Evaluation of satellite and meteorology data to estimate solar irradiance over five cities in Malaysia

In this paper, meteorology and satellite data are evaluated to estimate global and direct solar irradiance over Malaysia. The meteorology data consist of direct solar irradiance were for 2013 and the satellite data were global solar irradiance from year 2000 till 2004. The estimated global solar irradiance were then compared with observe satellite data and their performance were judge by using statistical indicators, including root mean squared error and mean percentage error. The 5 cities studied in Malaysia includes Kota Kinabalu (KK), Kuching (KC), Ipoh (IP), Alor Setar (AS) and Kuantan (KU). The yearly average of hourly solar irradiance for all 5 cities throughout a year lies between 193 W/m² and 208 W/m². The highest solar irradiance has been estimated at 216 W/m² in the month of March due to the dry season, and the minimum solar irradiance is predicted in the month of December is 164 W/m² that coincides with the rainy season in Malaysia. Results show that the proposed global and direct solar irradiance models present good regression coefficient (R²) value of 0.9661 and 0.9549 respectively. The average diffuse solar irradiance cast over these cities were 3.0% (correction factor) of global solar irradiance. Since Malaysian government are focusing on renewable and clean energy, these models and analyses will benefit the government and education department for further development in solar technologies.