scholarly journals A Trial to Predict the Diurnal Global Solar Irradiance Received On A Horizontal Plane for Clear Days in Terms of The Solar Angles.

2019 ◽  
Vol 16 (1) ◽  
pp. 344-354
Author(s):  
Samia Sayed Shaban
Keyword(s):  
Distribution Function ◽  
Solar Energy ◽  
Solar Irradiance ◽  
Horizontal Plane ◽  
Present Model ◽  
Meteorological Data ◽  
General Distribution ◽  
Symmetrical Distribution ◽  
Maximum Value ◽  
Length Of The Day

A general distribution function is suggested to predict both symmetrical and asymmetric diurnal global solar irradiance q (t) W/m2 received on a horizontal surface, where “t” is the local day time "h" .The distribution is given in terms of well-established parameters, namely: td :- the length of the solar day expressed in term of the solar angles. tmax :- the time of the day at which the irradiance reaches its maximum value qmax W/m2 for symmetrical distribution  tmax =   i.e.  it occurs at the midday time. td , tmax and qmax are taken as parameters. The suggested expression can be easily integrated along the length of the day time. This gives the daily totals of the received solar energy per unit horizontal area.This is of vital technical importance for solar energy exploitations and applications.  Comparison between computed according to the present model and published experimental meteorological data in Barcelona (Spain), Hong Kong (China), Jeddah and Makah (Saudi Arabia) is given as illustrative examples. Comparison with the published trials for the same locations is also clarified. The introduced model itself gives good fitting for the intermediate interval points of the local day time which is the more effective region.

scholarly journals Spillovers and R&D Incentive under Incomplete Information

2018 ◽  
Vol 6 (1-2) ◽  
pp. 50-65 ◽  
Author(s):  
Rittwik Chatterjee ◽  
Srobonti Chattopadhyay ◽  
Tarun Kabiraj
Keyword(s):  
Distribution Function ◽  
Incomplete Information ◽  
Private Information ◽  
Complete Information ◽  
Jel Classification ◽  
General Distribution ◽  
Two Stage ◽  
Stage Game ◽  
Alternative Scenarios

Spillovers of R&D outcome affect the R&D decision of a firm. The present paper discusses the R&D incentives of a firm when the extent of R&D spillover is private information to each firm. We construct a two-stage game involving two firms when the firms first decide simultaneously whether to invest in R&D or not, then they compete in quantity. Assuming general distribution function of firm types we compare R&D incentives of firms under alternative scenarios based on different informational structures. The paper shows that while R&D spillovers reduce R&D incentives under complete information unambiguously, however, it can be larger under incomplete information. JEL Classification: D43, D82, L13, O31

scholarly journals Economical and efficient technique for a static localized maximum sun lux determination

2019 ◽  
Vol 10 (2) ◽  
pp. 777
Author(s):  
Ahmed H. Ali ◽  
Adel S. Nada ◽  
Ahmed S. Shalaby
Keyword(s):  
Solar Cell ◽  
Solar Energy ◽  
Solar Irradiance ◽  
Field Measurements ◽  
Fine Tuning ◽  
Efficient Technique ◽  
Irradiance Measurement ◽  
Novel Technique ◽  
Site Field ◽  
Optimal Values

<span>Solar energy is one of the most promising renewable sources that is currently being used worldwide to contribute for meeting rising demands. In this paper solar irradiance measurement will experimentally carried out in two different regions in Egypt; Cairo and Luxor cities. This paper proposes a simple solar lux measurement using a light dependent resistor (LDR) with an arduino kit. This technique is based on two approaches which are coarse and fine maximum sun lux determination. This is based on the predetermined 26<sup>0</sup> vertical slop of the LDR. Coarse tuning determines one of the reach sun lux quarter (90<sup>0</sup>) of horizontal quad. The fine tuning allocates the optimized 10<sup>0</sup> in which; the maximum sun lux can be obtained. The optimal values of sun lux were found between the (90<sup>o</sup>–180<sup>o</sup>) quarter. This study confirms that the narrow ten degrees (95<sup>o</sup>-105<sup>o</sup>) are the optimized static sun lux extraction for the two site field measurements. This novel technique can be used for locating the angle of best installations for the solar cell at which maximum solar energy can be extracted. </span>

scholarly journals CONSTRUCCIÓN DE UNA VIVIENDA SOLAR EN BASE A LAS PROPIEDADES TERMOFISICAS Y EVALUACIÓN EXPERIMENTAL DE SU CONFORT TÉRMICO EN ILAVE

2014 ◽  
Vol 16 (01) ◽  
Author(s):  
ARTURO FLORES CONDORI
Keyword(s):  
Relative Humidity ◽  
Solar Energy ◽  
Thermal Comfort ◽  
Thermophysical Properties ◽  
Experimental Evaluation ◽  
Meteorological Data ◽  
Thermal Inertia ◽  
Living Condition ◽  
Simulation Software ◽  
Experimental Structure

<h4 class="text-primary">Resumen</h4><p style="text-align: justify;">El presente artículo consistió en la construcción de una vivienda solar pasivo a base de propiedades termofísicas (Conductividad térmica, calor específico, difusividad térmica y inercia térmica) y desarrollar una evaluación experimental del rendimiento térmico aportado por los elementos constructivos, en una comunidad rural Colloco - Ilave, provisto de adecuado aislamiento térmico en la envolvente (doble pared de adobe, en el cielo raso: paja­carrizo-yeso y en el piso: tierra apisonada-cama de piedra-plástico-paja y totora), ubicación, la orientación y un sistema de acumulación de energía adecuadamente diseñada a base a encapsulado de piedras andesitas porosas y de totora. La distribución de energía calorífica almacenada fue primordial al ambiente dormitorio que esto permite el aprovechamiento de la energía solar para lograr que la temperatura al interior de la vivienda sea más confortable. Se realizó el análisis del comportamiento térmico de la vivienda construida y la vivienda rural típica, para lo cual se tomaron los datos meteorológicos de la zona (temperatura, humedad relativa, velocidad del viento y radiación solar), también se registraron la temperatura y humedad relativa del aire en el ambiente interior y exterior de las viviendas desde 19 de junio al 02 de julio del 2013. Obteniéndose en la vivienda construida las temperaturas máximas y mínimas de 15.85ºC y 11.88ºC respectivamente. Según la evaluación de la vivienda construida se aprecia un incremento de temperatura mínimo de 6.26°C, respecto a la vivienda típica. Para validar estos resultados experimentales, se ha utilizado el programa de simulación térmica EnergyPlus para los datos meteorológicos de la zona (3 868 msnm), comprobándose por el método correlativo, el factor de correlación fue r=0.92575. Este incremento de la temperatura en el interior de la vivienda construida contribuye alcanzar un confort térmico, permitiendo una condición de vida saludable para el poblador rural.</p><p><strong>PALABRAS CLAVE: </strong>* confort térmico * energía solar * propiedades termofísica * simulación térmica</p><h4 class="text-primary">ABSTRACT</h4><p><strong>CONSTRUCTION OF A SOLAR DWELLING BASED ON THERMOPHYSICAL PROPERTIES AND EXPERIMENTAL EVALUATION OF THERMAL COMFORT - ILAVE, PUNO - PERU»</strong></p><p style="text-align: justify;">The present article consists in the construction of a passive solar house based on the study of thermophysical properties (thermal conductivity, specific heat, thermal diffusivity and thermal inertia). We developed an experimental evaluation of the thermal efficiency contributed by different constructive materials, In the rural community of Colloco - Ilave. Once adequate thermal insulation was provided in the enveloping surface (double wall construction of sun-dried adobe brick, a false ceiling with: straw, bamboo and plaster. In the floor: tamped soil, stone bed, plastic, straw and totora reed). Location and position of the solar home in coordination with an energy accumulation system adequately designed with an encapsulation of porous Andesitic stones and Totora reed. Distribution of the stored thermal energy was directed primarily to the main bedroom, this enabled adequate use of solar energy in order to achieve a comfortable temperature within the dwelling. We analyzed the thermal behavior of both this experimental structure and that of a common rural dwelling; taking the interior and exterior meteorological readings found in the two dwelling types. (temperature, relative humidity, wind velocity and solar radiation). Between June 19th and July 2nd, the temperature and relative humidity of the interior of the experimental structure measured a max. of 15.85ºC (60.53ºF) and 11.88ºC (53.384ºF) respectively. According to a general evaluation of the experimental structure, there was a temperature increment of 6.26°C (=¿?ºF) compared to the average temperature of a normal dwelling. In order to confirm these experimental results we used the thermic simulation software EnergyPlus, entering the meteorological data of the area (3,868 meters above sea level=12690.3 ft.) using the correlative method and a correlative factor of r=0.92575. This higher temperature inside of the experimental structure contributes to attaining a thermic comfort allowing for a healthy living condition for the rural inhabitant.</p><p><strong>KEY WORDS: </strong>* thermal comfort * solar energy * thermophysical properties * thermal simulation</p>

Assessment of a newly developed short-term forecasting system (nextSENSE) of Downwelling Surface Solar Irradiance (DSSI) and validation with ground-based measurements

2021 ◽  
Author(s):  
Kyriakoula Papachristopoulou ◽  
Ilias Fountoulakis ◽  
Panagiotis Kosmopoulos ◽  
Dimitris Kouroutsidis ◽  
Panagiotis I. Raptis ◽  
...  
Keyword(s):  
Solar Energy ◽  
Solar Irradiance ◽  
Surface Radiation ◽  
Solar Irradiation ◽  
Short Term ◽  
Large Spatial Scale ◽  
Infrared Imager ◽  
Flow Motion ◽  
Forecasting System ◽  
Short Term Forecasting

&lt;p&gt;Monitoring and forecasting cloud coverage is crucial for nowcasting and forecasting of solar irradiance reaching the earth surface, and it&amp;#8217;s a powerful tool for solar energy exploitation systems.&lt;/p&gt;&lt;p&gt;In this study, we focused on the assessment of a newly developed short-term (up to 3h) forecasting system of Downwelling Surface Solar Irradiation (DSSI) in a large spatial scale (Europe and North Africa). This system forecasts the future cloud position by calculating Cloud Motion Vectors (CMV) using Cloud Optical Thickness (COT) data derived from multispectral images from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard the Meteosat Second Generation (MSG) satellite and an optical flow motion estimation technique from the computer vision community. Using as input consecutive COT images, CMVs are calculated and cloud propagation is performed by applying them to the latest COT image. Using the predicted COT images, forecasted DSSI is calculated using Fast Radiative Transfer Models (FRTM) in high spatial (5 km over nadir) and temporal resolution (15 min time intervals intervals).&lt;/p&gt;&lt;p&gt;A first evaluation of predicted COT has been conducted, by comparing the predicted cloud parameter of COT with real observed values derived by the MSG/SEVIRI. Here, the DSSI is validated against ground-based measurements from three Baseline Surface Radiation Network (BSRN) stations, for the year 2017. Also, a sensitivity analysis of the effect on DSSI for different cloud and aerosol conditions is performed, to ensure reliability under different sky and climatological conditions.&lt;/p&gt;&lt;p&gt;The DSSI short-term forecasting system proposed, complements the existing short-term forecasting techniques and it is suitable for operational deployment of solar energy related systems&lt;/p&gt;&lt;p&gt;Acknowledgements&lt;/p&gt;&lt;p&gt;This study was funded by the EuroGEO e-shape (grant agreement No 820852).&lt;/p&gt;

Artificial Intelligence Techniques for Solar Energy and Photovoltaic Applications

2013 ◽  
pp. 376-436 ◽  
Author(s):  
Radian Belu
Keyword(s):  
Artificial Intelligence ◽  
Solar Radiation ◽  
Solar Energy ◽  
Meteorological Data ◽  
Energy Systems ◽  
Poor Quality ◽  
Quality Of Data ◽  
Information Patterns ◽  
Time Requirements

Artificial intelligence (AI) techniques play an important role in modeling, analysis, and prediction of the performance and control of renewable energy. The algorithms employed to model, control, or to predict performances of the energy systems are complicated involving differential equations, large computer power, and time requirements. Instead of complex rules and mathematical routines, AI techniques are able to learn the key information patterns within a multidimensional information domain. Design, control, and operation of solar energy systems require long-term series of meteorological data such as solar radiation, temperature, or wind data. Such long-term measurements are often non-existent for most of the interest locations or, wherever they are available, they suffer of a number of shortcomings (e.g. poor quality of data, insufficient long series, etc.). To overcome these problems AI techniques appear to be one of the strongest candidates. The chapter provides an overview of commonly used AI methodologies in solar energy, with a special emphasis on neural networks, fuzzy logic, and genetic algorithms. Selected AI applications to solar energy are outlined in this chapter. In particular, methods using the AI approach for the following applications are discussed: prediction and modeling of solar radiation, seizing, performances, and controls of the solar photovoltaic (PV) systems.

scholarly journals Models and hierarchical methodologies for evaluating solar energy availability under different sky conditions toward enhancing concentrating solar collectors use: Texas as a case study

2019 ◽  
Vol 11 (2) ◽  
pp. 177-205 ◽  
Author(s):  
Fadhil Y. Al-Aboosi
Keyword(s):  
Solar Energy ◽  
Solar Irradiance ◽  
Correlation Coefficients ◽  
Regression Equations ◽  
Direct Normal Irradiance ◽  
Energy Conversion Systems ◽  
Irradiance Data ◽  
Photovoltaic Plants ◽  
Sky Conditions

AbstractThe precise estimation of solar radiation data is substantial in the long-term evaluation for the techno-economic performance of solar energy conversion systems (e.g., concentrated solar thermal collectors and photovoltaic plants) for each site around the world, particularly, direct normal irradiance which is utilized commonly in designing solar concentrated collectors. However, the lack of direct normal irradiance data comparing to global and diffuse horizontal irradiance data and the high cost of measurement equipment represent significant challenges for exploiting and managing solar energy. Consequently, this study was performed to develop two hierarchical methodologies by using various models, empirical correlations and regression equations to estimate hourly solar irradiance data for various worldwide locations (using new correlation coefficients) and different sky conditions (using cloud cover range). Additionally, the preliminary assessment for the potential of solar energy in the selected region was carried out by developing a comprehensive analysis for the solar irradiance data and the clearness index to make a proper decision for the capability of utilizing solar energy technologies. A case study for the San Antonio region in Texas was selected to demonstrate the accuracy of the proposed methodologies for estimating hourly direct normal irradiance and monthly average hourly direct normal irradiance data at this region. The estimated data show a good accuracy comparing with measured solar data by using locally adjusted coefficients and different statistical indicators. Furthermore, the obtained results show that the selected region is unequivocally amenable to harnessing solar energy as the prime source of energy by utilizing concentrating and non-concentrating solar energy systems.

Asymptotic behavior of Hill's estimate and applications

1986 ◽  
Vol 23 (04) ◽  
pp. 922-936
Author(s):  
Gane Samb Lo
Keyword(s):  
Distribution Function ◽  
Asymptotic Behavior ◽  
Finite Number ◽  
Domain Of Attraction ◽  
Distribution Functions ◽  
Complete Theory ◽  
General Distribution ◽  
Stable Law ◽  
Biological Phenomena ◽  
Pareto’S Law

The problem of estimating the exponent of a stable law is receiving an increasing amount of attention because Pareto's law (or Zipf's law) describes many biological phenomena very well (see e.g. Hill (1974)). This problem was first solved by Hill (1975), who proposed an estimate, and the convergence of that estimate to some positive and finite number was shown to be a characteristic of distribution functions belonging to the Fréchet domain of attraction (Mason (1982)). As a contribution to a complete theory of inference for the upper tail of a general distribution function, we give the asymptotic behavior (weak and strong) of Hill's estimate when the associated distribution function belongs to the Gumbel domain of attraction. Examples, applications and simulations are given.

UV solar irradiance from broadband radiation and other meteorological data

2010 ◽  
Vol 96 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Marius Paulescu ◽  
Nicoleta Stefu ◽  
Eugenia Tulcan-Paulescu ◽  
Delia Calinoiu ◽  
Adrian Neculae ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Meteorological Data ◽  
Broadband Radiation

Solar Chimney Power Plant Performance for Different Seasons Under Varying Solar Irradiance and Temperature Distribution

2020 ◽  
Vol 143 (6) ◽  
Author(s):  
Ulku Ece Ayli ◽  
Ekin Özgirgin ◽  
Maısarh Tareq
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Ambient Temperature ◽  
Solar Irradiance ◽  
Power Plants ◽  
Low Cost ◽  
Renewable Energy Sources ◽  
Three Dimensional ◽  
Plant Performance ◽  
Solar Chimney

Abstract One of the most promising renewable energy sources is solar energy due to low cost and low harmful emissions, and from the 1980s, one of the most beneficial applications of solar energy is the utilization of solar chimney power plants (SCPP). Recently, with the advancement in computer technology, the use of computational fluid dynamics (CFD) methodology for studying SCPP has become an extensive, robust, and powerful technique. In light of the above, in this study, numerical simulations of an SCPP through three-dimensional axisymmetric modeling is performed. A numerical model is created using CFD software, and the results are verified with an experimental study from the literature. The amount of solar radiation and surrounding weather (ambient temperature) were analyzed, and the effects of the irradiance and air temperature on the output power of the SCPP were studied. Ambient temperature is considered as one of the most important factors that influence collector efficiency in a negative or a positive manner. Solar irradiance is considered to be the most important factor that has an impact on SCPP performance. The investigation includes the study of the relationship between solar insolation and ambient temperatures during the daytime since the difference between the minimum and maximum power values and the performance are very important considering seasonal changes. According to the results, power values are dependent on the amount of solar radiation as well as the ambient temperature, and the importance of selection of location thus climate for an SCPP is found to affect the design of the SCPP.

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