Search results for: Large Scale Floating Solar
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 13007

Search results for: Large Scale Floating Solar

12317 Experimental Study and Analysis of Parabolic Trough Collector with Various Reflectors

Authors: Avadhesh Yadav, Balram Manoj Kumar

Abstract:

A solar powered air heating system using parabolic trough collector was experimentally investigated. In this experimental setup, the reflected solar radiations were focused on absorber tube which was placed at focal length of the parabolic trough. In this setup, air was used as working fluid which collects the heat from absorber tube. To enhance the performance of parabolic trough, collector with different type of reflectors were used. It was observed for aluminum sheet maximum temperature is 52.3ºC, which 24.22% more than steel sheet as reflector and 8.5% more than aluminum foil as reflector, also efficiency by using Aluminum sheet as reflector compared to steel sheet as reflector is 61.18% more. Efficiency by using aluminum sheet as reflector compared to aluminum foil as reflector is 18.98% more.

Keywords: parabolic trough collector, reflectors, air flow rates, solar power, aluminum sheet

Procedia PDF Downloads 360
12316 Assessing Female Students' Understanding of the Solar System Concepts by Implementing I-Cube Technology

Authors: Elham Ghazi Mohammad

Abstract:

This study examined the female students’ understanding for the solar system concepts through the utilization of the I-Cube technology as a virtual reality technology. The study conducted in Qatar University for samples of students of eighth and ninth preparatory grade students in the State of Qatar. The research framework comprises designated quantitative research designs and methods of data collection and analysis including pre- and post-conceptual exams. This research based on experimental method design that focuses on students’ performance and conceptual questions. A group of 120 students from the eighth and ninth groups were divided into two pools of 60 students each, where the two 60-student groups represent the designated control and treatment groups. It must be mentioned that the students were selected randomly from the eighth and ninth grades. The solar system lesson of interest was taught by teacher candidates (senior students at the college of Education at QU), who taught both the experimental group (integrating I-cube) in virtual lab in Qatar University and control group (without integrating this technology) in one of independent school in the State of Qatar. It is noteworthy to mention that the students usually face some difficulties to learn by imagining real situation such as solar system and inner planet lesson. Collected data was statistically analyzed using one-way ANOVA and one-way ANCOVA using SPSS Statistics. The obtained results revealed that integrating I-Cube technology has significantly enhanced female students’ conceptual understanding of the solar system. Interestingly, our findings demonstrated the applicability of utilizing integrating I-Cube technology toward enhancing the students’ understanding regarding subjects of interests within the landscapes of basic sciences.

Keywords: virtual lab, integrating technology, I-Cube, solar system

Procedia PDF Downloads 239
12315 Optimum Dispatching Rule in Solar Ingot-Wafer Manufacturing System

Authors: Wheyming Song, Hung-Hsiang Lin, Scott Lian

Abstract:

In this research, we investigate the optimal dispatching rule for machines and manpower allocation in the solar ingot-wafer systems. The performance of the method is measured by the sales profit for each dollar paid to the operators in a one week at steady-state. The decision variables are identification-number of machines and operators when each job is required to be served in each process. We propose a rule which is a function of operator’s ability, corresponding salary, and standing location while in the factory. The rule is named ‘Multi-nominal distribution dispatch rule’. The proposed rule performs better than many traditional rules including generic algorithm and particle swarm optimization. Simulation results show that the proposed Multi-nominal distribution dispatch rule improvement on the sales profit dramatically.

Keywords: dispatching, solar ingot, simulation, flexsim

Procedia PDF Downloads 300
12314 Thiazolo[5,4-D]Thiazole-Core Organic Chromophore with Furan Spacer for Organic Solar Cells

Authors: M. Nazim, S. Ameen, H. K. Seo, H. S. Shin

Abstract:

Energy is the basis of life and strong attention has been growing for the cost-effective energy production. Recently, solution-processed small molecule organic solar cells (SMOSCs) have grown much attention due to the wages such as well-defined molecular structures, definite molecular weight, easy synthesis and easy purification techniques. In particular, the size of donor (D) and acceptor (A) unit is a crucial factor for the exciton-diffusion towards D-A interface and then charge-separation for the effective charge-transport to the electrodes. Furan-bridged materials are more electron-rich, high fluorescence, with better molecular-packing, and greater rigidity and greater solubility than their thiophene-counterparts In this work, a furan-bridged thiazolo[5,4-d]thiazole based organic small molecule (RFTzR) was formulated and applied for BHJ organic solar cells (OSCs). The introduction of furan spacer with two terminal alkyl units improved its absorption and solubility in the common organic solvents, significantly. RFTzR exhibited a HOMO and LUMO energy levels of -5.36 eV and -3.14 eV, respectively. The fabricated solar cell devices of RFTzR (donor) with PC60BM (acceptor) as photoactive materials showed high performance of 2.72% (RFTzR:PC60BM, 2:1, w/w) ratio with open-circuit voltage of 0.756 V and high photocurrent density of 10.13 mA/cm².

Keywords: chromophore, organic solar cells, photoactive materials, small molecule

Procedia PDF Downloads 163
12313 Designing Sustainable and Energy-Efficient Urban Network: A Passive Architectural Approach with Solar Integration and Urban Building Energy Modeling (UBEM) Tools

Authors: A. Maghoul, A. Rostampouryasouri, MR. Maghami

Abstract:

The development of an urban design and power network planning has been gaining momentum in recent years. The integration of renewable energy with urban design has been widely regarded as an increasingly important solution leading to climate change and energy security. Through the use of passive strategies and solar integration with Urban Building Energy Modeling (UBEM) tools, architects and designers can create high-quality designs that meet the needs of clients and stakeholders. To determine the most effective ways of combining renewable energy with urban development, we analyze the relationship between urban form and renewable energy production. The procedure involved in this practice include passive solar gain (in building design and urban design), solar integration, location strategy, and 3D models with a case study conducted in Tehran, Iran. The study emphasizes the importance of spatial and temporal considerations in the development of sector coupling strategies for solar power establishment in arid and semi-arid regions. The substation considered in the research consists of two parallel transformers, 13 lines, and 38 connection points. Each urban load connection point is equipped with 500 kW of solar PV capacity and 1 kWh of battery Energy Storage (BES) to store excess power generated from solar, injecting it into the urban network during peak periods. The simulations and analyses have occurred in EnergyPlus software. Passive solar gain involves maximizing the amount of sunlight that enters a building to reduce the need for artificial lighting and heating. Solar integration involves integrating solar photovoltaic (PV) power into smart grids to reduce emissions and increase energy efficiency. Location strategy is crucial to maximize the utilization of solar PV in an urban distribution feeder. Additionally, 3D models are made in Revit, and they are keys component of decision-making in areas including climate change mitigation, urban planning, and infrastructure. we applied these strategies in this research, and the results show that it is possible to create sustainable and energy-efficient urban environments. Furthermore, demand response programs can be used in conjunction with solar integration to optimize energy usage and reduce the strain on the power grid. This study highlights the influence of ancient Persian architecture on Iran's urban planning system, as well as the potential for reducing pollutants in building construction. Additionally, the paper explores the advances in eco-city planning and development and the emerging practices and strategies for integrating sustainability goals.

Keywords: energy-efficient urban planning, sustainable architecture, solar energy, sustainable urban design

Procedia PDF Downloads 76
12312 Mathematical Modelling of Drying Kinetics of Cantaloupe in a Solar Assisted Dryer

Authors: Melike Sultan Karasu Asnaz, Ayse Ozdogan Dolcek

Abstract:

Crop drying, which aims to reduce the moisture content to a certain level, is a method used to extend the shelf life and prevent it from spoiling. One of the oldest food preservation techniques is open sunor shade drying. Even though this technique is the most affordable of all drying methods, there are some drawbacks such as contamination by insects, environmental pollution, windborne dust, and direct expose to weather conditions such as wind, rain, hail. However, solar dryers that provide a hygienic and controllable environment to preserve food and extend its shelf life have been developed and used to dry agricultural products. Thus, foods can be dried quickly without being affected by weather variables, and quality products can be obtained. This research is mainly devoted to investigating the modelling of drying kinetics of cantaloupe in a forced convection solar dryer. Mathematical models for the drying process should be defined to simulate the drying behavior of the foodstuff, which will greatly contribute to the development of solar dryer designs. Thus, drying experiments were conducted and replicated five times, and various data such as temperature, relative humidity, solar irradiation, drying air speed, and weight were instantly monitored and recorded. Moisture content of sliced and pretreated cantaloupe were converted into moisture ratio and then fitted against drying time for constructing drying curves. Then, 10 quasi-theoretical and empirical drying models were applied to find the best drying curve equation according to the Levenberg-Marquardt nonlinear optimization method. The best fitted mathematical drying model was selected according to the highest coefficient of determination (R²), and the mean square of the deviations (χ^²) and root mean square error (RMSE) criterial. The best fitted model was utilized to simulate a thin layer solar drying of cantaloupe, and the simulation results were compared with the experimental data for validation purposes.

Keywords: solar dryer, mathematical modelling, drying kinetics, cantaloupe drying

Procedia PDF Downloads 126
12311 Influence of Channel Depth on the Performance of Wavy Fin Absorber Solar Air Heater

Authors: Abhishek Priyam, Prabha Chand

Abstract:

Channel depth is an important design parameter to be fixed in designing a solar air heater. In this paper, a mathematical model has been developed to study the influence of channel duct on the thermal performance of solar air heaters. The channel depth has been varied from 1.5 cm to 3.5 cm for the mass flow range 0.01 to 0.11 kg/s. Based on first law of thermodynamics, the channel depth of 1.5 cm shows better thermal performance for all the mass flow range. Also, better thermohydraulic performance has been found up to 0.05 kg/s, and beyond this, thermohydraulic efficiency starts decreasing. It has been seen that, with the increase in the mass flow rate, the difference between thermal and thermohydraulic efficiency increases because of the increase in pressure drop. At lower mass flow rate, 0.01 kg/s, the thermal and thermohydraulic efficiencies for respective channel depth remain the same.

Keywords: channel depth, thermal efficiency, wavy fin, thermohydraulic efficiency

Procedia PDF Downloads 372
12310 Performances Analysis and Optimization of an Adsorption Solar Cooling System

Authors: Nadia Allouache

Abstract:

The use of solar energy in cooling systems is an interesting alternative to the increasing demand of energy in the world and more specifically in southern countries where the needs of refrigeration and air conditioning are tremendous. This technique is even more attractive with regards to environmental issues. This study focuses on performances analysis and optimization of solar reactor of an adsorption cooling machine working with activated carbon-methanol pair. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber that is the most important component of the machine. The results show the poor heat conduction inside the porous medium and the resistance between the metallic wall and the bed engender the important temperature gradient and a great difference between the metallic wall and the bed temperature; this is considered as the essential causes decreasing the performances of the machine. For fixed conditions of functioning, the total desorbed mass presents a maximum for an optimal value of the height of the adsorber; this implies the existence of an optimal dimensioning of the adsorber.

Keywords: solar cooling system, performances Analysis, optimization, heat and mass transfer, activated carbon-methanol pair, numerical modeling

Procedia PDF Downloads 439
12309 Comparison between the Efficiency of Heterojunction Thin Film InGaP\GaAs\Ge and InGaP\GaAs Solar Cell

Authors: F. Djaafar, B. Hadri, G. Bachir

Abstract:

This paper presents the design parameters for a thin film 3J InGaP/GaAs/Ge solar cell with a simulated maximum efficiency of 32.11% using Tcad Silvaco. Design parameters include the doping concentration, molar fraction, layers’ thickness and tunnel junction characteristics. An initial dual junction InGaP/GaAs model of a previous published heterojunction cell was simulated in Tcad Silvaco to accurately predict solar cell performance. To improve the solar cell’s performance, we have fixed meshing, material properties, models and numerical methods. However, thickness and layer doping concentration were taken as variables. We, first simulate the InGaP\GaAs dual junction cell by changing the doping concentrations and thicknesses which showed an increase in efficiency. Next, a triple junction InGaP/GaAs/Ge cell was modeled by adding a Ge layer to the previous dual junction InGaP/GaAs model with an InGaP /GaAs tunnel junction.

Keywords: heterojunction, modeling, simulation, thin film, Tcad Silvaco

Procedia PDF Downloads 369
12308 A New Method to Winner Determination for Economic Resource Allocation in Cloud Computing Systems

Authors: Ebrahim Behrouzian Nejad, Rezvan Alipoor Sabzevari

Abstract:

Cloud computing systems are large-scale distributed systems, so that they focus more on large scale resource sharing, cooperation of several organizations and their use in new applications. One of the main challenges in this realm is resource allocation. There are many different ways to resource allocation in cloud computing. One of the common methods to resource allocation are economic methods. Among these methods, the auction-based method has greater prominence compared with Fixed-Price method. The double combinatorial auction is one of the proper ways of resource allocation in cloud computing. This method includes two phases: winner determination and resource allocation. In this paper a new method has been presented to determine winner in double combinatorial auction-based resource allocation using Imperialist Competitive Algorithm (ICA). The experimental results show that in our new proposed the number of winner users is higher than genetic algorithm. On other hand, in proposed algorithm, the number of winner providers is higher in genetic algorithm.

Keywords: cloud computing, resource allocation, double auction, winner determination

Procedia PDF Downloads 359
12307 Developing New Media Credibility Scale: A Multidimensional Perspective

Authors: Hanaa Farouk Saleh

Abstract:

The main purposes of this study are to develop a scale that reflects emerging theoretical understandings of new media credibility, based on the evolution of credibility studies in western researches, identification of the determinants of credibility in the media and its components by comparing traditional and new media credibility scales and building accumulative scale to test new media credibility. This approach was built on western researches using conceptualizations of media credibility, which focuses on four principal components: Source (journalist), message (article), medium (newspaper, radio, TV, web, etc.), and organization (owner of the medium), and adding user and cultural context as key components to assess new media credibility in particular. This study’s value lies in its contribution to the conceptualization and development of new media credibility through the creation of a theoretical measurement tool. Future studies should explore this scale to test new media credibility, which represents a promising new approach in the efforts to define and measure credibility of all media types.

Keywords: credibility scale, media credibility components, new media credibility scale, scale development

Procedia PDF Downloads 321
12306 Investigation of Graphene-MoS₂ Nanocomposite as Counter Electrode in Dye-Sensitized Solar Cells

Authors: Mozhgan Hosseinnezhad, Kamaladin Gharanjig, Mehdi Ghahari

Abstract:

Dye-sensitized solar cells are sustainable tool for generating electrical energy using sunlight. To develop this technology, obstacles such as cost and the use of expensive compounds must be overcome. Herein, we employed a MoS₂/graphene composite instead of platinum in the DSSCs. Platinum is an efficient and conventional counter electrode in the preparation of DSSCs, for this purpose, the effect of the presence of platinum electrode was also studied under similar conditions. The prepared nanocomposite product was checked by analysis methods to confirm the correctness of the construction and the desired structure. Finally, the DSSCs were fabricated using MoS₂/graphene composite, and to compare the results, the DSSCs were also prepared using platinum. The results showed that the prepared composite has a similar performance compared to platinum and can replace it.

Keywords: efficiency, dye-sensitized solar cell, nano-composite MoS₂, platinum free

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12305 Battery Control with Moving Average Algorithm to Smoothen the Intermittent Output Power of Photovoltaic Solar Power Plants in Off-Grid Configuration

Authors: Muhammad Gillfran Samual, Rinaldy Dalimi, Fauzan Hanif Jufri, Budi Sudiarto, Ismi Rosyiana Fitri

Abstract:

Solar energy is increasingly recognized as an important future energy source due to its abundant availability and renewable nature. However, the intermittent nature of solar energy can cause fluctuations in the electricity produced, making it difficult to guarantee a stable and reliable electricity supply. One solution that can be implemented is to use batteries in a photovoltaic solar power plant system with a Moving Average control algorithm, which can help smooth and reduce fluctuations in solar power output power. The parameter that can be adjusted in the Moving Average algorithm is the window size or the arithmetic average width of the photovoltaic output power over time. This research evaluates the effect of a change of window size parameter in the Moving Average algorithm on the resulting smoothed photovoltaic output power and the technical effects on batteries, i.e., power and energy usage. Based on the evaluation, it is found that the increase of window size parameter will slow down the response of photovoltaic output power to changes in irradiation and increase the smoothing quality of the intermittent photovoltaic output power. In addition, increasing the window size will reduce the maximum power received on the load side, and the amount of energy used by the battery during the power smoothing process will increase, which, in turn, increases the required battery capacity.

Keywords: battery, intermittent, moving average, photovoltaic, power smoothing

Procedia PDF Downloads 61
12304 Finite Element Modeling of Mass Transfer Phenomenon and Optimization of Process Parameters for Drying of Paddy in a Hybrid Solar Dryer

Authors: Aprajeeta Jha, Punyadarshini P. Tripathy

Abstract:

Drying technologies for various food processing operations shares an inevitable linkage with energy, cost and environmental sustainability. Hence, solar drying of food grains has become imperative choice to combat duo challenges of meeting high energy demand for drying and to address climate change scenario. But performance and reliability of solar dryers depend hugely on sunshine period, climatic conditions, therefore, offer a limited control over drying conditions and have lower efficiencies. Solar drying technology, supported by Photovoltaic (PV) power plant and hybrid type solar air collector can potentially overpower the disadvantages of solar dryers. For development of such robust hybrid dryers; to ensure quality and shelf-life of paddy grains the optimization of process parameter becomes extremely critical. Investigation of the moisture distribution profile within the grains becomes necessary in order to avoid over drying or under drying of food grains in hybrid solar dryer. Computational simulations based on finite element modeling can serve as potential tool in providing a better insight of moisture migration during drying process. Hence, present work aims at optimizing the process parameters and to develop a 3-dimensional (3D) finite element model (FEM) for predicting moisture profile in paddy during solar drying. COMSOL Multiphysics was employed to develop a 3D finite element model for predicting moisture profile. Furthermore, optimization of process parameters (power level, air velocity and moisture content) was done using response surface methodology in design expert software. 3D finite element model (FEM) for predicting moisture migration in single kernel for every time step has been developed and validated with experimental data. The mean absolute error (MAE), mean relative error (MRE) and standard error (SE) were found to be 0.003, 0.0531 and 0.0007, respectively, indicating close agreement of model with experimental results. Furthermore, optimized process parameters for drying paddy were found to be 700 W, 2.75 m/s at 13% (wb) with optimum temperature, milling yield and drying time of 42˚C, 62%, 86 min respectively, having desirability of 0.905. Above optimized conditions can be successfully used to dry paddy in PV integrated solar dryer in order to attain maximum uniformity, quality and yield of product. PV-integrated hybrid solar dryers can be employed as potential and cutting edge drying technology alternative for sustainable energy and food security.

Keywords: finite element modeling, moisture migration, paddy grain, process optimization, PV integrated hybrid solar dryer

Procedia PDF Downloads 150
12303 Performance Assessment Of An Existing Multi-effect Desalination System Driven By Solar Energy

Authors: B. Shahzamanian, S. Varga, D. C. Alarcón-Padilla

Abstract:

Desalination is considered the primary alternative to increase water supply for domestic, agricultural and industrial use. Sustainable desalination is only possible in places where renewable energy resources are available. Solar energy is the most relevant type of renewable energy to driving desalination systems since most of the areas suffering from water scarcity are characterized by a high amount of available solar radiation during the year. Multi-Effect Desalination (MED) technology integrated with solar thermal concentrators is a suitable combination for heat-driven desalination. It can also be coupled with thermal vapour compressors or absorption heat pumps to boost overall system performance. The most interesting advantage of MED is the suitability to be used with a transient source of energy like solar. An experimental study was carried out to assess the performance of the most important life-size multi-effect desalination plant driven by solar energy located in the Plataforma Solar de Almería (PSA). The MED plant is used as a reference in many studies regarding multi-effect distillation. The system consists of a 14-effect MED plant coupled with a double-effect absorption heat pump. The required thermal energy to run the desalination system is supplied by means of hot water generated from 60 static flat-plate solar collectors with a total aperture area of 606 m2. In order to compensate for the solar energy variation, a thermal storage system with two interconnected tanks and an overall volume of 40 m3 is coupled to the MED unit. The multi-effect distillation unit is built in a forward feed configuration, and the last effect is connected to a double-effect LiBr-H2O absorption heat pump. The heat pump requires steam at 180 ºC (10 bar a) that is supplied by a small-aperture parabolic trough solar field with a total aperture area of 230 m2. When needed, a gas boiler is used as an auxiliary heat source for operating the heat pump and the MED plant when solar energy is not available. A set of experiments was carried out for evaluating the impact of the heating water temperature (Th), top brine temperature (TBT) and temperature difference between effects (ΔT) on the performance ratio of the MED plant. The considered range for variation of Th, TBT and ΔT was 60-70°C, 54-63°C and 1.1-1.6°C, respectively. The performance ratio (PR), defined as kg of distillate produced for every 2326 kJ of thermal energy supplied to the MED system, was almost independent of the applied variables with a variation of less than 5% for all the cases. The maximum recorded PR was 12.4. The results indicated that the system demonstrated robustness for the whole range of operating conditions considered. Author gratitude is expressed to the PSA for providing access to its installations, the support of its scientific and technical staff, and the financial support of the SFERA-III project (Grant Agreement No 823802). Special thanks to the access provider staff members who ensured the access support.

Keywords: multi-effect distillation, performance ratio, robustness, solar energy

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12302 Scalable UI Test Automation for Large-scale Web Applications

Authors: Kuniaki Kudo, Raviraj Solanki, Kaushal Patel, Yash Virani

Abstract:

This research mainly concerns optimizing UI test automation for large-scale web applications. The test target application is the HHAexchange homecare management WEB application that seamlessly connects providers, state Medicaid programs, managed care organizations (MCOs), and caregivers through one platform with large-scale functionalities. This study focuses on user interface automation testing for the WEB application. The quality assurance team must execute many manual users interface test cases in the development process to confirm no regression bugs. The team automated 346 test cases; the UI automation test execution time was over 17 hours. The business requirement was reducing the execution time to release high-quality products quickly, and the quality assurance automation team modernized the test automation framework to optimize the execution time. The base of the WEB UI automation test environment is Selenium, and the test code is written in Python. Adopting a compilation language to write test code leads to an inefficient flow when introducing scalability into a traditional test automation environment. In order to efficiently introduce scalability into Test Automation, a scripting language was adopted. The scalability implementation is mainly implemented with AWS's serverless technology, an elastic container service. The definition of scalability here is the ability to automatically set up computers to test automation and increase or decrease the number of computers running those tests. This means the scalable mechanism can help test cases run parallelly. Then test execution time is dramatically decreased. Also, introducing scalable test automation is for more than just reducing test execution time. There is a possibility that some challenging bugs are detected by introducing scalable test automation, such as race conditions, Etc. since test cases can be executed at same timing. If API and Unit tests are implemented, the test strategies can be adopted more efficiently for this scalability testing. However, in WEB applications, as a practical matter, API and Unit testing cannot cover 100% functional testing since they do not reach front-end codes. This study applied a scalable UI automation testing strategy to the large-scale homecare management system. It confirmed the optimization of the test case execution time and the detection of a challenging bug. This study first describes the detailed architecture of the scalable test automation environment, then describes the actual performance reduction time and an example of challenging issue detection.

Keywords: aws, elastic container service, scalability, serverless, ui automation test

Procedia PDF Downloads 106
12301 Passive Solar-Driven Membrane Distiller for Desalination: Effect of Middle Layer Material and Thickness on Desalination Performance

Authors: Glebert C. Dadol, Camila Flor Y. Lobarbio, Noel Peter B. Tan

Abstract:

Water scarcity is a global problem. One of the promising solutions to this challenge is the use of membrane-based desalination technologies. In this study, a passive solar-driven membrane (PSDM) distillation was employed to test its desalination performance. The PSDM was fabricated using a TiNOX sheet solar absorber, cellulose-based hydrophilic top and bottom layers, and a middle layer. The effects of the middle layer material and thickness on the desalination performance in terms of distillate flow rate, productivity, and salinity were investigated. An air-gap screen mesh (2 mm, 4 mm, 6 mm thickness) and a hydrophobic PTFE membrane (0.3 mm thickness) were used as middle-layer materials. Saltwater input (35 g/L NaCl) was used for the PSDM distiller on a rooftop setting at the University of San Carlos, Cebu City, Philippines. The highest distillate flow rate and productivity of 1.08 L/m²-h and 1.47 L/kWh, respectively, were achieved using a 2 mm air-gap middle layer, but it also resulted in a high salinity of 25.20 g/L. Increasing the air gap lowered the salinity but also decreased the flow rate and productivity. The lowest salinity of 1.07 g/L was achieved using 6 mm air gap, but the flow rate and productivity were reduced to 0.08 L/m²-h and 0.17 L/kWh, respectively. The use of a hydrophobic PTFE membrane, on the other hand, did not offer a significant improvement in its performance. A PDSM distiller with a thick air gap as the middle layer can deliver a distillate with low salinity and is preferred over a thin hydrophobic PTFE membrane. Various modifications and optimizations to the distiller can be done to improve its performance further.

Keywords: desalination, membrane distillation, passive solar-driven membrane distiller, solar distillation

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12300 Investigation of the Material Behaviour of Polymeric Interlayers in Broken Laminated Glass

Authors: Martin Botz, Michael Kraus, Geralt Siebert

Abstract:

The use of laminated glass gains increasing importance in structural engineering. For safety reasons, at least two glass panes are laminated together with a polymeric interlayer. In case of breakage of one or all of the glass panes, the glass fragments are still connected to the interlayer due to adhesion forces and a certain residual load-bearing capacity is left in the system. Polymer interlayers used in the laminated glass show a viscoelastic material behavior, e.g. stresses and strains in the interlayer are dependent on load duration and temperature. In the intact stage only small strains appear in the interlayer, thus the material can be described in a linear way. In the broken stage, large strains can appear and a non-linear viscoelasticity material theory is necessary. Relaxation tests on two different types of polymeric interlayers are performed at different temperatures and strain amplitudes to determine the border to the non-linear material regime. Based on the small-scale specimen results further tests on broken laminated glass panes are conducted. So-called ‘through-crack-bending’ (TCB) tests are performed, in which the laminated glass has a defined crack pattern. The test set-up is realized in a way that one glass layer is still able to transfer compressive stresses but tensile stresses have to be transferred by the interlayer solely. The TCB-tests are also conducted under different temperatures but constant force (creep test). Aims of these experiments are to elaborate if the results of small-scale tests on the interlayer are transferable to a laminated glass system in the broken stage. In this study, limits of the applicability of linear-viscoelasticity are established in the context of two commercially available polymer-interlayers. Furthermore, it is shown that the results of small-scale tests agree to a certain degree to the results of the TCB large-scale experiments. In a future step, the results can be used to develop material models for the post breakage performance of laminated glass.

Keywords: glass breakage, laminated glass, relaxation test, viscoelasticity

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12299 Pragmatic Analysis of the Effectiveness of a Power Conditioning Device (DC-DC Converters) in a Simple Photovoltaics System

Authors: Asowata Osamede

Abstract:

Solar radiation provides the largest renewable energy potential on earth and photovoltaics (PV) are considered a promising technological solution to support the global transformation to a low-carbon economy and reduce dependence on fossil fuels. The aim of this paper is to evaluate the efficiency of power conditioning devices with a focus on the Buck and Boost DC-DC converters (12 V, 24 V and 48 V) in a basic off grid PV system with a varying load profile. This would assist in harnessing more of the available solar energy. The practical setup consists of a PV panel that is set to an orientation angle of 0º N, with corresponding tilt angles. Preliminary results, which include data analysis showing the power loss in the system and efficiency, indicate that the 12V DC-DC converter coupled with the load profile had the highest efficiency for a latitude of 26º S throughout the year.

Keywords: poly-crystalline PV panels, DC-DC converters, tilt and orientation angles, direct solar radiation, load profile

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12298 Low-Surface Roughness and High Optical Quality CdS Thin Film Deposited on Heated Substrate Using Room-Temperature Chemical Solution

Authors: A. Elsayed, M. H. Dewaidar, M. Ghali, M. Elkemary

Abstract:

The high production cost of the conventional solar cells requires the search for economic methods suitable for solar energy conversion. Cadmium Sulfide (CdS) is one of the most important semiconductors used in photovoltaics, especially in large area solar cells; and can be prepared in a thin film form by a wide variety of deposition techniques. The preparation techniques include vacuum evaporation, sputtering and molecular beam epitaxy. Other techniques, based on chemical solutions, are also used for depositing CdS films with dramatically low-cost compared to other vacuum-based methods. Although this technique is widely used during the last decades, due to simplicity and low-deposition temperature (~100°C), there is still a strong need for more information on the growth process and its relation with the quality of the deposited films. Here, we report on deposition of high-quality CdS thin films; with low-surface roughness ( < 3.0 nm) and sharp optical absorption edge; on low-temperature glass substrates (70°C) using a new method based on the room-temperature chemical solution. In this method, a mixture solution of cadmium acetate and thiourea at room temperature was used under special growth conditions for deposition of CdS films. X-ray diffraction (XRD) measurements were used to examine the crystal structure properties of the deposited CdS films. In addition, UV-VIS transmittance and low-temperature (4K) photoluminescence (PL) measurements were performed for quantifying optical properties of the deposited films. The deposited films show high optical quality as confirmed by observation of both, sharp edge in the transmittance spectra and strong PL intensity at room temperature. Furthermore, we found a strong effect of the growth conditions on the optical band gap of the deposited films; where remarkable red-shift in the absorption edge with temperature is clearly seen in both transmission and PL spectra. Such tuning of both optical band gap of the deposited CdS films can be utilized for tuning the electronic bands' alignments between CdS and other light-harvesting materials, like CuInGaSe or CdTe, for potential improvement in the efficiency of solar cells devices based on these heterostructures.

Keywords: chemical deposition, CdS, optical properties, surface, thin film

Procedia PDF Downloads 162
12297 Study of Heat Transfer in the Absorber Plates of a Flat-Plate Solar Collector Using Dual-Phase-Lag Model

Authors: Yu-Ching Yang, Haw-Long Lee, Win-Jin Chang

Abstract:

The present work numerically analyzes the transient heat transfer in the absorber plates of a flat-plate solar collector based on the dual-phase-lag (DPL) heat conduction model. An efficient numerical scheme involving the hybrid application of the Laplace transform and control volume methods is used to solve the linear hyperbolic heat conduction equation. This work also examines the effect of different medium parameters on the behavior of heat transfer. Results show that, while the heat-flux phase lag induces thermal waves in the medium, the temperature-gradient phase lag smoothens the thermal waves by promoting non-Fourier diffusion-like conduction into the medium.

Keywords: absorber plates, dual-phase-lag, non-Fourier, solar collector

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12296 An Approach to Determine Proper Daylighting Design Solution Considering Visual Comfort and Lighting Energy Efficiency in High-Rise Residential Building

Authors: Zehra Aybike Kılıç, Alpin Köknel Yener

Abstract:

Daylight is a powerful driver in terms of improving human health, enhancing productivity and creating sustainable solutions by minimizing energy demand. A proper daylighting system allows not only a pleasant and attractive visual and thermal environment, but also reduces lighting energy consumption and heating/cooling energy load with the optimization of aperture size, glazing type and solar control strategy, which are the major design parameters of daylighting system design. Particularly, in high-rise buildings where large openings that allow maximum daylight and view out are preferred, evaluation of daylight performance by considering the major parameters of the building envelope design becomes crucial in terms of ensuring occupants’ comfort and improving energy efficiency. Moreover, it is increasingly necessary to examine the daylighting design of high-rise residential buildings, considering the share of residential buildings in the construction sector, the duration of occupation and the changing space requirements. This study aims to identify a proper daylighting design solution considering window area, glazing type and solar control strategy for a high-residential building in terms of visual comfort and lighting energy efficiency. The dynamic simulations are carried out/conducted by DIVA for Rhino version 4.1.0.12. The results are evaluated with Daylight Autonomy (DA) to demonstrate daylight availability in the space and Daylight Glare Probability (DGP) to describe the visual comfort conditions related to glare. Furthermore, it is also analyzed that the lighting energy consumption occurred in each scenario to determine the optimum solution reducing lighting energy consumption by optimizing daylight performance. The results revealed that it is only possible that reduction in lighting energy consumption as well as providing visual comfort conditions in buildings with the proper daylighting design decision regarding glazing type, transparency ratio and solar control device.

Keywords: daylighting , glazing type, lighting energy efficiency, residential building, solar control strategy, visual comfort

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12295 Effect of Chlorophyll Concentration Variations from Extract of Papaya Leaves on Dye-Sensitized Solar Cell

Authors: Eka Maulana, Sholeh Hadi Pramono, Dody Fanditya, M. Julius

Abstract:

In this paper, extract of papaya leaves are used as a natural dye and combined by variations of solvent concentration applied on DSSC (Dye-Sensitized Solar Cell). Indonesian geographic located on the equator line occasions the magnitude of the potential to develop organic solar cells made from extracts of chlorophyll as a substitute for inorganic materials or synthetic dye on DSSC material. Dye serves as absorbing photons which are then converted into electrical energy. A conductive coated glass layer called TCO (Transparent Conductive Oxide) is used as a substrate of electrode. TiO2 nanoparticles as binding dye molecules, redox couple iodide/ tri-iodide as the electrolyte and carbon as the counter electrode in the DSSC are used. TiO2 nanoparticles, organic dyes, electrolytes and counter electrode are arranged and combined with the layered structure of the photo-catalyst absorption layer. Dye absorption measurements using a spectrophotometer at 200-800 nm light spectrum produces a total amount of chlorophyll 80.076 mg/l. The test cell at 7 watt LED light with 5000 lux luminescence were obtained Voc and Isc of 235.5 mV and 14 μA, respectively.

Keywords: DSSC (Dye-Sensitized Solar Cell), natural dye, chlorophyll, absorption

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12294 Modelling of Air-Cooled Adiabatic Membrane-Based Absorber for Absorption Chillers Using Low Temperature Solar Heat

Authors: M. Venegas, M. De Vega, N. García-Hernando

Abstract:

Absorption cooling chillers have received growing attention over the past few decades as they allow the use of low-grade heat to produce the cooling effect. The combination of this technology with solar thermal energy in the summer period can reduce the electricity consumption peak due to air-conditioning. One of the main components, the absorber, is designed for simultaneous heat and mass transfer. Usually, shell and tubes heat exchangers are used, which are large and heavy. Cooling water from a cooling tower is conventionally used to extract the heat released during the absorption and condensation processes. These are clear inconvenient for the generalization of the absorption technology use, limiting its benefits in the contribution to the reduction in CO2 emissions, particularly for the H2O-LiBr solution which can work with low heat temperature sources as provided by solar panels. In the present work a promising new technology is under study, consisting in the use of membrane contactors in adiabatic microchannel mass exchangers. The configuration here proposed consists in one or several modules (depending on the cooling capacity of the chiller) that contain two vapour channels, separated from the solution by adjacent microporous membranes. The solution is confined in rectangular microchannels. A plastic or synthetic wall separates the solution channels between them. The solution entering the absorber is previously subcooled using ambient air. In this way, the need for a cooling tower is avoided. A model of the configuration proposed is developed based on mass and energy balances and some correlations were selected to predict the heat and mass transfer coefficients. The concentration and temperatures along the channels cannot be explicitly determined from the set of equations obtained. For this reason, the equations were implemented in a computer code using Engineering Equation Solver software, EES™. With the aim of minimizing the absorber volume to reduce the size of absorption cooling chillers, the ratio between the cooling power of the chiller and the absorber volume (R) is calculated. Its variation is shown along the solution channels, allowing its optimization for selected operating conditions. For the case considered the solution channel length is recommended to be lower than 3 cm. Maximum values of R obtained in this work are higher than the ones found in optimized horizontal falling film absorbers using the same solution. Results obtained also show the variation of R and the chiller efficiency (COP) for different ambient temperatures and desorption temperatures typically obtained using flat plate solar collectors. The configuration proposed of adiabatic membrane-based absorber using ambient air to subcool the solution is a good technology to reduce the size of the absorption chillers, allowing the use of low temperature solar heat and avoiding the need for cooling towers.

Keywords: adiabatic absorption, air-cooled, membrane, solar thermal energy

Procedia PDF Downloads 285
12293 Economical Transformer Selection Implementing Service Lifetime Cost

Authors: Bonginkosi A. Thango, Jacobus A. Jordaan, Agha F. Nnachi

Abstract:

In this day and age, there is a proliferate concern from all governments across the globe to barricade the environment from greenhouse gases, which absorb infrared radiation. As a result, solar photovoltaic (PV) electricity has been an expeditiously growing renewable energy source and will eventually undertake a prominent role in the global energy generation. The selection and purchasing of energy-efficient transformers that meet the operational requirements of the solar photovoltaic energy generation plants then become a part of the Independent Power Producers (IPP’s) investment plan of action. Taking these into account, this paper proposes a procedure that put into effect the intricate financial analysis necessitated to precisely evaluate the transformer service lifetime no-load and load loss factors. This procedure correctly set forth the transformer service lifetime loss factors as a result of a solar PV plant’s sporadic generation profile and related levelized costs of electricity into the computation of the transformer’s total ownership cost. The results are then critically compared with the conventional transformer total ownership cost unaccompanied by the emission costs, and demonstrate the significance of the sporadic energy generation nature of the solar PV plant on the total ownership cost. The findings indicate that the latter play a crucial role for developers and Independent Power Producers (IPP’s) in making the purchase decision during a tender bid where competing offers from different transformer manufactures are evaluated. Additionally, the susceptibility analysis of different factors engrossed in the transformer service lifetime cost is carried out; factors including the levelized cost of electricity, solar PV plant’s generation modes, and the loading profile are examined.

Keywords: solar photovoltaic plant, transformer, total ownership cost, loss factors

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12292 Climate Adaptive Building Shells for Plus-Energy-Buildings, Designed on Bionic Principles

Authors: Andreas Hammer

Abstract:

Six peculiar architecture designs from the Frankfurt University will be discussed within this paper and their future potential of the adaptable and solar thin-film sheets implemented facades will be shown acting and reacting on climate/solar changes of their specific sites. The different aspects, as well as limitations with regard to technical and functional restrictions, will be named. The design process for a “multi-purpose building”, a “high-rise building refurbishment” and a “biker’s lodge” on the river Rheine valley, has been critically outlined and developed step by step from an international studentship towards an overall energy strategy, that firstly had to push the design to a plus-energy building and secondly had to incorporate bionic aspects into the building skins design. Both main parameters needed to be reviewed and refined during the whole design process. Various basic bionic approaches have been given [e.g. solar ivyᵀᴹ, flectofinᵀᴹ or hygroskinᵀᴹ, which were to experiment with, regarding the use of bendable photovoltaic thin film elements being parts of a hybrid, kinetic façade system.

Keywords: bionic and bioclimatic design, climate adaptive building shells [CABS], energy-strategy, harvesting façade, high-efficiency building skin, photovoltaic in building skins, plus-energy-buildings, solar gain, sustainable building concept

Procedia PDF Downloads 430
12291 Highway Lighting of the 21st Century is Smart, but is it Cost Efficient?

Authors: Saurabh Gupta, Vanshdeep Parmar, Sri Harsha Reddy Yelly, Michele Baker, Elizabeth Bigler, Kunhee Choi

Abstract:

It is known that the adoption of solar powered LED highway lighting systems or sensory LED highway lighting systems can dramatically reduce energy consumption by 55 percent when compared to conventional on-grid High Pressure Sodium (HPS) lamps that are widely applied to most highways. However, an initial high installation cost for building the infrastructure of solar photovoltaic devices hampers a wider adoption of such technologies. This research aims to examine currently available state-of-the-art solar photovoltaic and sensory technologies, identify major obstacles, and analyze each technology to create a benchmarking metrics from the benefit-cost analysis perspective. The on-grid HPS lighting systems will serve as the baseline for this study to compare it with other lighting alternatives such as solar and sensory LED lighting systems. This research will test the validity of the research hypothesis that alternative LED lighting systems produce more favorable benefit-cost ratios and the added initial investment costs are recouped by the savings in the operation and maintenance cost. The payback period of the excess investment and projected savings over the life-cycle of the selected lighting systems will be analyzed by utilizing the concept of Net Present Value (NPV). Researchers believe that if this study validates the research hypothesis, it can promote a wider adoption of alternative lighting systems that will eventually save millions of taxpayer dollars in the long-run.

Keywords: lighting systems, sensory and solar PV, benefit cost analysis, net present value

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12290 Impacts of Financial Development and Operational Scale on Bank Efficiencies in Taiwan

Authors: Ying-Hsiu Chen, Pao-Peng Hsu

Abstract:

This paper adopts a two-stage data envelopment analysis to explore the impacts of financial development and bank operational scale on bank efficiencies. The sample comprises of unbalanced panel data of 32 Taiwanese enlisted in domestic commercial banks over the period 1998 to 2013. Empirical results show that technical efficiency is positively related to financial development, whereas the effect of financial development on scale efficiency is insignificant. The effect of operational scale exerts a significantly positive effect on bank efficiencies, but the gain of efficiency is decreased gradually when operational scale increases. Furthermore, increase in capital adequacy ratio and market power of banks leads to a growth of bank efficiencies.

Keywords: financial development, operational scale, efficiency, DEA

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12289 Support Vector Regression Combined with Different Optimization Algorithms to Predict Global Solar Radiation on Horizontal Surfaces in Algeria

Authors: Laidi Maamar, Achwak Madani, Abdellah El Ahdj Abdellah

Abstract:

The aim of this work is to use Support Vector regression (SVR) combined with dragonfly, firefly, Bee Colony and particle swarm Optimization algorithm to predict global solar radiation on horizontal surfaces in some cities in Algeria. Combining these optimization algorithms with SVR aims principally to enhance accuracy by fine-tuning the parameters, speeding up the convergence of the SVR model, and exploring a larger search space efficiently; these parameters are the regularization parameter (C), kernel parameters, and epsilon parameter. By doing so, the aim is to improve the generalization and predictive accuracy of the SVR model. Overall, the aim is to leverage the strengths of both SVR and optimization algorithms to create a more powerful and effective regression model for various cities and under different climate conditions. Results demonstrate close agreement between predicted and measured data in terms of different metrics. In summary, SVM has proven to be a valuable tool in modeling global solar radiation, offering accurate predictions and demonstrating versatility when combined with other algorithms or used in hybrid forecasting models.

Keywords: support vector regression (SVR), optimization algorithms, global solar radiation prediction, hybrid forecasting models

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12288 Estimating Future Solar Potential in Evolving High-Density Urban Areas for the Mid-Latitude City of Mendoza, Argentina

Authors: Mariela Edith Arboit

Abstract:

The main goal of the project is to explore the evolution possibilities of the morphological indicators of the built environment, including those resulting from progressive soil occupation, due to the relentless growth of the city’s population and subsequent increase in building density and solar access reduction per built unit. Two alternative normative proposals, Conventional Proposal (CP) and Alternative Proposal (AP), are compared. In addition, temporal scenarios of the city’s evolution process are analyzed, starting from the reference situation of existing, high-density built-up areas, and simulating their possible morphological outcomes on theoretical medium (30 yr.) and long (60 yr.) terms, as a result of the massive implementation of either regulation in the long run. The results obtained demonstrate that the Alternative Proposal (AP) presents higher mean values of predicted solar potential expressed by the Volumetric Insolation Factor total (VIFtot) for both time periods and services. Regarding environmental aspects, the different impacts of either alternative on the urban landscape quality seem to favor the AP proposal. Its deserved detailed assessment is also presently being developed through a quanti-qualitative methodology.

Keywords: building morphology, environmental quality, solar energy, urban sustainability

Procedia PDF Downloads 157