Energy
F. O. Aweda; T. K. Samson
Abstract
This current study was conducted on rainfall and air temperature data obtained from the archive of the HelioClim website to determine the relationship between the two parameters. The study aimed at the relationship between rainfall and air temperature. The data of thirty-four (34) years spanning from ...
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This current study was conducted on rainfall and air temperature data obtained from the archive of the HelioClim website to determine the relationship between the two parameters. The study aimed at the relationship between rainfall and air temperature. The data of thirty-four (34) years spanning from 1985 to 2019 was analyzed using Mann-Kendal statistics on the trend of the rainfall series while the normality of rainfall series was determined using Kolmogorov- Smirnov test across six southwest stations of Nigeria. The results revealed the highest mean rainfall in Akure (198.9 mm) while the least rainfall in Ado-Ekiti (163.4 mm). The maximum rainfall was in Abeokuta (865.8 mm) with Iwo having the highest disparity in rainfall (SD=148.8 mm) compared with other stations. The skewness in Abeokuta (Skewness = 0.9 mm) was higher compared with Ado-Ekiti, Akure, Ibadan, Ikeja and Iwo with skewness values of 0.7 mm, 0.4 mm, 0.7 mm, 0.6 mm and 0.7 mm, respectively. The maximum air temperature was recorded in Iwo (301.7 K) and the minimum air temperature in Ado-Ekiti (293.3 K). The skewness obtained in Akure (-0.2) and Ikeja (-0.3) was less than zero indicating that air temperature decreased more than it increased in these areas while in other stations, Abeokuta (0.01), Ado-Ekiti (0.22), Ibadan (0.02) and Iwo (0.24), the skewness was greater than zero meaning that air temperature increased more than it decreased in these stations.
F. O. Aweda; S. Adebayo; T. K. Samson; I. A. Ojedokun
Abstract
In this study, the net radiation was estimated using a simple straightforward expression proposed by different researchers, which is based on the principle of the Fourier Series Technique. The estimation of net radiation of Iwo ( ) from the data collected from the archive of HelioClim satellite MERRA- ...
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In this study, the net radiation was estimated using a simple straightforward expression proposed by different researchers, which is based on the principle of the Fourier Series Technique. The estimation of net radiation of Iwo ( ) from the data collected from the archive of HelioClim satellite MERRA- 2 (i.e. global solar radiation and air temperature) was done on the real and imaginary measurements. The result of both real and imaginary radiation at maximum revealed ( ) and minimum at about ( ), while solar radiation and temperature revealed about ( ) and 299K maximum and minimum ( ) and 297.7K, respectively. Statistically, the result indicated that the regression coefficient of 3.959 with t- statistics of 3.34 and p < 0.05 indicates that for every 1K increase in air temperature, solar radiation will increase by 3.959, which shows that both solar radiation and temperature have a significant effect on net radiation. Therefore, the researchers concluded that Iwo had maximum real net radiation in February with months such as January, March, July, August, October and December as minimum radiation while imaginary radiation had its maximum and minimum in September and August respectively.
F. O. Aweda; J. A. Oyewole; J. B. Fashae; T. K. Samson
Abstract
The extraterrestrial radiation is the solar radiation received at the top of the earth’s atmosphere on horizontal surface. This quantity over selected stations in the tropics was investigated. Daily data of the extraterrestrial radiation on the earth horizontal surface for the year 2018 for stations: ...
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The extraterrestrial radiation is the solar radiation received at the top of the earth’s atmosphere on horizontal surface. This quantity over selected stations in the tropics was investigated. Daily data of the extraterrestrial radiation on the earth horizontal surface for the year 2018 for stations: Iwo, Abuja, Enugu, Port-Harcourt, Sokoto and Maiduguri obtained from the archive of HelioClim website were analyzed using MATLAB and Statistical Packages for Social Science (SPSS Version 20.0) to estimate the extraterrestrial radiation of the station considered. The results of the MATLAB revealed that the value of the coincidence is across all stations. In January, the values between 15 - 20 peaks were observed in the year with the Irradiation ( ) and the maximum ( ). The results revealed the Root Mean Square Error RMSE for Sokoto (139.99), Abuja (162.72), Iwo (177.07), Maiduguri (171.34), Enugu (191.07), Port-Harcourt (212.27). The results also revealed that quadratic trend equation which accounted in the range 95.9% - 41.9%. The results then concluded that Sokoto and Maiduguri have the highest solar Irradiance as revealed by the result.
F. O. Aweda; T. K. Samson
Abstract
Solar radiation is an important parameter in the study of electricity and/or thermal system installation. Direct monthly irradiance data measurements of the earth’s horizontal surface irradiance for the year 1985 to 2019 for nine stations (Sokoto, Birnin Kebbi, Maiduguri, Ilorin, Calabar, Port-Harcourt, ...
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Solar radiation is an important parameter in the study of electricity and/or thermal system installation. Direct monthly irradiance data measurements of the earth’s horizontal surface irradiance for the year 1985 to 2019 for nine stations (Sokoto, Birnin Kebbi, Maiduguri, Ilorin, Calabar, Port-Harcourt, Enugu, Iwo, and Ikeja) were collected from the achieve of HelioClim satellite website. The stationarity of the series was determined using the time plot of the irradiance data between the periods under study but the formal test of stationarity was carried out using the Augmented Dickey-Fuller (ADF) test with a p-value less than 0.05 signifying stationarity. Different autoregressive integrated moving average (ARIMA) models were fitted to the irradiance data for each of the selected stations. The results revealed that Sokoto, Maiduguri, and Kebbi have their maximum solar irradiance at about and their minimum at about , while Ilorin has its maximum solar irradiance at about and its minimum solar irradiance at about . Ikeja, Iwo and Port-Harcourt, Calabar and Enugu have their maximum solar irradiance and their minimum solar irradiance at about . It is therefore concluded that for Kebbi, Iwo and Maiduguri, the best model was ARIMA (3,0,3), for Calabar and Sokoto, it was ARIMA (2,0,2) while for other locations like Enugu, Ikeja, Ilorin and Port Harcourt, ARIMA (2,0,3) was the best model for forecasting irradiance in these study areas. The forecasted values of irradiance between January till December 2020 with its corresponding 95% confidence levels indicate good prediction of solar irradiance for future occurrence.
