An Estimation of Solar Radiation using Robust Linear Regression Method

AbstractThe air temperature data is the most important component to estimate the solar radiation in photovoltaic systems. From the Malaysia Meteorological Department, the data of air temperature and solar radiation can be found the hourly, daily, monthly and also the annually. Based on solar radiation data for the past 26 years, the average monthly solar radiation was 5009.56 Wh/m2. It was greater than the normal solar radiation (3 kWh/m2), which indicates that the sky in Perlis was clear and very high solar radiation intensity for the months in the past 26 years. This paper presents an investigation of a relationship between solar radiation and temperature in Perlis, Northern Malaysia for the year of 2006. The Least Trimmed Squares (LTS) robust regression model was selected to estimate the solar radiation since the robust method is do not breakdown easily and are not much influenced by outliers