scholarly journals Evaluation of different sunshine-based models for predicting global solar radiation – case study: New Borg El-Arab city, Egypt

2018 ◽  
Vol 22 (2) ◽  
pp. 979-992 ◽  
Author(s):  
Gasser Hassan ◽  
Elsayed Youssef ◽  
Mohamed Ali ◽  
Zahraa Mohamed ◽  
Ahmed Hanafy

The unavailability of the solar radiation measurements for different locations around the world leads to develop various empirical models to estimate the global solar radiation. In this consider, this study aims to investigate the performance of different solar radiation models to predict the monthly average daily global solar radiation on a horizontal surface. To achieve this, the measured global solar radiation data for a case study location are used. The model predictions are compared with the measured data to introduce the most accurate model for estimating the global solar radiation. The performance of each model is evaluated based on the different statistical indicators. The results show that the Robaa model has the best performance among the other models. Consequently, it can be used for estimating global solar radiation on a horizontal surface in the location under consideration. The accurate estimations of the global solar radiation using this approach can be used in the design and evaluation of performance for different solar applications.

2021 ◽  
Vol 14 (1) ◽  
pp. 35
Author(s):  
Nejib Ghazouani ◽  
Abdulhakim Bawadekji ◽  
Alaa A. El-Bary ◽  
Mahmoud M. Elewa ◽  
Nidhal Becheikh ◽  
...  

Solar radiation is considered the main renewable energy source which reshapes the global sustainability plan for future development. Due to the lack of solar radiation measurements, this work investigates the performance of several temperature-based hybrid solar radiation models combining the parametric, statistical and satellite data approaches to estimate the global solar radiation on a horizontal surface. Over 35 years of meteorological data in the new location, Arar City, KSA (Latitude 30°96′ N and longitude 41°05′ E) are employed to establish and validate the models. These models are validated using two datasets with different averaging time spans to investigate the accuracy and reliability of different models as forecasting tools for the solar radiation. The mostly common statistical indicators are calculated to identify the most accurate model. The results show that Model (1) has the best performance among all models with high reliability as a solar radiation forecasting tool in this new location. This model is also validated against the widely-used datasets, namely NASA, On-Site measurements and PVGIS-SARAH data. The model shows excellent values for statistical indicators with high values of coefficient of determination, R2 > 0.955, presenting the best performance regardless of the time span of the validation datasets.


Author(s):  
Abdulhamid Yusuf ◽  
Hakeem Bolarinwa ◽  
Lukman Animasahun ◽  
Yinusa Babatunde

An analysis of measured global solar radiation (GR) in Osogbo (7.77oN, 4.57oE, 288m) is presented in the form of hourly average, monthly average and percentage frequency distribution. The experimental data corresponds to a year data of 2017. The results reveal that the monthly average values of daily total radiation exhibit seasonal variation with maximum value in dry season month of March (16.59MJ/m2) and minimum value in wet season month of August (8.98 MJ/m2). The annual average GR value is 14.20 MJ/m2 while the annual cumulative GR is 5122 MJ/m2. The solar radiation climate of Osogbo has also been compared to those reported for a number of locations. The percentage frequency of days possessing irradiation rate greater than 15 MJ/m2 is 14 percent whereas that possessing less than 10 MJ/m2 is 61 percent. We conclude, based upon the above analysis that Osogbo is characterized by relatively low global solar radiation.


2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Mohammed Benchrifa ◽  
Hajar Essalhi ◽  
Rachid Tadili ◽  
Mohammed N. Bargach ◽  
Abdellah Mechaqrane

The main objective of this work is to create a daily updated database that includes all components of solar radiation, either energetic or spectral radiation. This will lead us to quantify the Moroccan solar potential and to determine the dimensions of all types of solar thermal and photovoltaic systems. Consequently, the obtained database will be the fundamental support for engineers, designers, and all organizations interested in developing solar systems, in different regions throughout Morocco. It will also be a basic tool for researchers in modelling and simulating the new solar systems. Firstly, we used one year’s worth of measurements of the different components of the solar radiation, provided by the National Meteorological Department, to establish the extrapolation equations between the global radiation at the reference site and the global radiation of twenty-eight other sites. As well as with the same measurements, we developed the correlation equations between the global solar radiation and the other solar radiation components. Secondly, from ten years of Fez station’s daily global radiation measurements and through the extrapolation equations, we were able to estimate the global radiation of all Moroccan cities. Then, by using the obtained global radiation data and the correlation equations, we predicted the other components of solar radiation. Subsequently, with a new measurement campaign carried out on several sites, we validated the estimation models by using the usual statistical indicators. In addition, we compared our results with those obtained by other estimation models. The resulting differences for each solar component display the advantage of our model with errors under 6%. To facilitate the use of our results, we compiled them into maps representing the spread of solar radiation across Morocco.


Author(s):  
Zahraa E. Mohamed

AbstractThe main objective of this paper is to employ the artificial neural network (ANN) models for validating and predicting global solar radiation (GSR) on a horizontal surface of three Egyptian cities. The feedforward backpropagation ANNs are utilized based on two algorithms which are the basic backpropagation (Bp) and the Bp with momentum and learning rate coefficients respectively. The statistical indicators are used to investigate the performance of ANN models. According to these indicators, the results of the second algorithm are better than the other. Also, model (6) in this method has the lowest RMSE values for all cities in this study. The study indicated that the second method is the most suitable for predicting GSR on a horizontal surface of all cities in this work. Moreover, ANN-based model is an efficient method which has higher precision.


MAUSAM ◽  
2021 ◽  
Vol 44 (1) ◽  
pp. 39-44
Author(s):  
A. I. SALEM ◽  
M. GABR ◽  
S. SALEEM ◽  
A. H. BASSYOUNI

Daily global solar. radiation data of EI-Kharga for five year (1984-88) have been processed, analysed and classified into eight radiation levels spaced at an interval of 4.19 MJ m-2 day-l. Mean annual monthly and daily total the diurnal variation, and the frequency distribution of daily totals of global solar radiation are computed and discussed. A correlation between the hourly values of the clearness and diffuse indices were obtained and the recommended correlation ,equations were also given. The, results presented in this analysis are encouraging since they Indicate that periods of several days of low radiation of less than 8.38 MJm , day are rare. This In turn means that the weather sequence variations are not expected, to be of great Importance when considering the storage problems Involved In solar process design.


2021 ◽  
Vol 11 (1) ◽  
pp. 71-81
Author(s):  
Moafaq K.S. Al-Ghezi ◽  
Bashar K. Mahmoud ◽  
Tamadher M.A Alnasser ◽  
Miqdam Tariq Chaichan

. In this study, data of the monthly average of daily global solar radiation falling on a horizontal surface, relative humidity, maximum temperature, and duration of sunshine for the city of Baghdad were collected through two sources. First, from the Iraqi Meteorological Authority (IMA) for a period extending from 1961 to 2016. The second is from NASA, for the period from 1984 to 2004. Then, four linear regression models, two single and two polynomials were formulated to calculate the values of the monthly average of daily global horizontal solar radiation (GHSR) incidents. The models calculated the monthly average of daily extraterrestrial radiation and day length, using some data provided by NASA and the IMA. To ensure the validity of the used models, a statistical test was performed for the performance of the proposed models, using the indicators mean bias Error (MBE), root mean square error (RMSE) as well as mean percentage error (MPE). The validation shows the relationship between the measured and computed values (through the analysis of the results), where a great convergence was found between the measured and calculated values. This means that the proposed models can be adapted to predict global solar radiation. The highest values of measured solar radiation were during the month of June, which were 28.555 and 27.280 MJ/m2/day from the IMA and NASA, respectively. The same applies to the radiation calculated using the four empirical models. The month of June was the highest in terms of solar radiation values. The radiation values were 28.947, 26.315, 29.699, and 26.716 MJ/m2/day for the first, second, third, and fourth models, respectively. The lowest values of measured and calculated radiation were during the month of December. Always, radiation measured by the IMA was greater than those of NASA, as well as the values of radiation calculated in the two IMA-based models were greater than the other two NSA-based models. In the absence of a method for measuring the diffuse and direct (beam) solar radiations, as well as the lack of such values by meteorological authorities, and its paramount importance, they were reported to mathematically calculate them in this study. The values of statistical indicators RMSE; MJ/m2/day, MBE; MJ/m2/day and MPE% were (0.4769, 0.0164, 0.2207), (0.8641, 0.1773, -0.9680), (0.6420, 0.3996, -1.1487), (0.9604, 0.218, -1.0225) for the first, second, third and fourth models, respectively. According to the results of the statistical test, it can be indicated that the single linear regression model, based on the IMA’s data (model No.1), is the most accurate to calculate global solar radiation for Baghdad City.


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