Experimental and theoretical investigation of diffuse solar radiation: Data and models quality tested for Egyptian sites

Energy ◽  
2007 ◽  
Vol 32 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Hamdy K. Elminir
Keyword(s):  
Solar Radiation ◽  
Theoretical Investigation ◽  
Diffuse Solar Radiation ◽  
Radiation Data

scholarly journals Comparative Analysis of All-Sky Luminous Efficacy Models Based on Calculated and Measured Solar Radiation Data of Four Worldwide Cities

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Donghyun Seo
Keyword(s):  
Solar Radiation ◽  
Luminous Efficacy ◽  
Local Climate ◽  
Data Resource ◽  
Diffuse Solar Radiation ◽  
Radiation Data ◽  
Data Prediction ◽  
Mandatory Requirement ◽  
Solar Radiation Model

Luminous efficacy model uses solar radiation data to generate illuminance data, and its performance also depends on the quality of solar radiation data. Various luminous efficacy models are reviewed and evaluated to select a universal luminous efficacy model. Since most luminous efficacy models are fitted with specific local climate characteristics, the model that has the least locality as well as accuracy is a mandatory requirement. Three representative luminous efficacy models are selected and evaluated with measured solar radiation and illuminance data from four worldwide cities. It was found that all the evaluated models provide good predictions (over 0.96 R2 value) for both global and diffuse illuminance. Among them, the Perez luminous efficacy model shows the highest performance in terms of accuracy and bias. However, illuminance data prediction based on estimated solar radiation data is more common practice rather than those from measured solar data. The performance of the selected luminous efficacy models is evaluated when recently proposed universal solar radiation model supplies predicted solar radiation data. The result indicates that the quality of estimated solar radiation data has a much deeper impact on the performance of the luminous efficacy model. Within the current limited technology and measured data resource, the consecutive processing of the modified Zhang and Huang solar model and Perez luminous efficacy model could provide the best option to predict both global and diffuse solar radiation and illuminance. But, users of the model-based illuminance data should interpret their simulation results with the error (30%~40% in RMSE and ±6% in MBE) in predicting global and diffuse illuminance.

scholarly journals An Algorithm to Determine the Optimum Tilt Angle of a Solar Panel from Global Horizontal Solar Radiation

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Emanuele Calabrò
Keyword(s):  
Solar Radiation ◽  
Tilt Angle ◽  
Correlation Coefficients ◽  
Solar Panel ◽  
Solar Irradiation ◽  
Theoretical Expression ◽  
Solar Panels ◽  
Mean Values ◽  
Diffuse Solar Radiation ◽  
Radiation Data

This paper proposes an algorithm to calculate the optimum tilt angle of solar panels by means of global horizontal solar radiation data, provided from Earth-based meteorological stations. This mathematical modeling is based on the maximization of the theoretical expression of the global solar irradiation impinging on an inclined surface, with respect to the slope and orientation of the panel and to the solar hour angle. A set of transcendent equations resulted, whose solutions give the optimum tilt and orientation of a solar panel. A simulation was carried out using global horizontal solar radiation data from the European Solar Radiation Atlas and some empirical models of diffuse solar radiation. The optimum tilt angle resulted was related to latitude by a linear regression with significant correlation coefficients. The standard error of the mean values resulted increased significantly with latitude, suggesting that unreliable values can be provided at high latitudes.

A preliminary study of global and diffuse solar radiation data from a SONDA station located in São Martinho da Serra, RS - Brazil (29.44ºS, 53.82ºW)

2005 ◽  
Author(s):  
Ricardo André Guarnieri ◽  
Leonardo Biazi ◽  
Nelson Jorge Schuch ◽  
Sylvio Luiz Mantelli Neto ◽  
Enio Bueno Pereira
Keyword(s):  
Solar Radiation ◽  
Diffuse Solar Radiation ◽  
Radiation Data ◽  
Preliminary Study

A preliminary study of global and diffuse solar radiation data from a SONDA station located in São Martinho da Serra, RS - Brazil (29.44ºS, 53.82ºW)

2005 ◽  
Author(s):  
Ricardo André Guarnieri* ◽  
Leonardo Biazi ◽  
Nelson Jorge Schuch ◽  
Sylvio Luiz Mantelli Neto ◽  
Enio Bueno Pereira
Keyword(s):  
Solar Radiation ◽  
Diffuse Solar Radiation ◽  
Radiation Data ◽  
Preliminary Study

scholarly journals Estimation of Diffuse Solar Radiation for Selected Cities in Nigeria

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
M. S. Okundamiya ◽  
A. N. Nzeako
Keyword(s):  
Solar Radiation ◽  
Global Solar Radiation ◽  
Data Generation ◽  
Multivariable Model ◽  
Data Set ◽  
Diffuse Solar Radiation ◽  
Benin City ◽  
Radiation Data ◽  
Daily Data ◽  
Proposed Model

This study proposes a multivariable model of monthly mean daily diffuse solar radiation on horizontal surfaces for three cities (Abuja, Benin City and Katsina), in Nigeria. The estimation was based on a correlation between clearance index and diffuse to global solar radiation ratio and was computed using monthly mean daily data set for global solar radiation on horizontal surfaces. The predictive efficiency of the proposed model was compared with the observed values and those believed to be universally applicable. The results suggest that the existing methods could be replaced by the developed model for a diffuse solar radiation data generation scheme.

scholarly journals Proposal to Refine Solar Radiation of Typical Meteorological Year Database and Evaluation on the Influence of Air-Conditioning Load

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 524
Author(s):  
Jihui Yuan ◽  
Kazuo Emura ◽  
Craig Farnham
Keyword(s):  
Solar Radiation ◽  
Air Conditioning ◽  
Energy Savings ◽  
Energy Resource ◽  
Global Solar Radiation ◽  
Resource Assessment ◽  
Weather Data ◽  
Diffuse Solar Radiation ◽  
Chinese Standard ◽  
The Impact

The Typical meteorological year (TMY) database is often used to calculate air-conditioning loads, and it directly affects the building energy savings design. Among four kinds of TMY databases in China—including Chinese Typical Year Weather (CTYW), International Weather for Energy Calculations (IWEC), Solar Wind Energy Resource Assessment (SWERA) and Chinese Standard Weather Data (CSWD)—only CSWD is measures solar radiation, and it is most used in China. However, the solar radiation of CSWD is a measured daily value, and its hourly value is separated by models. It is found that the cloud ratio (diffuse solar radiation divided by global solar radiation) of CSWD is not realistic in months of May, June and July while compared to the other sets of TMY databases. In order to obtain a more accurate cloud ratio of CSWD for air-conditioning load calculation, this study aims to propose a method of refining the cloud ratio of CSWD in Shanghai, China, using observed solar radiation and the Perez model which is a separation model of high accuracy. In addition, the impact of cloud ratio on air-conditioning load has also been discussed in this paper. It is shown that the cloud ratio can yield a significant impact on the air conditioning load.

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