scholarly journals Modeling of the hourly horizontal solar diffuse radiation in Sanliurfa, Turkey

2020 ◽  
Vol 24 (2 Part A) ◽  
pp. 939-950
Author(s):  
Nesrin Beyazit ◽  
Fatih Unal ◽  
Husamettin Bulut
Keyword(s):  
Solar Radiation ◽  
Tracking System ◽  
Measurement Data ◽  
Diffuse Radiation ◽  
Measuring Instruments ◽  
Estimation Model ◽  
Diffuse Solar Radiation ◽  
Statistical Errors ◽  
Solar Tracking ◽  
Solar Diffuse Radiation

Horizontal diffuse solar radiation has been calculated over various models by using the total radiation data obtained from the horizontal surface due to reasons such as lack of adequate measurements and expensive measuring instruments. In this study, the measurements were calculated using the obtained data between the years 2009 and 2016 from solar radiation measurement system with solar tracking system, which belongs to the Department of Mechanical Engineering, Sanliurfa Harran University, Turkey. Three horizontal solar diffuse radiation models have been proposed by using the relationship between the diffuse radiation ratio and the clarity index obtained by eight years? data. Horizontal solar diffuse radiation values were calculated and compared with the measurement data for Sanliurfa by using 15 models of diffuse radiation given in the literature and the results obtained from the models. The statistical errors of the proposed models and 15 different diffusive radiation models were calculated. As diffuse radiation varies with time, it is determined that modelling of Model 1 and Model 2 obtained from Sanliurfa data gives better results in terms of clarity index constraints. Furthermore, although the desired success cannot be achieved with Model 2 in terms of tstat, it has been determined that the relevant model provides better results than many models when compared to statistical errors. With the improvements to be made on Model 2, a local estimation model is thought to give better results.

Developing and Evaluation of Various Correlations for Diffuse Solar Radiation for Urla (Izmir, Turkey)

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Orhan Ekren
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Tracking System ◽  
Diffuse Radiation ◽  
Energy System ◽  
Solar Irradiation ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Diffuse Solar Radiation ◽  
Tilted Surface

Characteristics of site-specific solar irradiation is required to optimize a solar energy system. If no tracking system is used, the amount of electricity or heat produced by solar energy depends on the total solar radiation on a tilted surface. Although pyranometer measures direct plus diffuse solar radiation on a horizontal surface, there are many locations where diffuse radiation is not measured. Also, diffuse radiation is necessary to determine the total radiation on a tilted surface. Therefore, in this study, new correlations for diffuse solar radiation is proposed as a function of atmospheric parameters for Urla (Izmir, Turkey). After applying the statistical procedure on the measured data, seven new correlations are proposed for the ratio of hourly average diffuse and total radiation. Also, the ratio of monthly average daily diffuse and total radiation for this region is proposed.

scholarly journals Optimal design of the solar tracking system of parabolic trough concentrating collectors

2020 ◽  
Vol 15 (4) ◽  
pp. 613-619
Author(s):  
Li Kong ◽  
Yunpeng Zhang ◽  
Zhijian Lin ◽  
Zhongzhu Qiu ◽  
Chunying Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Solar Radiation ◽  
Tracking System ◽  
Low Cost ◽  
Parabolic Trough ◽  
The North ◽  
Tracking Mode ◽  
Solar Tracking ◽  
East West

Abstract The present work aimed to select the optimum solar tracking mode for parabolic trough concentrating collectors using numerical simulation. The current work involved: (1) the calculation of daily solar radiation on the Earth’s surface, (2) the comparison of annual direct solar radiation received under different tracking modes and (3) the determination of optimum tilt angle for the north-south tilt tracking mode. It was found that the order of solar radiation received in Shanghai under the available tracking modes was: dual-axis tracking > north-south Earth’s axis tracking > north-south tilt tracking (β = 15°) > north-south tilt tracking (β = 45) > north-south horizontal tracking > east-west horizontal tracking. Single-axis solar tracking modes feature simple structures and low cost. This study also found that the solar radiation received under the north-south tilt tracking mode was higher than that of the north-south Earth’s axis tracking mode in 7 out of 12 months. Therefore, the north-south tilt tracking mode was studied separately to determine the corresponding optimum tilt angles in Haikou, Lhasa, Shanghai, Beijing and Hohhot, respectively, which were shown as follows: 18.81°, 27.29°, 28.67°, 36.21° and 37.97°.

Improved Accuracy Models For Hourly Diffuse Solar Radiation

2005 ◽  
Vol 128 (1) ◽  
pp. 104-117 ◽  
Author(s):  
T. Muneer ◽  
S. Munawwar
Keyword(s):  
Solar Radiation ◽  
Regression Models ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Evaluation Procedure ◽  
Accuracy Score ◽  
Error Statistics ◽  
Diffuse Solar Radiation ◽  
Energy Applications ◽  
Extensive Evaluation

Solar energy applications require readily available, site-oriented, and long-term solar data. However, the frequent unavailability of diffuse irradiation, in contrast to its need, has led to the evolution of various regression models to predict it from the more commonly available data. Estimating the diffuse component from global radiation is one such technique. The present work focuses on improvement in the accuracy of the models for predicting horizontal diffuse irradiation using hourly solar radiation database from nine sites across the globe. The influence of sunshine fraction, cloud cover, and air mass on estimation of diffuse radiation is investigated. Inclusion of these along with hourly clearness index, leads to the development of a series of models for each site. Estimated values of hourly diffuse radiation are compared with measured values in terms of error statistics and indicators like, R2, mean bias deviation, root mean square deviation, skewness, and kurtosis. A new method called “the accuracy score system” is devised to assess the effect on accuracy with subsequent addition of each parameter and increase in complexity of equation. After an extensive evaluation procedure, extricate but adequate models are recommended as optimum for each of the nine sites. These models were found to be site dependent but the model types were fairly consistent for neighboring stations or locations with similar climates. Also, this study reveals a significant improvement from the conventional k-kt regression models to the presently proposed models.

scholarly journals Coupling Diffuse Sky Radiation and Surface Albedo

2005 ◽  
Vol 62 (7) ◽  
pp. 2580-2591 ◽  
Author(s):  
Bernard Pinty ◽  
Alessio Lattanzio ◽  
John V. Martonchik ◽  
Michel M. Verstraete ◽  
Nadine Gobron ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Land Surface ◽  
Surface Albedo ◽  
Climate Models ◽  
Diffuse Radiation ◽  
Atmospheric Model ◽  
Time Of Day ◽  
Mathematical Form ◽  
Diffuse Solar Radiation ◽  
Atmospheric Scattering

Abstract New satellite instruments have been delivering a wealth of information regarding land surface albedo. This basic quantity describes what fraction of solar radiation is reflected from the earth’s surface. However, its concept and measurements have some ambiguity resulting from its dependence on the incidence angles of both the direct and diffuse solar radiation. At any time of day, a surface receives direct radiation in the direction of the sun, and diffuse radiation from the various other directions in which it may have been scattered by air molecules, aerosols, and cloud droplets. This contribution proposes a complete description of the distribution of incident radiation with angles, and the implications in terms of surface albedo are given in a mathematical form, which is suitable for climate models that require evaluating surface albedo many times. The different definitions of observed albedos are explained in terms of the coupling between surface and atmospheric scattering properties. The analytical development in this paper relates the various quantities that are retrieved from orbiting platforms to what is needed by an atmospheric model. It provides a physically simple and practical approach to evaluation of land surface albedo values at any condition of sun illumination irrespective of the current range of surface anisotropic conditions and atmospheric aerosol load. The numerical differences between the various definitions of albedo for a set of typical atmospheric and surface scattering conditions are illustrated through numerical computation.

scholarly journals Surface global and diffuse solar radiation over China acquired from geostationary Multi-functional Transport Satellite data

2019 ◽  
Author(s):  
Hou Jiang ◽  
Ning Lu ◽  
Jun Qin ◽  
Ling Yao
Keyword(s):  
Solar Radiation ◽  
Satellite Data ◽  
Power Plants ◽  
Numerical Models ◽  
Regional Climate ◽  
Diffuse Radiation ◽  
Terrestrial Ecosystems ◽  
Global Solar Radiation ◽  
Surface Solar Radiation ◽  
Diffuse Solar Radiation

Abstract. Surface solar radiation drives the water cycle and energy exchange on the earth's surface, being an indispensable parameter for many numerical models to estimate soil moisture, evapotranspiration and plant photosynthesis, and its diffuse component can promote carbon uptake in ecosystems as a result of improvements of plant productivity by enhancing canopy light use efficiency. To reproduce the spatial distribution and spatiotemporal variations of solar radiation over China, we generate the high-accuracy radiation datasets, including global solar radiation (GSR) and the diffuse radiation (DIF) with spatial resolution of 1/20 degree, based on the observations from the China Meteorology Administration (CMA) and Multi-functional Transport Satellite (MTSAT) satellite data, after tackling the integration of spatial pattern and the simulation of complex radiation transfer that the existing algorithms puzzle about by means of the combination of convolutional neural network (CNN) and multi-layer perceptron (MLP). All data cover a period from 2007 to 2018 in hourly, daily total and monthly total scales. The validation in 2008 shows that the root mean square error (RMSE) between our datasets and in-situ measurements approximates 73.79 W/m2 (0.27 MJ/m2) and 58.22 W/m2 (0.21 MJ/m2) for GSR and DIF, respectively. Besides, the spatially continuous hourly estimates properly reflect the regional differences and restore the diurnal cycles of solar radiation in fine scales. Such accurate knowledge is useful for the prediction of agricultural yield, carbon dynamics of terrestrial ecosystems, research on regional climate changes, and site selection of solar power plants etc. The datasets are freely available from Pangaea at https://doi.org/10.1594/PANGAEA.904136 (Jiang and Lu, 2019).

Output Power Enhancement of Solar PV Panel Using Solar Tracking System

2019 ◽  
Vol 12 (1) ◽  
pp. 45-49
Author(s):  
Abhishek Kumar Tripathi ◽  
Mangalpady Aruna ◽  
Ch. S.N. Murthy
Keyword(s):  
Solar Radiation ◽  
Output Power ◽  
Tracking System ◽  
The Sun ◽  
Solar Pv ◽  
Design Development ◽  
Pv Panel ◽  
Solar Tracking ◽  
Power Enhancement ◽  
Panel Surface

Solar Photovoltaic (PV) energy conversion has gained much attention nowadays. The output power of PV panel depends on the condition under which the panel is working, such as solar radiation, ambient temperature, dust, wind speed and humidity. The amount of falling sunlight on the panel surface (i.e., solar radiation) directly affects its output power. In order to maximize the amount of falling sunlight on the panel surface, a solar tracking PV panel system is introduced. This paper describes the design, development and fabrication of the solar PV panel tracking system. The designed solar tracking system is able to track the position of the sun throughout the day, which allows more sunlight falling on the panel surface. The experimental results show that there was an enhancement of up to a 64.72% in the output power of the PV panel with reference to the fixed orientation PV panel. Further, this study also demonstrates that the full load torque of the tracking system would be much higher than the obtained torque, which is required to track the position of the sun. This propounds, that the proposed tracking system can also be used for a higher capacity PV power generation system.

Horizontal Tubular Microalgae Photobioreactor Plant View Factors and Diffuse Radiation

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
T. Maor ◽  
J. Appelbaum
Keyword(s):  
Solar Radiation ◽  
Present Article ◽  
Diffuse Radiation ◽  
Design Parameters ◽  
View Factor ◽  
Diffuse Solar Radiation ◽  
Horizontal Tubes ◽  
Vertical Walls ◽  
View Factors

Different view factors and different components of the diffuse solar radiation impinging on a photobioreactor plant for cultivating microalgae products are formulated and calculated in the present article. The outdoor plant consists of multiple horizontal tubes arranged in multiple vertical walls. The diffuse radiation on a tube may come from three directions of the sky: from the aperture between the walls (from the sky above), from the penetration of the diffuse radiation between the tubes, and from the plant edges. Each component of the diffuse radiation is associated with a different view factor. For design parameters of a practical plant, the largest component of the diffuse radiation comes from the sky above the plant.

scholarly journals Monthly average daily diffuse solar radiation in Poland within the period 2005–2015

2018 ◽  
Vol 23 ◽  
pp. 00020
Author(s):  
Małgorzata Kleniewska ◽  
Dorota Mitrowska ◽  
Bogdan H. Chojnicki
Keyword(s):  
Solar Radiation ◽  
Linear Relationship ◽  
Global Radiation ◽  
Diffuse Radiation ◽  
Diffuse Fraction ◽  
Diffuse Solar Radiation ◽  
Monthly Average

In this paper an 11-year series of daily values of diffuse solar radiation registered at 8 actinometric stations in Poland was used to describe the characteristics of diffuse radiation and diffuse fraction of global radiation for the area of Poland. Based on the monthly average daily diffuse, global and extraterrestrial solar radiation a linear relationship between these elements was determined. The obtained equation enables the calculation of the monthly average daily diffuse solar radiation for Poland and the application of its values to further climatology studies.

scholarly journals Simulation of solar radiation during a total solar eclipse: a challenge for radiative transfer

2007 ◽  
Vol 7 (1) ◽  
pp. 499-535
Author(s):  
C. Emde ◽  
B. Mayer
Keyword(s):  
Solar Radiation ◽  
Radiative Transfer ◽  
Solar Eclipse ◽  
Monte Carlo Model ◽  
Three Dimensional ◽  
Diffuse Radiation ◽  
Radiative Transfer Model ◽  
Natural Phenomenon ◽  
Transfer Model ◽  
Diffuse Solar Radiation

Abstract. A solar eclipse is a rare but spectacular natural phenomenon and furthermore it is a challenge for radiative transfer modeling. Whereas a simple one-dimensional radiative transfer model with reduced solar irradiance at the top of the atmosphere can be used to calculate the brightness during partial eclipses a much more sophisticated model is required to calculate the brightness (i.e. the diffuse radiation) during the total eclipse. The reason is that radiation reaching a detector in the shadow gets there exclusively by horizontal (three-dimensional) transport of photons in a spherical shell atmosphere. In this study the first accurate simulations are presented examplified by the solar eclipse at 29 March 2006. Using a backward Monte Carlo model we calculated the diffuse radiation in the umbra and simulated the changing colors of the sky. Radiance and irradiance are decreased by 3 to 4 orders of magnitude, depending on wavelength. We found that aerosol has a comparatively small impact on the radiation in the umbra. We also estimated the contribution of the solar corona to the radiation under the umbra and found that it is negligible compared to the diffuse solar radiation in most parts of the spectrum. Spectrally resolved measurements in the umbra are not yet available. They are challenging due to the low intensity and therefore need careful planning. The new model may be used to support measurements during future solar eclipses.

scholarly journals Modeling the Incident Solar Radiation of the City of N’Djamena (Chad) by the Capderou Method

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Mahamat Hassane Babikir ◽  
Donatien Njomo ◽  
Mahamat Barka ◽  
Mahamoud Youssouf Khayal ◽  
Deli Goron ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Diffuse Radiation ◽  
Theoretical Models ◽  
African Countries ◽  
Incident Solar Radiation ◽  
Diffuse Solar Radiation ◽  
Different Seasons ◽  
The Moment ◽  
Desert Climate

Chad is like many African countries with no meteorological station at the moment to measure solar radiation throughout the country. Thus, theoretical models are used to estimate incident solar radiation. These models are established in correlation form. Our objective was to present a model, which allows the determination of the solar component on two surfaces (horizontal and inclined). This model allowed us to determine, over time, the component of global, direct, and diffuse solar radiation over a period that will cover the different seasons of the year. The calculation is done according to Klein’s days over all the months of the year. The hourly results of the global, direct, and diffuse radiation obtained for all the planes going from January to December are satisfactory compared to the results of the other authors quoted in the literature, which give the maximum and minimum values very close to theirs. These results allowed us to validate the applicability of this model in a climate other than the desert climate.

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