar energy collection. The main advantages of CPCs over other solar collectors include high optical efficiency, elimination of the diurnal tracking requirement at intermediate concentrations and being able to collect both diffuse and direct radiation. The overall performance of CPCs depends on the accurate design of solar radiation reflecting surfaces, which is based on the edge-ray principle and identical optical length principle. However, most students and junior researchers in the field of solar energy find it difficult to design CPCs. The reason is that they cannot fully understand the design principles of CPCs and derive mathematical equations of the reflectors, thus they are only interested in the design equations. In this study, an attempt has been made to review all mathematical equations that have been used to design symmetric and asymmetric CPCs with different receiver configurations. This article offers an opportunity for researchers to obtain accurate information more quickly than going through past publications in the hope of finding something relevant. It is anticipated that the results from this study will increase the application of CPCs to photovoltaics and/or thermal conversions.

Design and Development of a Lens-walled Compound Parabolic Concentrator-A Review

Compound parabolic concentrator (CPC) is a representative among solar concentrators, one of whose disadvantage is that the concentration ratio limits the half acceptance angle. Based on this, researchers put forward a novel structure, named the lens-walled CPC. This paper reviews the design and development of lens-walled CPC. The structure of the symmetric and asymmetric lens-walled CPC and the improved ones are presented, and their indoor and outdoor performances are also illustrated. The lens-walled CPC has a larger half acceptance angle and a more uniform flux distribution that is suitable for PV application. Furthermore, the life-cycle assessment for building integrated with PV is performed and it shows that the energy payback time of such integrated system has a significant advantage. In addition, future research areas are also indicated that may provide more functions and more stable performance. The design methods and developmental directions given in this study would provide many references in solar optical research and solar concentrator optimization.

Design and development of a Building Façade Integrated Asymmetric Compound Parabolic Photovoltaic concentrator (BFI-ACP-PV)

Building Integrated PV and Concentrating PV can generate electricity onsite and provide savings in materials and electricity costs, as well as protecting buildings from weather. In this paper, a novel truncated stationary asymmetric compound parabolic photovoltaic concentrator with a geometric concentration ratio of 2.0 has been designed and experimental characterised. The designed system is suitable for building façade application, especially for vertical façade. It has wide acceptance half angles of 0° and 55°, this acceptance angle range enables the concentrator to operate year-round at its geometric gain in most of the UK and EU climatic condition. A comprehensive indoor test was carried out to evaluate the electrical and thermal characterisation of the developed Building Façade Integrated Asymmetric Compound Parabolic Photovoltaic concentrator (BFI-ACP-PV) system, and also the factors that affect the power output of the developed system. The experimental results showed that the developed BFI-ACP-PV system has the potential to increase the power output per unit solar cell area by a factor of 2, when compared with a non-concentrating PV system. Subsequently, a Phase Change Material (PCM) system was integrated to the rear of the BFI-ACP-PV system to moderate the PV temperature rise and maintain good solar to electrical conversion efficiency. It was found out that the electrical conversion efficiency for the BFI-ACP-PV coupled PCM system was increased by over 5% compared with a similar system with no PCM integrated at the rear, when the incident solar radiation intensity was 280 W/m2, this value increased by over 10% for an incident solar radiation intensity of 670 W/m2.

Numerical and lab experiment study of a novel concentrating PV with uniform flux distribution

The uniform illumination profile that falls on the PV cell is good for PV output and lifespan, however the flux distribution of the concentrating PV appears to be non-uniform in most cases which is harmful for the overall performance of the concentrating photovoltaic. In order to overcome this disadvantage, a novel asymmetric compound parabolic concentrator concentrating PV with uniform flux distribution is proposed in this paper. A two-dimensional finite element model is built for electrical performance simulation of the concentrating photovoltaic module. The prototype of the concentrating photovoltaic module is manufactured and assembled to conduct the indoor lab experiment under Standard Test Condition to verify the feasibility and reliability of the model. The outdoor experiments are conducted to show the electrical performance of the concentrating photovoltaic module under the real weather condition. Then the model is used to analyze the electrical performance of the PV cell under the flux distribution created by the proposed concentrator. The results show that the electrical performance of the proposed concentrating photovoltaic module is close to that under the uniform flux distribution with the same total radiation level, which confirms that the proposed concentrator is beneficial for the PV output under concentrating illumination due to uniform flux distribution.

Life-cycle assessment of a low-concentration PV module for building south wall integration in China

Low-concentration PV (CPV, concentrating photovoltaic) technology is a promising concept because it can work with the fixed installation. However, besides the economic consideration, the environmental impacts of the CPV module throughout its life cycle should be addressed as compared with the flat PV technology. Thus, in this paper, a novel high optical performance low-concentration concentrator namely asymmetric compound parabolic concentrator (aCPC) for building south wall integration is proposed. And based on the proposed aCPC-PV module, a life cycle assessment (LCA) has been performed for the low-concentration PV in China to make a scientific comparison with the PV module with the same output level environmentally. Several environmental indicators are calculated for Beijing, Hefei, Lhasa, Lanzhou, Harbin. The primary energy demand, energy payback time and environmental impacts are considered over the entire life cycle of the aCPC-PV module. The results show that the primary energy demand, energy payback time and environmental impacts of the aCPC-PV module are all relatively lower than that of the PV module with the same output. It is confirmed by the LCA study that the aCPC-PV module on behalf of the low-concentration PV technology is still a feasible and effective way for actual engineering because it’s more economic and more environmental friendly than the PV technology although the PV is experiencing continuous decrease in price and increase in efficiency.

Design and Optical Evaluation of a Novel Asymmetric Lens-Walled Compound Parabolic Concentrator (ALCPC) Integration with Building South Wall

Design and Optical Evaluation of a Novel Asymmetric Lens-Walled Compound Parabolic Concentrator (ALCPC) Integration with Building South Wall

Optimization design and performance analysis of a novel asymmetric compound parabolic concentrator with rotation angle for building application

A novel asymmetric lens-walled compound parabolic concentrator (ALCPC) for integration with the building south wall was proposed and manufactured. Besides of the asymmetric lens-walled structure, the special rotation angle at the bottom is also introduced to optimize the performance. The electrical and optical performance of the ALCPC-PV was detailed analyzed through the experiment and ray tracing simulation. The indoor experiment was conducted by a solar simulator (Oriel Sol3A Model 90943A) from Newport Corporation at the dark environment with the temperature of 25 °C. Form the experiment results, the ALCPC increases the maximum power by a ratio of 1.74x compared to the bare cell. The decrease of the geometric concentration ratio is mainly due to manufacturing errors, mismatch losses, series resistance losses, etc. The optical performance of the ALCPC was also investigated by the software Lighttools, and the optical efficiency and the distribution percentage of the energy collected through the total internal reflection and the specular reflection at different incidence angles are identified at various incidence angles. A good agreement is observed between the experiment results and the ray tracing results. The optical efficiency at the incidence angles of 0–60° is all within 90% of its peak value which means that the proposed ALCPC can achieve 60° acceptance angle with high optical efficiency that it shows a good potential as a static concentrator for the building south wall integration.

Experimental evaluation of a solar window incorporating rotationally asymmetrical compound parabolic concentrators (RACPC)

Building integrated photovoltaic (BIPV) systems have been proposed to make solar photovoltaic systems more attractive. These systems are not only capable of generating electricity, but can also contribute to minimise energy consumption in buildings by providing natural illumination, space and water heating, ventilation and shading. Despite these advantages, one of the issues that still prevents the widespread adoption of BIPV systems is their high capital cost. This paper discusses a novel type of non-imaging optical concentrator that can be used to reduce the capital cost of a BIPV system. This new concentrator, known as rotationally asymmetrical compound parabolic concentrator (RACPC), has a flat entrance aperture that facilitates integration within a double-glazing window and reduces fabrication costs. The RACPC, which has a geometrical concentration of 3.66x, also offers other advantages over conventional solar concentrators: suitability for fenestration, ease of integration with square PV cells, and passive tracking. Several experiments were carried out on a double-glazing solar window incorporating an array of 4x3 concentrator-PV cells. The experiments were carried out indoors under standard test conditions. The results show that the RACPC-PV window effectively increases the short-circuit current by a factor of over 3 at normal incidence when compared with a non-concentrated solar window. The solar window also shows an increase in maximum power generation by a factor of nearly 3.

Étendue and angular acceptance of the asymmetric compound parabolic concentrator

Although the use of the asymmetric compound parabolic concentrator (ACPC) for solar concentration has been addressed, documentation regarding etendue and angular acceptance of the ACPC is absent from the literature. This paper delves into the two-dimensional design of the ACPC and discusses its etendue and angular acceptance, offering a design tool regarding such instances when symmetry is broken. It is found that unlike the compound parabolic concentrator whose angular acceptance fills a symmetric ellipse, the ACPC’s angular acceptance fills an asymmetric ellipse in some cases and a folded ellipse in others. Both cases are dependent on the maximum acceptance angles of the design. Ray tracing is utilized to confirm the angular acceptance ellipses and etendue, as well as to offer a visual representation of the intensity distribution for asymmetric designs in both angular and phase spaces.

Potential of Implementing the Low Concentration Photovoltaic Systems in the United Kingdom

This paper discusses the prospect of integrating a novel type of low concentration photovoltaic (LCPV) design known as the rotationally asymmetrical compound parabolic concentrator (RACPC) in a building in the United Kingdom. This is done by proposing a number of building integration designs to create a zero carbon building. A cost reduction analysis of installing the LCPV systems in the country is also presented. It was found that an RACPC design could reduce the LCPV module’s manufacturing cost by 31.75% and the LCPV module’s cost per unit power output by 33.87% when compared with the conventional PV module.

Six-parameter electrical model for photovoltaic cell/module with compound parabolic concentrator

It is known that compound parabolic concentrators (CPCs) can improve electrical performance of a photovoltaic (PV) flat-plate system. However, a lumped electrical model of a PV cell/module with CPC for assessing performance under different operating conditions is unavailable. In this paper, a six-parameter based model is developed and applied to a PV cell, two PV models with CPC, and a PV module with 2D asymmetric CPC (trough). For validation, CPC with a single PV cell and two CPC modules with 2×2 and 9×9 PV cells are fabricated and measured in an indoor laboratory under standard test conditions. Results show that the optimised algorithm precisely predicts the six model parameters. A sensitivity analysis is performed to identify the importance of each parameter in the model. Ideality factor, circuit current and reverse saturation current are found to be the most dominant factor, while shunt resistance is the least important with CPC gain coefficient and series resistance are in between. Transient performance of a PV cell with CPC under variable outdoor climate conditions is also examined by coupling optical, thermal and electrical effects.

Design and experiment of a new solar air heating collector

This paper presents the design and experiment of a CTAH (Concentrating Transpired Air Heating) system. A newly designed solar air heating collector comprised of an inverted perforated absorber and an asymmetric compound parabolic concentrator was applied to increase the intensity of solar radiation incident on the perforated absorber. An extensive literature review was carried out to find the vital factors to improve optical and thermal efficiency of solar air heating systems. A stationary optical concentrator has been designed and experimented. Experimental thermal efficiency remained high at higher air flow rates. The average thermal efficiency was found to be approximately 55%–65% with average radiation above 400 W/m2 for flow rates in the range of 0.03 kg/s/m2 to 0.09 kg/s/m2. Experimental results at air flow rates of 0.03 kg/s/m2 and 0.09 kg/s/m2 showed temperature rise of 38 °C and 19.6 °C respectively at a solar radiation intensity of 1000 W/m2. A comparative performance study shows the thermal performance of CTAH. As the absorber of the CTAH facing downward, it avoids radiation loss and the perforated absorber with tertiary concentrator reduces thermal losses from the system.

Performance analysis of a novel rotationally asymmetrical compound parabolic concentrator

Abstract The low-concentration photovoltaic (LCPV) system has been identified as one of the potential solutions in lowering the overall installation cost of a building integrated photovoltaic (BIPV) system. This paper evaluates the performance of a novel type of LCPV concentrator known as the rotationally asymmetrical compound parabolic concentrator (RACPC). A specific RACPC design with a geometrical concentration ratio of 3.6675× was fabricated and integrated with a 1 cm by 1 cm monocrystalline laser grooved buried contact silicon solar cell. This design was tested indoors to evaluate its current–voltage ( I – V ), angular response and thermal characteristics. Under standard test conditions, it was found that the RACPC increases the short circuit current by 3.01× and the maximum power by 3.33× when compared with a bare solar cell. The opto-electronic gain from the experiment showed good agreement when compared with the simulation results, with a deviation of 11%.

Optical Performance Comparison of Six ACPCs for Concentrating Radiation on All-Glass Evacuated Solar Tubes

In this work, six asymmetric compound parabolic concentrators (ACPC) were designed for concentrating radiation on all-glass evacuated solar tubes (EST). The ACPCs are required to be horizontally oriented in the east-west direction and to collect direct sunlight for at least 6 hrs in any day of a year. The angular dependence of optical efficiency of six ACPCs, identical in the height of both reflectors after the higher reflector being truncated, was investigated by ray-tracing method, and the annual radiation on EST concentrated by ACPCs was estimated based on solar geometry and monthly horizontally radiation. Results shows that the ACPC designed based on “hat shaped” virtual absorber with a V-groove at the bottom of reflectors is the best in terms of the optical efficiency averaged over the acceptance angle, followed by the one designed based on “hat-shaped” absorber without a V-groove at the bottom, and the one designed based on the cover tube of EST is the worst. However, from the point of annual radiation on EST, the ACPC designed based on the cover tube is the best solution, followed by the one designed based on “ice-cream shaped” absorber and the one designed based on “hat shaped” absorber is the worst due to the smallest geometric concentration factor.

Rotationally asymmetrical compound parabolic concentrator for concentrating photovoltaic applications

This paper describes a novel type of solar concentrator – a rotationally asymmetrical compound parabolic concentrator (RACPC). The RACPC aims at addressing the following objectives: (i) to increase the electrical output of a concentrating photovoltaic (CPV) system by providing sufficient concentration gain; (ii) to minimise the usage of the PV material with the corresponding reduction of CPV system cost, and (iii) to eliminate the requirement of mechanical tracking by providing a wide field-of-view. This paper first provides a short review on variations of compound parabolic concentrator designs available to date. Next, the process of designing the RACPC is presented and the geometrical concentration gain of the concentrator is discussed. In addition, the optical concentration gain is also presented for various angles of incidence. Through simulations, it is demonstrated that the RACPC can provide significant optical concentration gains within its designed acceptance angle. An RACPC based system is an attractive alternative to conventional solar photovoltaic systems.

Enhancing performance of a linear dielectric based concentrating photovoltaic system using a reflective film along the edge

In the present study, we model and analyse the performance of a dielectric based linear concentrating photovoltaic system using ray tracing and finite element methods. The results obtained are compared with the experiments. The system under study is a linear asymmetric CPC (Compound Parabolic Concentrator) designed to operate under extreme incident angles of 0° and 55° and have a geometrical concentration ratio of 2.8×. Initial experiments showed a maximum PR (power ratio) of 2.2 compared to a non concentrating counterpart. An improvement to this has been proposed and verified by adding a reflective film along the edges of the concentrator to capture the escaping rays and minimise optical losses. The addition of the reflective film changes the incoming distribution on the solar cell. Results show an increase of 16% in the average power output while using this reflective film. On including the thermal effects it was found that the overall benefit changes to about 6% while using a reflective film. Additionally, the effects of the non-uniformity of the incoming radiation are also analysed and reported for both the cases. It is found that adding the reflective film drops the maximum power at the output by only 0.5% due to the effect of non-uniformity.

Solar cooking development in Algerian Sahara: Towards a socially suitable solar cooker

Abstract This paper presents a review of research works and studies carried out in the development of solar cooking in Algerian Sahara. The review is performed in such way to focus on diverse box type solar cookers that have been realized by the solar heating research team at the Research Unit in Renewable Energies in Sahara Medium (URER/MS-Adrar, Algerian Sahara). Research started with the realization of a simple solar box cooker with a tilted absorber-plate, then the construction of a double exposure solar cooker and then the development of a novel non-tracking solar box cooker, which is equipped with a fixed asymmetric compound parabolic concentrator (CPC) as booster-reflector and its absorber-plate, is in a form of a step. The last cooker can be fixed at a south building wall with its rear opening in kitchen; it can be more user friendly. This will allow a freedom of interactive cooking and it does not require the user to go out in the sun during its use. These qualities promote its uptake and made it a socially acceptable device.

Performance evaluation of concentrating solar photovoltaic and photovoltaic/thermal systems

Hybrid conversion of solar radiation, which allows simultaneous conversion of sunlight into thermal and electrical energy in the photovoltaic/thermal collector, is one of the most promising techniques of solar energy exploitation. In this study, low concentrating photovoltaic (PV) and photovoltaic/thermal (PVT) systems were designed and tested for a given spring climatic condition of the Tunisian Saharan city Tozeur. The system is basically an asymmetric compound parabolic photovoltaic concentrator. As this system’s performance deteriorates with rising the solar cells temperature, we proposed to convert it on a hybrid one in order to improve its electrical efficiency and to recuperate simultaneously thermal energy. The comparison of these systems operating confirmed the improvement of the electrical performance of the combined PVT system and its acceptable thermal energy production. A computational fluid dynamics “CFD” model which interprets the PVT system was then developed and validated against the experimental results, proving the validity of the developed model use to identify numerically this system limitations and predict the possible improvements.