1 Application of one-axis sun tracking system Colak I. and Demirtas M. GEMEC-Gazi Electrical Machine and Energy Control Group (Gazi Elektrik Makineleri ve Enerji Kontrol Grubu) Gazi Üniversitesi, Teknik Eğitim Fakültesi, Elektrik Eğitimi Bölümü 06500 Beşevler, ANKARA Abstract This paper introduces design and application of a novel one-axis sun tracking system which follows the position of the sun and allows investigating effects of one-axis tracking system on the solar energy. The tracking system includes a serial communication interface based on RS 485 to monitor whole processes on a computer screen and to plot data as graphic. In addition, system parameters such as the current, the voltage and the panel position have been observed by means of a microcontroller. The energy collected is measured and compared with a fixed solar system for the same solar panel. The results show that the solar energy collected on the tracking system is considerably much efficient than the fixed system. The system developed in this study provides easy installation, simple mechanism and low cost tracking system. 1. INTRODUCTION A block diagram of the grid connected solar system is given in Fig. 1 that includes photovoltaic modules, an inverter, a converter, batteries, a battery charger and DC-AC loads.