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 theoretically estimate the monthly average daily and hourly solar radiation impinging on an unshaded tilted surface in Dhahran, Saudi Arabia. The surface receiving solar radiation is assumed to be fixed at a tilt angle, β, equal to the latitude of Dhahran, φ and oriented such that it is facing south with zero azimuth angle, γ. The calculation of total radiation on a sloped surface from measurements on a horizontal surface is discussed. Monthly average daily and hourly solar radiation values are then tabulated. The results obtained can be effectively employed in solar process design calculations.