ESTIMATION OF MONTHLY AVERAGE DAILY AND HOURLY SOLAR-RADIATION IMPINGING ON A SLOPED SURFACE USING THE ISOTROPIC SKY MODEL FOR DHAHRAN, SAUDI-ARABIA

In this paper the isotropic sky method of Liu and Jordan is used to th eoretically estimate the monthly average daily and hourly solar radiat ion impinging on an unshaded tilted surface in Dhahran, Saudi Arabia. The surface receiving solar radiation is assumed to be fixed at a tilt angle, beta, equal to the latitude of Dhahran, phi and oriented such that it is facing south with zero azimuth angle, gamma. The calculatio n of total radiation on a sloped surface from measurements on a horizo ntal surface is discussed. Monthly average daily and hourly solar radi ation values are then tabulated. The results obtained can be effective ly employed in solar process design calculations. (C) 1997 Elsevier Sc ience Ltd.