Quoted from:[1]Characteristic distribution of global solar radiation for Amman, Jordan[J]. Solar & Wind Technology, 1990, 7(2-3):261-266.
https://www.sci-hub.ren/10.1016/0741-983x(90)90095-j
ABSTRACT
Hourly global solar radiation data measured on a horizontal surface in Amman, Jordan, available for the period 1983-1987, have been studied and analysed. Average values of daily, monthly and yearly global radiation, as well as maximum and minimum radiation values, were determined. The average monthly mean daily global radiation ranged from 8.001 to 2.653 kWh m -2 per day. Over the 1983-1987 period, the annual daily mean of global radiation was 5.302 kWh m -2 per day. The maximum monthly mean daily global radiation varied between 8.295 and 3.611 kWh m -2per day whereas that of the minimum monthly mean daily radiation varied between 7.590 and 1.680 kWh m -2 per day. The calculated monthly mean daily global solar radiation data were employed to develop linear correlations between the sunshine hours and each of the average, maximum and minimum global radiation for Amman, using regression technique. The accuracy of the derived correlations was tested using measured radiation data for Amman. The results show that the developed correlations are adequate to predict monthly mean daily global radiation Within a maximum error ranging between 6.6 and 9.6%. The average error incurred in predicting global radiation does not exceed 0.3%.
INTRODUCTION
The objective of the present work is the determination of the solar radiation characteristics for the city of Amman by using actual measurements of the global solar radiation. To achieve this goal the hourly measured solar radiation data available for the 1983 1987 period were used to calculate the average values, as well as the maximum and minimum values of daily, monthly and yearly global radiation. The calculated monthly mean daily values of global radiation and the measured hours of daily bright sunshine for Amman were used to derive linear regression correlations for estimating average, maximum and minimum monthly mean daily global radiation.
Alsaad suggested the following relation to estimate the global radiation for Amman, Jordan:
\( 𝐻/𝐻0 = 0.174 + 0.615 𝑆/𝑆0 . \)
CONCLUSIONS
The results of the present work indicate that Amman has high values of global solar radiation during most months of the year. The average, maximum and minimum solar radiation data obtained can be used for the design and performance evaluation of solar energy devices in Jordan. Three regression correlations were developed to predict the average, maximum and minimum global radiation from the knowledge of the recorded sunshine hours. The accuracy of the obtained correlations was tested using measured solar radiation data. It was found that the average error incurred in predicting global radiation ranged from 0.1 to 0.3% which indicate excellent agreement between predicated and measured values. Each of the maximum and minimum monthly mean daily radiation was related to the average global radiation through linear equation. Such equations permit direct estimation of the maximum and minimum global radiation from the knowledge of average radiation.