scholarly journals Empirical models for estimation of global solar radiation using the monthly average daily sunshine hours data for Makurdi, Benue State

2020 ◽  
Vol 12 (1) ◽  
pp. 32-39
Author(s):  
R.S. Sa’id ◽  
S.I. Akor ◽  
U.M. Gana
Keyword(s):  
Solar Radiation ◽  
Diffuse Radiation ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Empirical Models ◽  
Coefficient Of Determination ◽  
Linear Quadratic ◽  
Diffuse Fraction ◽  
Correlation Models ◽  
Sunshine Hours

This paper proposes empirical correlation models for estimating global solar radiation using data of sunshine hours for the location of Makurdi in Benue State of Nigeria. The paper suggests extrapolation of the empirical models for other locations with similar climatic conditions. The proposed models are: Linear, Quadratic, Cubic, Exponential, Power and Logarithmic models. Each of the models is based on Angstrom-Prescott equations for estimating global solar radiation. Any of the models can ease the use of sophisticated equipments, which are expensive, delicate and sometimes develop faults during measurement. The results of the models show that the cubic model is the best with slightly higher coefficient of  determination. The coefficient of  determination of each of the models was found to be 0.952, 0.965, 0.967, 0.965, 0.948& 0.924 respectively, while the absolute correlation was found to be unity. Errors evaluated include MBE, RMSE and MPE with minimal values. The percentage diffuse and direct solar radiations, clearness index and the diffuse fraction were also estimated using the models. The results of the estimations done using the proposed models indicate that there is an estimated average annual global solar radiation of 6056MJm-2, monthly value of 505MJm-2 and daily insolation of 16.82MJm-2 sufficient enough for maximum solar radiation exploitation. Keywords: Solar Radiation, Empirical Models, Diffuse Radiation, Direct Radiation

scholarly journals Estimation of Monthly Average Daily Diffuse Solar Radiation using Empirical Models For Kathmandu Nepal

2019 ◽  
Vol 5 (1) ◽  
pp. 6-13
Author(s):  
B. Pandey ◽  
R. P. Aryal ◽  
C. L. Gnawali ◽  
K. N. Poudyal ◽  
I. B. Karki ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Diffuse Radiation ◽  
Empirical Models ◽  
Linear Quadratic ◽  
Statistical Parameters ◽  
Diffuse Fraction ◽  
Diffuse Solar Radiation ◽  
Monthly Average ◽  
Cubic Model ◽  
Langley Research Center

An accurate knowledge and data of solar radiation and its component are indispensable for the utilization of solar energy. However radiation data are often inaccessible. In this regard, the empirical models are reliable tools. This paper aims to develop and evaluate three simple empirical models (linear, quadratic, and cubic) for estimation of monthly average daily diffuse solar radiation of Kathmandu. Developed Models correlates diffuse fraction with clearness index are based on the satellite data from the NASA Langley Research Center. The performance of models is found to be statistically significant which has been analyzed in terms of statistical indicators like RMSE, MBE and R2. Among the three models, the cubic model is best fit on the basis of statistical parameters. So that cubic model is recommended for the estimation of monthly average daily diffuse radiation at Kathmandu and similar climatic sites of Nepal.

Selection of an Information Source and Methodology for Calculating Solar Resources of the Kyrgyz Republic

2020 ◽  
pp. 236-272
Author(s):  
Alisher F. Narynbaev ◽  
Baatai M. Maksatov ◽  
Alexey Gennad'evich Vaskov ◽  
Galina V. Deryugina ◽  
Roman V. Pugachev
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Information Source ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Empirical Models ◽  
Kyrgyz Republic ◽  
Detailed Data ◽  
Grid Systems ◽  
Selection Of

Detailed data on incoming solar radiation are needed in the design of solar energy systems of any scale: from large PV plants to small off-grid systems. However, in most cases, obtaining data on measurements of solar radiation is connected with difficulties due to financial or technical restrictions. Often, ground-based measurements of solar radiation are either not carried out at all or only the value of the global horizontal intensity of solar radiation is measured. The aim of the present study is to review and to verify some existing empirical models of the global solar radiation and its components for the climatic conditions of Kyrgyzstan as well as to estimate the applicability of Meteonorm database model for the available solar radiation in the territory of Kyrgyzstan. The necessity to select the most suitable models of the solar radiation is called by the lack of similar studies on this direction for the conditions of the country.

Selection of an Information Source and Methodology for Calculating Solar Resources of the Kyrgyz Republic

2021 ◽  
pp. 578-615
Author(s):  
Alisher F. Narynbaev ◽  
Baatai M. Maksatov ◽  
Alexey Gennad'evich Vaskov ◽  
Galina V. Deryugina ◽  
Roman V. Pugachev
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Information Source ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Empirical Models ◽  
Kyrgyz Republic ◽  
Detailed Data ◽  
Grid Systems ◽  
Selection Of

Detailed data on incoming solar radiation are needed in the design of solar energy systems of any scale: from large PV plants to small off-grid systems. However, in most cases, obtaining data on measurements of solar radiation is connected with difficulties due to financial or technical restrictions. Often, ground-based measurements of solar radiation are either not carried out at all or only the value of the global horizontal intensity of solar radiation is measured. The aim of the present study is to review and to verify some existing empirical models of the global solar radiation and its components for the climatic conditions of Kyrgyzstan as well as to estimate the applicability of Meteonorm database model for the available solar radiation in the territory of Kyrgyzstan. The necessity to select the most suitable models of the solar radiation is called by the lack of similar studies on this direction for the conditions of the country.

Simple Correlation Models for Estimation of Horizontal Global Solar Radiation for Oran, Northwest Algeria

2017 ◽  
Vol 32 ◽  
pp. 124-132 ◽  
Author(s):  
Nouar Aoun ◽  
Kada Bouchouicha
Keyword(s):  
Solar Radiation ◽  
Sunshine Duration ◽  
Global Solar Radiation ◽  
Statistical Testing ◽  
Coefficient Of Determination ◽  
Total Solar Radiation ◽  
Mean Values ◽  
Correlation Models ◽  
Testing Error ◽  
Trigonometric Model

In the literature, several correlation models have been developed to predict solar radiation on horizontal surfaces. In this paper, the daily solar radiation data and sunshine duration data measured during the period of 2006-2010, were used to calculate the monthly mean values of daily total solar radiation using five modified Angstrom–Prescott model and three day of the year based empirical models of Oran city (35°42 N and 00°36 W) in Algeria. Furthermore, those modified models are compared with three existing models. In order to evaluate the accuracy of the models, the statistical testing error such as R2, RMSE, rRMSE, MAPE and MBE are used. According to statistical test results and from the sunshine duration models, the polynomial model (#4) showed the best estimation results with a coefficient of determination R2=0.991, rRMSE=4.129%, and MAPE=3.635%. Furthermore, the accurate model from the day of the year models is the model (7), with R2=0.987, rRMSE=4.067%, and MAPE=3.5194%. Moreover, this paper finds that the best accuracy model to estimate the monthly mean daily solar radiation on horizontal surfaces in Oran city is the sine and cosine wave trigonometric model (#7).

scholarly journals Diffuse solar radiation and associated meteorological parameters in India

1996 ◽  
Vol 14 (10) ◽  
pp. 1051-1059 ◽  
Author(s):  
A. B. Bhattacharya ◽  
S. K. Kar ◽  
R. Bhattacharya
Keyword(s):  
Solar Radiation ◽  
Meteorological Parameters ◽  
Global Radiation ◽  
Low Frequency ◽  
Diffuse Radiation ◽  
Global Solar Radiation ◽  
Surface Radiation ◽  
Diffuse Solar Radiation ◽  
Sunshine Hours ◽  
The Tropics

Abstract. Solar diffuse radiation data including global radiation, shortwave and longwave balances, net radiation and sunshine hours have been extensively analyzed to study the variation of diffuse radiation with turbidity and cloud discharges appearing in the form of atmospherics over the tropics. Results of surface radiation measurements at Calcutta, Poona, Delhi and Madras are presented together with some meteorological parameters. The monthly values of diffuse radiation and the monthly ratios of diffuse to global solar radiation have been examined, with a special emphasis in relation to the noise level of atmospherics at Calcutta in the very low frequency band. The results exhibit some definite seasonal changes which appear to be in close agreement with one another.

scholarly journals Empirical Models for Estimating Tropospheric Radio Refractivity Over Osogbo, Nigeria

2019 ◽  
Vol 13 (1) ◽  
pp. 43-55
Author(s):  
D. O. Akpootu ◽  
A. M. Rabiu
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Global Solar Radiation ◽  
Absolute Temperature ◽  
Empirical Models ◽  
Coefficient Of Determination ◽  
Mean Bias Error ◽  
Percentage Error ◽  
Bias Error ◽  
Monthly Average

Background:Estimation of tropospheric radio refractivity is significant in the planning and design of terrestrial communication links.Methods:In this study, the monthly average daily atmospheric pressure, relative humidity and temperature data obtained from the National Aeronautics and Space Administration (NASA) during the period of twenty two years (July 1983 - June 2005) for Osogbo (Latitude 7.470N, Longitude 4.290E, and 302.0 m above sea level) were used to estimate the monthly tropospheric radio refractivity. The monthly average daily global solar radiation with other meteorological parameters was used to developed one, two, three and four variable correlation(s) tropospheric radio refractivity models for the location. The accuracy of the proposed models are validated using statistical indicator of coefficient of determination (R2), Mean Bias Error (MBE), Root Mean Square Error (RMSE), Mean Percentage Error (MPE), Nash - Sutcliffe Equation (NSE) and Index of Agreement (IA).Results:In each case one empirical model was recommended based on their exceptional performances after ranking, except for the two variation correlations with two empirical models. The recommended models were further subjected to ranking from which the three variable correlations model that relates the radio refractivity with the absolute temperature, relative humidity and global solar radiation was found more suitable for estimating tropospheric radio refractivity for Osogbo with R2= 100.0%, MBE = -0.2913 N-units, RMSE = 0.3869 N-units, MPE = 0.0811%, NSE = 99.9999% and IA = 100.00%.Conclusion:The newly developed recommended models (Equations 16c, 17d, 17f, 18d and 19) can be used for estimating daily and monthly values of tropospheric radio refractivity with higher accuracy and has good compliance to highly varying climatic conditions for Osogbo and regions of similar climatic information.

scholarly journals The diffuse component of the global solar radiation at Qena / Egypt

MAUSAM ◽  
2021 ◽  
Vol 49 (4) ◽  
pp. 469-474
Author(s):  
Dr. SAYED. M. EL. SHAZLY
Keyword(s):  
Solar Radiation ◽  
Regression Models ◽  
Radiation Effect ◽  
Statistical Evaluation ◽  
Diffuse Radiation ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Diffuse Component ◽  
Diffuse Solar Radiation ◽  
Basic Procedure

Diffuse solar radiation on horizontal surfaces is estimated at Qena / Egypt. The basic procedure is to develop relationships of the widespread use Liu & Jordan types between the daily global horizontal radiation (G) and its diffuse component (D) using measured values of these two quantities. An error analysis has been done for the results of diffuse radiation calculated using the regression models obtained in this paper and those estimated from other known ones of the Liu & Jordan type, According to statistical evaluation of the various relationships, it is seen that our models provide the best estimation of the diffuse radiation, Effect of climatic conditions was considered in the discussion.

scholarly journals Empirical Models for Estimating Tropospheric Radio Refractivity Over Osogbo, Nigeria

2019 ◽  
Vol 13 (1) ◽  
pp. 43-55
Author(s):  
D. O. Akpootu ◽  
A. M. Rabiu
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Global Solar Radiation ◽  
Absolute Temperature ◽  
Empirical Models ◽  
Coefficient Of Determination ◽  
Mean Bias Error ◽  
Percentage Error ◽  
Bias Error ◽  
Monthly Average

Background:Estimation of tropospheric radio refractivity is significant in the planning and design of terrestrial communication links.Methods:In this study, the monthly average daily atmospheric pressure, relative humidity and temperature data obtained from the National Aeronautics and Space Administration (NASA) during the period of twenty two years (July 1983 - June 2005) for Osogbo (Latitude 7.470N, Longitude 4.290E, and 302.0 m above sea level) were used to estimate the monthly tropospheric radio refractivity. The monthly average daily global solar radiation with other meteorological parameters was used to developed one, two, three and four variable correlation(s) tropospheric radio refractivity models for the location. The accuracy of the proposed models are validated using statistical indicator of coefficient of determination (R2), Mean Bias Error (MBE), Root Mean Square Error (RMSE), Mean Percentage Error (MPE), Nash - Sutcliffe Equation (NSE) and Index of Agreement (IA).Results:In each case one empirical model was recommended based on their exceptional performances after ranking, except for the two variation correlations with two empirical models. The recommended models were further subjected to ranking from which the three variable correlations model that relates the radio refractivity with the absolute temperature, relative humidity and global solar radiation was found more suitable for estimating tropospheric radio refractivity for Osogbo with R2= 100.0%, MBE = -0.2913 N-units, RMSE = 0.3869 N-units, MPE = 0.0811%, NSE = 99.9999% and IA = 100.00%.Conclusion:The newly developed recommended models (Equations 16c, 17d, 17f, 18d and 19) can be used for estimating daily and monthly values of tropospheric radio refractivity with higher accuracy and has good compliance to highly varying climatic conditions for Osogbo and regions of similar climatic information.

scholarly journals Empirical Models for Estimating Global Solar Radiation over the Ashanti Region of Ghana

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Emmanuel Quansah ◽  
Leonard K. Amekudzi ◽  
Kwasi Preko ◽  
Jeffrey Aryee ◽  
Osei R. Boakye ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Air Temperature ◽  
Empirical Model ◽  
Global Solar Radiation ◽  
Temperature Measurements ◽  
Coefficient Of Determination ◽  
Temperature Dependent ◽  
Tropical Regions ◽  
Ashanti Region ◽  
Sunshine Hours

The performances of both sunshine and air temperature dependent models for the estimation of global solar radiation (GSR) over Ghana and other tropical regions were evaluated and a comparison assessment of the models was carried out using measured GSR at Owabi (6°45′0′′N, 1°43′0′′W) in the Ashanti region of Ghana. Furthermore, an empirical model which also uses sunshine hours and air temperature measurements from the study site and its environs was proposed. The results showed that all the models could predict very well the pattern of the measured monthly daily mean GSR for the entire period of the study. However, most of the selected models overestimated the measured GSR, except in April and November, where the empirical model using air temperature measurements underestimated the measured GSR. Nevertheless, a very good agreement was found between the measured radiations and the proposed models with a coefficient of determination within the range 0.88–0.96. The results revealed that the proposed models using sunshine hours and air temperature had the smallest values of MBE, MPE, and RMSE of −0.0102, 0.0585, and 0.0338 and −0.2973, 1.7075, and 0.9859, respectively.

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