International Journal of Engineering and Technology

This work aims at analysing the ground measurement of global horizontal radiation for the city of Vellore, India. This will help in forecasting the value of horizontal radiation, which will be necessary for effective design of the solar systems for thermal and photo-voltaic applications. For this purpose, a mathematical model has been developed using latitude of the location and the relative humidity at that location, as the input parameters. The meteorological data for the period 2000-2014 are collected. Using the measured values of global horizontal radiation and extra-terrestrial horizontal radiation for a given day, the theoretical clearness index, K (without the influence of atmospheric parameters), is determined. Using the theoretical values of K, a model is developed to calculate the horizontal global radiation for any given month. The model is also validated by calculating the theoretical global insolation in Vellore city, for one year and the error was found to be lie within 10%.