Performance Of Solar Concentrator Research Articles

Experimental and numerical analysis of multi-layer micro channel applied to parabolic solar concentrator

There are numerous applications for micro-channel technology, but it has just a few applications in solar collectors. Therefore this research makes a clear contribution in this field by using a new design absorber in the concentrator, and the reflector was designed to focus the solar radiation on two sides. The solar concentrator system was attached to the tracking system to maintain the parabolic collector's perpendicularity to sun rays. This study investigates the experimental and numerical effects of the micro-channel technique on solar concentrator performance for different velocity values to meet the need for temperature differences, which gives Reynolds numbers varying from 1011 to 3273. The absorber plate was made from aluminum metal with 44 rectangular microchannels (0.3 m in length, 0.02 m in width, and 0.0009 m in height). The result indicated that the two-axis tracking system would increase output temperature by roughly 18 %. Outlet air temperature decreased significantly by 13.9 °C with changing flow rate from 0.009339 to 0.030235 kg/s. The highest efficiency was 91 % in March, 89 % in November, 80 % in February, 69.8 % in December and 65.5 % in January. A good agreement was obtained between numerical and experimental with a maximum deviation of 1.4, 1.7, 9.4 and 8.88 % for the glass cover, absorber plate, upper channel and lower channel, respectively.

Ray tracing method applied in the annual evaluation of reflectors integrated to an evacuated tube solar collector

A method to evaluate the performance of annual solar concentrators is presented. The ray-tracing technique is regularly used to assess the solar concentrator's performance; however, most of the works in this area simplify the simulation process by considering representative scenarios throughout the year, such as solar tracking studies in summer and winter solstices or monthly averages to evaluate the annual system performance. The presented method develops annual simulations using dynamic data exchange protocol to allow communication between TracePro® and MATLAB with defined time intervals, applied to assess the integration of a reflector system to evacuated tube collectors under three configurations: rear reflector plate, compound parabolic concentrator, and parabolic concentrator; the finding that the latter presents the most favorable results, increasing the incident radiation on the outside of the tubes up to 36%.

Performance of Solar Concentrator with and without Mirror Coating Paper

The utilization of solar energy continues to be developed to get the best efficiency. This energy can be used for electricity generation, cooling, and/or drying. One technology that is still under development is the use of solar concentrators. Therefore, our paper aims to measure the performance of the development of a solar collection unit coated with mirror paper. Furthermore, the data is compared with the test data for solar concentrators without mirror paper that was carried out by previous researchers in 2019. The method used in this research is a field experiment. A simple statistical comparison method was carried out on the experimental data. Field testing was conducted after the solar concentrator was coated with mirror paper. The test was carried out for 5 days in full shining sun conditions in Sukabumi Regency, Indonesia. The surface coating of the solar concentrator with mirror paper has not been able to improve the performance of the solar concentrator satisfactorily. Solar concentrators can heat the fluid from its initial average temperature of 19.37 %.
 HIGHLIGHTS
 
 Several field tests were undertaken to determine the effectiveness of solar concentrators with and without mirror coated paper
 The fluid temperature heated with coated paper in a solar concentrator provides a higher temperature than without paper coating
 Solar concentrator with mirror coated paper has potential as an alternative for covering the surface of the solar concentrator
 
 GRAPHICAL ABSTRACT

Consensus statement: Standardized reporting of power-producing luminescent solar concentrator performance

<h2>Summary</h2> Fair and meaningful device performance comparison among luminescent solar concentrator-photovoltaic (LSC-PV) reports cannot be realized without a general consensus on reporting standards in LSC-PV research. Therefore, it is imperative to adopt standardized characterization protocols for these emerging types of PV devices that are consistent with other PV devices. This commentary highlights several common limitations in LSC literature and summarizes the best practices moving forward to harmonize with standard PV reporting, considering the greater nuances present with LSC-PV. Based on these practices, a checklist of actionable items is provided to help standardize the characterization/reporting protocols and offer a set of baseline expectations for authors, reviewers, and editors. The general consensus combined with the checklist will ultimately guide LSC-PV research towards reliable and meaningful advances.

Efficiency Evaluation of Solar Concentrator without Tracking System Type of Compound Parabolic Concentrator (CPC)

It is useful to analyze any optical system theoretically before proceeding with its design in order to ensure the effectiveness of the design through computer simulations that are important and useful in designs for the ability to predict the performance of solar concentrator under any conditions. For this design, non-sequential ray tracing mode wasused in the Zimax program with a light source that simulated solar radiation. The purpose of the design of a compound parabolic concentrator (CPC) is to take advantage of the solar radiation that falls on it without the need for an efficiently tracked system within certain limits of the angle of solar radiation fall known as the acceptance angle. That is, obtaining the largest possible number of rays received inside the CPC through reflections in the inner walls of it, which give a large amount of thermal energy to the surface of the recipient, which in turn gets this energy to be used to create electrical energy. The efficiency of receiving reflected solar radiation in this type of concentrator is great compared to other solar concentrators.&#x0D; Simulated design of solar reflector concentrator has been presented. The concentrator is a type of compound parabolic concentrator (CPC) involved of internal reflector surface (Hollow and within Poly methyl methacrylate (PMMA) polymer material) without tracking system. CPC has the property to overcome problems result from variation of incidence angle of the sun during daytime. Because the tracking system expensive and has technical problems. The efficiency of CPC has been obtained by using Zemax optical design program, for different designs has concentration ratio(c=1,2,3,4,5). That is, the ratio of the output aperture to the input aperture. Taking into account the angle of acceptance that plays a major role in the form of design and its efficiency the results are shown when designing the model with radial aperture of (50mm) and length of (500mm).The design of concentrations ratio is depends on the acceptance angle.&#x0D; c=5 at normal incident angle (ÆŸ=0). And it is almost similar if the material is used PMMA within CPC, and degradation of efficiency with increasing the incidence angle.

A review of Thermal Performance of Solar Concentrator – the future needs

Abundant solar energy is freely available almost round the year in India. As per the current scenario of global warming and climatic change, solar energy is the cleanest source in nature. Concentrated solar power (CSP)has hardly contributed to the overall installed solar power capacity in the country. CSP technologies are Parabolic Trough Collector (PTC), Linear Fresnel Reflector (LFR), Paraboloid Dish and Solar Power Tower. This paper presents a review of CSP in solar parabolic dish concentrator to understand thermal aspect like thermal efficiency, optical efficiency, useful heat gain, heat losses, solar irradiation, etc. for various applications and current development. The current scenario of global CSP is discussed to meet the future challenges and need of the society.

Evaluation of Optical performance of Solar Concentrator with Laminated Steel Reflectors

The International Scientific Research Organization for Science, Engineering and Technology (ISROSET) is a Non-Profit Organization; The ISROSET is dedicated to improvement in academic sectors of Science (Chemistry, Bio-chemistry, Zoology, Botany, Biotechnology, Pharmaceutical Science, Bioscience, Bioinformatics, Biometrics, Biostatistics, Microbiology, Environmental Management, Medical Science, Forensic Science, Home Science, Library Science, Material Science Military Science, Physical Science, Physical Education Science, Educational Science, Fisheries, seed technology, Agriculture, Forestry Science, Mathematics, Physics, Statistics and Geology/Earth Science), Computer Science, Engineering and Information Technology, Commerce, Management, Economics Sociology and Social Science.

Thermal and concentration performance for a wide range of available offset dish solar concentrators

This article incorporates an opto-geometric model to estimate the theoretical energy concentration performance of solar concentrators with Offset Parabolic Satellite Dishes (OPSDs). In addition, new methodologies and results are presented to characterize the solar energy capacities of offset reflectors of different sizes by means of computational simulations. The solar energy concentration capacity of these concentrators is evaluated for different aperture areas associated with commercially available OPSDs. The mathematical model is validated by comparing the results obtained by the simulator with the experimental results for an offset concentrator with a 0.7-m aperture diameter used to heat water in an open circuit with a serpentine receptor. Based on the numerical study, offset reflectors are available in a wide range of thermal energy concentration capacities ranging from 0.071 kWt to 5.08 kWt, with a receiver image width that varies from 0.006 m to 0.7 m. This range corresponds to collector aperture diameters of 0.45 m to 3.8 m. The offset concentrator is compared to other types of dish concentrators, and the results show that the cost of the OPSD concentrator is the lowest (0.47 €/Wt). Additionally, the geometric concentration value (958) is very similar to those of other offset concentrator geometries. Finally, due to the advantages of operation and maintenance and the high availability and low cost of offset reflectors, the potential for using these reflectors in solar energy applications should be evaluated based on the results and methodology outlined in this article.

Experimental investigation of the comparison of compound parabolic concentrator and ordinary heat pipe-type solar concentrator

In this research study, we have compared between the two different concentrators with the flat absorber plate receiver of the compound parabolic concentrator heat pipe solar concentrator and ordinary heat pipe flat plate solar concentrator. For the reproduction of solar radiation in the experiment, iodine tungsten lamp was used. Thermal performance comparison of the two types of solar concentrator under different simulating radiation intensity conditions was carried out with including the fluid temperature, instantaneous efficiency, average efficiency, and average heat loss coefficient. The results of the experiment indicate that the compound parabolic concentrator heat pipe-type solar concentrator not only increased the fluid temperature and instantaneous efficiency but also decreased the average heat loss coefficient as compared with the ordinary heat pipe flat plate solar concentrator. It was noticed from the experimental results that the efficiency of compound parabolic heat pipe solar concentrator was higher than ordinary heat pipe solar concentrator up to 6 and 10°C with the light intensity, that is I = 679 W/m2 and I = 892 W/m2, respectively. From the results, it was concluded that the using of compound parabolic heat pipe solar concentrator increased the thermal performance of solar concentrator.

Assessing the impact of optical errors in a novel 2-stage dish concentrator using Monte-Carlo ray-tracing simulation

Abstract Optical errors decrease the performance of solar concentrators. Here we assess the sensitivity of a novel 2-stage dish concentrator against optical errors. We use Monte Carlo ray-tracing, probability statistics, and optical geometrical principles in the analyses. The key finding is that the novel concentrator can reach a high radial distribution of flux concentration and high optical efficiency over a range of optical errors. Compared to a traditional 2-dish concentrator, the performance was clearly better. The results are in good agreement with results from the TracePro® tool. The results also imply improved tracking stability with the novel 2-stage dish concentrator.

Experimental Evaluation of the Solar Flux Distribution on the Flat Receiver of a Model Heliostat System

For the efficient utilization of solar energy, its concentration is required. Central Receiver systems have higher concentration ratio as compared to other concentrated solar power techniques. The solar flux density distribution and the temperature on the receiver plate are important parameters in assessing the net thermal energy, in predicting the performance of solar concentrator and in the design of solar receiver. Here the flux distribution on the flat receiver of the ganged type model heliostat system consisting of nine heliostats has been evaluated by using the thermocouple method which is the indirect method of flux measurement. The variation of the solar flux density distribution on the receiver plate have been estimated for the different numbers of heliostat by using the energy balance equation. For this model heliostat system the peak flux and average flux values are estimated to be 3950.57 (± 3%) W/m 2 and 1798.77 (± 3%) W/m 2 respectively. This analysis will be useful for sizing of the receiver. For the average flux value on the receiver plate the receiver size for the nine heliostats system will be 0.3m x 0.3m with the intercept factor of 64%.The average optical concentration ratio was 5.6 with the optical efficiency of the system 0.50 ± 3 % during the test period.

A vector based freeform approach for reflecting concentrator of solar energy

A vector based freeform approach is proposed for the geometrical reverse design of reflecting solar concentrators. The effect of solar cone angle of incident vectors is taken into consideration in the method based on three-dimensional freeform optics. The method developed is a closed-loop program and did not need any other commercial software. According to the transmission pattern of solar concentrators, the source-target mapping should be initially established prior to constructing an initial geometry formed by discrete points using the Geometric Construction Method. The freeform surface is generated by connecting several triangular flat elements defined by these points and then the Monte-Carlo ray tracing was conducted. The freeform surface can then be further optimized through feedback modifications. Finally, the optimal shape is obtained when the design examples are the off-axis freeform reflectors with target circular/rectangular receivers for the use of Concentrated Photovoltaic. This method provides a practical approach for improving the optical performance of solar concentrators.

Matlab PV solar concentrator performance prediction based on triple junction solar cell model

This paper deals with a generalized triple-junction solar cell model developed by using Matlab in order to predict the performances of a Photo Voltaic Thermal (PVT) solar concentrator. The triple-junction solar cell model represents each single junction included in the entire triple-junction solar cell. The model has been developed considering not only parameters related to the environmental conditions, but also considering the concentration factor. The proposed model allows all single junctions to be considered one by one, and therefore, it is suitable for modeling not only a specific triple junction solar cell, but also two junction solar cells and triple-junction solar cells made by different material. Moreover, the proposed model implementation allows for a thorough analysis under different environmental conditions. The proposed model is general and useful not only to estimate the system loss and solar cell degradation during operation, but also to evaluate the overall performance when solar cells are connected to MPPT (Maximum Power Point Tracking) electronic converters. The theoretical analysis is validated by experimental verification included in the paper.

Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators

The narrow-angle spectral specular reflectance and angular scattering of conventional and novel reflective materials for solar concentrators are measured over the wavelength range 300–2500nm at incidence angles ranging from 15° to 60° using a spectroscopic goniometry system. The solar-weighted specular reflectance at near normal incidence and an acceptance half-angle of 17.5mrad is 0.941 for back-silvered glass, 0.908–0.926 for silvered polymer films, 0.895 for aluminized polyester film, 0.939–0.954 for silvered aluminum sheets, and 0.860 for aluminized aluminum sheet. The angular scattering, quantified in terms of the standard deviation of a Gaussian distribution, is found to be negligible for aluminized polyester (<0.05mrad) and back-silvered glass (<0.07mrad), and noticeable for silvered polymer films (0.27–1.12mrad) and silvered aluminum sheets (0.12–1.66mrad). In addition, the spectral transmittance of semi-transparent materials suitable for protective covers is measured, yielding solar-weighted normal transmittance values of 0.913 and 0.946 for 100μm thin films of ETFE (ethylene-tetrafluoroethylene) and FEP (fluorinated ethylene propylene), respectively. The measured optical properties are incorporated in a Monte Carlo ray-tracing program and applied to analyze the optical performance of solar concentrators.

Test Standards for Direct Steam Generating Solar Concentrators

There are a few standards reported in the literature for testing and evaluation of thermal performance of solar concentrators based on sensible heating of working fluid. The preceding standard measures only the cooking efficiency and cooking capacity. Apart from thermal efficiency, there is an imperative need for other important parameters of the solar concentrators such as its stagnation temperature, cooking capacity, cost per watts delivered, weight of the cooker, ease of handling and aesthetics. The characterization of a concentrator at its operating temperature settles appropriate size and type of concentrator for any thermal application. The performance test is conducted at Chandwad (20.3292°N, 74.2444°E), Maharashtra and the proposed protocol aims for evaluation of thermal performance of solar cooking system and standardization of reporting the test results so that anyone can easily recognize and use it.

Experimental Verification and Analysis of Solar Parabolic Collector for Water Distillation

The paper is concerned with an experimental study of parabolic trough collector with its sun tracking system designed and manufactured to facilitate rapid diffusion and widespread use of solar energy. The paper focuses on use of alternative source of energy (through suns radiation) which is easy to install, operate and maintain. Also, to improve the performance of solar concentrator, different geometries were evaluated with respect to their optical and energy conversion efficiency. To assure good performance and long technical lifetime of a concentrating system, the solar reflectance of the reflectors must be high and long term stable. During the research carried out, focus had been shifted from evaluation of the performance of concentrating solar collector to analysis of the optical properties of reflector and absorbing materials. The shift of focus was motivated by the need to assess long term system performance and possibilities of optimizing the optical efficiency or reducing costs by using new types of reflector materials and absorbing materials. The Solar Parabolic Trough Collector (SPTC) was fabricated in local workshops and the sun tracking system was assembled using electric and electronic components in the market, while the mechanical components making up the driving system were procured from the local market. The objective of the research is to obtain distilled water by heating it to a higher temperature by solar parabolic trough collector. Solar distillation is used to produce potable water or to produce water for lead acid batteries or in chemical laboratories as in this case. The level of dissolved solids in solar distilled water is less than 3 ppm and bacteria free. The requirements for this specific design are a target for distilling water regularly with low maintenance.

The geometric-optics relation between surface slope error and reflected ray error in solar concentrators

In typical reflection-based solar concentrators, surface slope error mainly causes the reflected ray to deviate from the specular reflection direction and eventually from a target. Hence a fundamental understanding of the relation between surface slope error and reflected ray error is important for evaluating optical performance of solar concentrators. It has been widely accepted that when surface slope error follows the Rayleigh distribution, reflected ray error also follows. However, including this conventional relation, the relevant studies to date relied on purely geometric calculations and overlooked features of light scattering. In this study, the bidirectional reflectivity from geometric optics in light scattering theory is employed to derive a more rigorous distribution of reflected ray error. For the reflector surface without refraction, the geometric-optics relation demonstrates that the conventional relation holds only at normal incidence and becomes more and more incorrect as the incidence angle increases because of diminishing scattering effects. As a result, the conventional relation underestimates the peak flux produced by solar concentrators and their optical performance. The treatment that is able to account for scattering features and thereby overcome the limitations of the conventional relation is suggested in the use of the Monte Carlo ray-tracing method.

A simple method for studying the effect of scattering of the performance parameters of Parabolic Trough Collectors on the control of a solar field

This paper develops a novel and simple yet rigorous methodology that, by means of basic techniques and tools available to any engineer, enables the study of the effect of solar concentrator performance parameter scattering on the control of solar field outlet temperature. Several simulations are performed considering a realistic solar field comprised of a large set of solar collectors with slight differences in performance. Sets of scattered parameter distributions are randomly assigned to the collectors in the solar field. Sensitivity analysis of solar field behavior is then performed in terms of the distribution of the performance parameters of the solar collectors, followed by a comparison between different configurations of the solar field according to the number of subfields. The latter is of a great interest in order to evaluate the effect of subfield number on the ability of the solar field’s operator to control the temperature of the solar field when a flow control valve is not available in each loop.

집광 열유속 측정과 모델링의 비교를 통한 집광 오차 평가

Concentration errors critically affect the performance of solar concentrator, so their evaluation is important to the concentrated solar power technology. However, the evaluation is very challenging because error sources are various and not easy to measure individually. Therefore, the integrated effect of concentration errors is often more interesting and useful for large-scale applications. In the present work, we analytically investigate and classify various concentration error sources and then explain that the effect of various concentration errors can be represented in terms of a root mean square value of reflector surface slope error. We present an indirect approach to assessing the reflector surface slope error by comparing solar flux measurement data with modeling calculations. We apply the approach for solar furnaces with different thermal capacity and investigate its advantages and disadvantages.

Performance of solar concentrator made of an achromatic Fresnel doublet measured with a continuous solar simulator and comparison with a singlet

A primary optics for solar concentrator made of an achromatic Fresnel doublet has been designed and manufactured. The achromatic Fresnel doublet combines the advantages of plastic lenses without being affected by chromatic aberrations. The performance has been determined experimentally using a homemade continuous solar simulator and compared to paraxial theory and ray-tracing simulations. Experimental results are in good agreement with theory and show that the achromatic Fresnel doublet is tolerant to manufacturing errors and uncertainty on the dispersion of the refractive index: the concentration factor remains above 1600× with an f-number of 2.