Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: Hourly Global Solar Radiation Estimates on a Horizontal Plane | Journal of Physical Science Vol. 21 2 51-66 2010 51 Hourly Global Solar Radiation Estimates on a Horizontal Plane Abdul Majeed Muzathik1 Wan Mohd Norsani Wan Nik1 Khalid Samo1 and Mohd. Zamri Ibrahim2 department of Maritime Technology Faculty of Maritime Studies and Marine Science 2Department of Engineering Science Faculty of Science and Technology University Malaysia Terengganu 21030 Kuala Terengganu Malaysia Corresponding author muzathik64@ Abstract The hourly global solar radiation If model strongly depends on the climatic characteristics of a considered site. In this paper six empirical models were used to estimate the If from daily radiation on the eastern coast of Malaysia. The measured If data were obtained from the Malaysian Meteorology Department for the period of2004-2008. In order to determine the performance of the models the statistical parameters normalised mean bias error NMBE normalised root mean square error NRMSE correlation coefficient r and a t-test were used. The If values were calculated by using the selected models. The results were compared with the measured data. This study finds that the Collares-Pereira and Rabl model performed better than the other models. Keywords Collares-Pereira and Rabl model global solar radiation hourly solar radiation If models statistical tests solar energy design Abstrak Pilihan model sinaran solar global perjam If adalah sangat bergantung kepada ciri-ciri iklim lokasi yang ditentukan. Dalam kertas kerja ini enam model empirikal digunakan untuk menganggar If dari sinaran harian di pantai timur Malaysia. If yang diukur diperolehi dari Jabatan Meteorologi Malaysia bagi jangka masa 20042008. Bagi menentukan prestasi model parameter statistik ralat pincang purata ternormal NMBE ralat punca ganda dua ternormal NRMSE pekali korelasi r dan ujian t digunakan. Nilai It dihitung menggunakan model-model tersebut dan keputusan dibandingkan dengan data yang diukur. Kajian ini mendapati bahawa model Collares-Pereira
