Development and evaluation of empirical models for the estimation of hourly horizontal diffuse solar irradiance in the United Kingdom

Solar irradiation data is required in many applications to obtain the solar energy output. However, not always available, especially horizontal surface diffuse irradiation. This has led creation of empirical models predict these values. The aim this paper develop an model for estimation hourly irradiance on surfaces. Initially, a set existing have been evaluated test their accuracy. New developed based ground level measurements global and that obtained from three different regions United Kingdom: South Yorkshire, Norfolk, West Sussex period between 1982 1999. created each region correlate fraction (kd) clearness index (kt), were accuracy using error histograms by contrasting datasets. Finally, comparison new showed correlations significantly improved study.