Monthly-Specific Daily Global Solar Radiation Estimates Based On Sunshine Hours In Wa Ghana

Abstract Daily mean global solar radiation data are required for solar energy system design evaluation and performance studies is generally not available for a number of sites especially in remote locations. This study evaluates different empirical models based on Angstrom-Prescott model to estimate daily mean global solar radiation using month-specific correlations based on sunshine hours. Hourly solar radiation data measured at Wa Polytechnic weather station from 2010-2012 were used to perform the calculations using selected models. The following models were included Angstrom-Prescott Akinoglu and Ecevit Samuel Newland Ampratwum and Dorvlo KadirBakirchi and Almoroxet.al. Statistical indices show that all models for each month show reasonably good agreement with measured data. The model by Ampratwum and Dorvlo in the form HHoablognNshows very good agreement for most monthly-specific correlations in the year. The models presented can be used to estimate daily and monthly mean global solar radiation in Wa Polytechnic site and in elsewhere with similar climatic conditions where radiation data are unavailable. The present work will help to advance the state of knowledge of global solar radiation to the point where it has applications in the estimation of daily mean global solar radiation.