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Photovoltaic Greenhouses: Comparison of Optical and Thermal Behaviour for Energy Savings
Maurizio Carlini,Tommaso Honorati,Sonia Castellucci
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/743764
Abstract: The production of energy from renewable sources, the diversification of the productive activities, and the development of photovoltaic technology and integrated systems have led to the development of solar greenhouses. The interest of the developers and designers is now to seek new approaches to combine the electricity and food production optimally. The interaction of factors as outside local climate, exposure, slope, soil, altitude, wind conditions, structural materials, or cultivated plant species, influences greatly the energy balance. This paper illustrates the comparison of optical and thermal behavior of a solar greenhouse and a similar glass greenhouse, devoted to the production of soil-less tomatoes in three different Italian areas, with computational aspects and methods of the TRNSYS simulation. Values of climatic parameters are obtained as a responce for the feasibility of the cultivation under PV modules. The results show energy savings both for heating and cooling due to PV panels, adding a new reason for the realization of these systems.
HAGYMáSSY Zoltán,FóRIáN Sándor
Debreceni M?szaki K?zlemények , 2009,
Abstract: Information’s are given about that a solar energy power plant was developed and experiences of operating photovoltaic PV-panels in the University of Debrecen, Department of Agricultural Machinery. The electricity performance of the incorporated PV-panels (Kyocera, Dunasolar, and Siemens) are 8, 64 kW. There are 3 reasons operating the PV-panels and inverters:1. In the field of education: introduced the solar panels and PV-panels and inverters.2. In the field of research work: measuring and calculating the coefficient of efficiency, exposure metering, economical calculations. 3. For exhibition: demonstration and propagation the renewed energy.
Simulation of Fatigue Crack Growth in Integrally Stiffened Panels Under the Constant Amplitude and Spectrum Loadin
Petr Augustin
Fatigue of Aircraft Structures , 2009, DOI: 10.2478/v10164-010-0001-2
Abstract: The paper describes methodology of numerical simulation of fatigue crack growth and its application on integrally stiffened panels made of 2024-T351 aluminium alloy using high speed cutting technique. Presented approach for crack growth simulation starts by the calculation of stress intensity factor function from finite element results obtained using MSC. Patran/Nastran. Subsequent crack growth analysis is done in NASGRO and uses description of crack growth rates either by the Forman-Newman-de Koning relationship or by the table lookup form. Three crack growth models were applied for spectrum loading: non-interaction, Willenborg and Strip Yield model. Relatively large experimental program comprising both the constant amplitude and spectrum tests on integral panels and CCT specimens was undertaken at the Institute of Aerospace Engineering laboratory in order to acquire crack growth rate data and enable verification of simulations. First analyses and verification tests of panels were performed under the constant amplitude loading. For predictions of crack growth using the spectrum loading a load sequence representing service loading of the transport airplane wing was prepared. Applied load spectrum was measured on B737 airplane within the joint FAA/NASA collection program. The load sequence is composed of 10 flight types with different severity analogous to the standardized load sequence TWIST. Before application on the stiffened panels a calculation of crack growth under the spectrum loading was performed for simple CCT specimen geometry. The paper finally presents comparison of simulations of fatigue crack propagation in two-stringer stiffened panel under the spectrum loading with verification test carried out in the IAE lab. The work was performed within the scope of the 6th Framework Programme project DaToN - Innovative Fatigue and Damage Tolerance Methods for the Application of New Structural Concepts.
GIS Based Management System for Photovoltaic Panels  [PDF]
Muhammad Luqman, Sajid Rashid Ahmad, Samiullah Khan, Farkhanda Akmal, Usman Ahmad, Ahmad Raza, Muhammad Nawaz, Asif Javed, Hamad Ali
Journal of Geographic Information System (JGIS) , 2015, DOI: 10.4236/jgis.2015.74031
Abstract: This paper provides a proposal of implementation of latest technologies in photovoltaic installation and management system. Punjab Government Cooperative Housing Society was selected to find out suitability for photovoltaic installation and its management after that. Google Earth imagery and scanned maps were selected for the preparation of spatial and attribute data of buildings in the study area by using ArcGIS software. In first stage data were digitized and suitability and potential for each building were estimated. In second stage all the tabular data which consisted of owner information, panel information, its potential and location were linked to each other for management purpose. Selected area for solar panels installation was linked to building information for query and visualization.
HUSI Géza,BARTHA István,TóTH János
Debreceni M?szaki K?zlemények , 2009,
Abstract: At the Faculty of Engineering University of Debrecen related to the building integrated photovoltaic systems research work is performed. In this research activity our partner is Yingli Green Energy Holding Company Limited. In summer 2009 we had the opportunity to visit the factory of this company placed in Baoding, near Beijing. During this visit we got familiarized with the most advanced manufacturing technology of photovoltaic panels. This paper presents the main phases of this process, enhancing the building integrated panels.
The Disagreement between Anisotropic-Isotropic Diffuse Solar Radiation Models as a Function of Solar Declination: Computing the Optimum Tilt Angle of Solar Panels in the Area of Southern-Italy  [PDF]
Emanuele Calabrò
Smart Grid and Renewable Energy (SGRE) , 2012, DOI: 10.4236/sgre.2012.34035
Abstract: In this paper a simulation to maximize the global solar radiation on a sloped collecting surface was applied to typical latitudes in the area of southern Italy, to calculate the optimum tilt angle of solar panels on building structures or large photovoltaic power plants located in that geographical area. Indeed, the area of southern Italy and in particular Sicily and Calabria are the top of European locations for acquiring solar energy. Some models of diffuse solar irradiance were taken into account to determine panels inclinations that maximized the impinging solar radiation by means of global horizontal solar radiation data provided from the Italian Institute of ENEA (Italy). An algorithm was used for the simulation providing a set of tilt angles for each latitude. The optimum tilt angle values obtained from the simulation resulted to be strictly related to the model of diffuse solar radiation that was used. Indeed, the disagreement between the values obtained using anisotropic models of diffuse solar radiation and those obtained from the isotropic model resulted to decrease significantly with increasing solar declination, showing that the isotropic model can be reliable only in summer months.
屋面光伏板风荷载特性数值分析 Numerical analysis of wind load characteristics of photovoltaic panels mounted on a roof
Numerical analysis of wind load characteristics of photovoltaic panels mounted on a roof

- , 2016, DOI: 10.7511/jslx201605005
Abstract: 风荷载在屋面光伏阵列结构体系设计中起控制作用。采用计算风工程的方法分析讨论了屋面光伏板的风荷载特性。数值算法采用分离涡模拟方法。数值计算结果与现有风洞实验数据的比较,验证了本文方法的正确性。考虑影响光伏板风荷载的因素主要有光伏板在屋面上的安装位置、安装倾角、光伏阵列之间的距离和风向等。计算结果表明,屋面处脱落的涡对安装在不同位置的光伏阵列风荷载的影响较明显。当倾角由15°增加到45°时,电池板受到的风荷载随着倾角的增加而增大。在一定阵列间距范围内,光伏板风荷载主要表现为前排对下游光伏板的遮挡影响。本文方法与结果能为屋面光伏建筑结构设计提供重要参考。
Wind loads play a major role in designing of structural systems for roof-mounted photovoltaic panels.The detached eddy simulation method is employed in this study.Computational wind engineering method has been performed to evaluate wind loads on photovoltaic panels mounted on the roof.The simulation results have been compared and validated with a wind tunnel experimental measurements.The main parameters affected wind loads acting on photovoltaic array panels,such as panel tilt angles,the installation locations on the roof,distance between arrays,and wind directions,were considered.The numerical results showed that the mean values of the uplift wind loads increase with increasing in tilt angle from 15° to 40°.The numerical data demonstrated that wind loads on the photovoltaic panel were substantially affected by the vortices generated by building roof edges.The study also showed that sheltering effect caused by upwind photovoltaic panels reduced the wind loads on the adjacent panels when they were arranged in tandem.The proposed numerical method and the calculation results could provide an important reference for the design of photovoltaic array supporting systems,which are mounted on the roof,and the building structures.
Monitoring of degradation of photovoltaic panels using infrared method  [PDF]
Zdeněk Dostál,Miroslav ?ulík,Marcela Ko??ová,Pavel ?imon
Acta Montanistica Slovaca , 2010,
Abstract: Monitoring of solar panels is important in order to ensure optimal performance of solar panels. Their properties are subjectto change due to aging, weather effects and exposure to environment. Infrared camera provides monitoring of degradation of solarpanels. Similarly, thermal camera can detect errors in panels, which occured during production or assembly.
Optimum Tilt Angles for Photovoltaic Panels during Winter Months in the Vaal Triangle, South Africa  [PDF]
Osamede Asowata, James Swart, Christo Pienaar
Smart Grid and Renewable Energy (SGRE) , 2012, DOI: 10.4236/sgre.2012.32017
Abstract: Optimizing the output power of a photovoltaic panel improves the efficiency of a solar driven energy system. The maximum output power of a photovoltaic panel depends on atmospheric conditions, such as (direct solar radiation, air pollution and cloud movements), load profile and the tilt and orientation angles. This paper describes an experimental analysis of maximizing output power of a photovoltaic panel, based on the use of existing equations of tilt angles derived from mathematical models and simulation packages. Power regulation is achieved by the use of a DC-DC converter, a fixed load resistance and a single photovoltaic panel. A data logger is used to make repeated measurements which ensure reliability of the results. The results of the paper were taken over a four month period from April through July. The photovoltaic panel was set to an orientation angle of 0? with tilt angles of 16?, 26? and 36?. Preliminary results indicate that tilt angles between 26? and 36? provide optimum photovoltaic output power for winter months in South Africa.
Utilization of photovoltaic panels in urban build-up areas grid on
Tau? Peter,Rybár Radim
Acta Montanistica Slovaca , 2001,
Abstract: Photovoltaic systems belong to the most perspective alternative sources of energy. We expect that during a relatively short period of time, the photovoltaic systems will slowly cover 5 to 10 % of the whole consumption of the electricity. One of the conditions of integration to European Community is the rising of the part of alternative sources in the production of energy. Besides another technologies, it s also possible to reach it with an installation of the photovoltaic systems in already-existed building-up area. The photovoltaic systems Grid on are used especially in places with the advanced net of electric lines in big cities. The invertors developed especially for the photovoltaic systems "Grid on" have the effeciency higher than 90 % and they are absolute safe against the bias voltage.From the entire number of days of an year in Slovakia the sun shines from 1300 to 2200 hours, in Ko ice it s 2100 hours. An average amount of energy falling down by one day is 3,3 kW.h.m-2. An average effective power of one m2 of the photovoltaic panels is 110 W.m-2 of the standard illuminance 1000 W.m-2 and the solar spectrum AM 1,5. Annually it s possible to make from the photovoltaic panel (1 m2) 120,45 kW.h. Average amount of the solar energy shape to the south-orient area in Ko ice is 101,5 kW.h.m-2. In Ko ice is an ideal inclination of the absorption area of the photovoltaic panels from horizontal plains from 58° to 65° for the year-around operation. At optimal conditions it s possible by integrating photovoltaic panels with the construction of the balcony barrier from one block of flats about 10 MW.h per year. If we utilise the all areas applicable for the installation of photovoltaic panels (building exteriors, roofs, shady component,..), we able to cast about a few multiple of these value just for one block of flat.Today, the cost of the photovoltaic systems is many times higher than the cost of the electric energy. But the cost consequently a new technology of production of the primary materials is allways falling.
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