Empirical Modelling and Estimation of Solar Radiation from Tilted Surfaces Relative to Angular Solar Relations

Abstract

Interest in solar energy has prompted the accurate measurement and

mapping of solar energy resources of the globe. Solar radiation data

are available in several forms. Most radiation data available for

horizontal surfaces include both direct and diffuse radiation. This is

normally done by using solar-meters. Most solar-meters

measurements are recorded simply as total energy (global radiation)

incident on the horizontal surface; other measurements separate the

direct (beam) and the scattered (diffuse) radiation. Radiation data

are the best source of information for estimating average incident

radiation and for the proper designing of a solar water heating

system. A precise analysis and design of a solar water heating system

requires knowledge of the solar energy obtained from the sun and

the availability of global solar radiation and its components at the

location of project site. Since the solar radiation reaching the earth’s

surface depends upon climatic conditions of the place, a study of

solar radiation under local climatic conditions is essential. Solar

radiation data were obtained through the use of an empirical model

to predict and estimate solar radiation seems inevitable. The highest

value of solar radiation was obtained in April, 2018 and the average

horizontal radiation on a surface and radiation on a tilted surface

was found to be 966.12W/m2 and 1055.99W/m2

respectively.