MONTHLY AVERAGE DAILY INSOLATION AND OPTIMUM TILT ANGLE OF SOLAR COLLECTOR IN P.D.R. YEMEN

The knowledge of the available solar irradiation is valuable for the design and assessment of solar energy conversion systems. For P.D.R. Yemen, an accurate prediction of solar irradiation is needed for designing solar systems to be used in the country. In this study an attempt has been made to generate theoretically the daily average insolation on horizontal and tilted surfaces. The optimum tilt angle of the surface is also determined. Different locations covering a wide range of latitude of the country have been studied. A simple mathematical model is used which is mainly based on the latitude, altitude and climatic conditions of the place. A computer program is developed so that the optimum tilt angle of the surface can be determined yearly and at a particular period (seasonally) at different places in the Republic