Abstract—Thilawa Special Economic Zone (SEZ) is located beside the Thanlyin and Kyauktan townships, about 20 km southeast side of Yangon City. To meet increasing of power demand in Thilawa SEZ, 50MW dual fuel generators are already constructed in there. Because of the insufficient enough of supply gas, gas turbine generator (GT) are not operated in full efficiency. Due to the fact of future load growth and present gas turbine condition, mega solar power generation system should be considered to construct in Thilawa SEZ area. In this paper, the simulation results of the proposed model have been studied on the basis of cost of energy, pay-back period, environmental emissions etc. and compared three types of system such as PV stand-alone system, Hybrid system (PV and Gas Turbine) and Gas turbine generator system. Performance of each component (i.e. battery, inverter, rectifier etc.) of the model is evaluated and finally sensitivity analysis is performed to optimize the system out of different conditions by using Homer Software. Keywords – Thilawa SEZ, PV System, Homer Software, Optimization and Sensitivity Analysis I. INTRODUCTION In the age of modernization and economic development, energy is the vital ingredient. Its demand is steadily increasing with ever-increasing population along with improvement in living standards. The primary challenge nowadays is to meet this growing energy demand without fully exhausting the resources to be used by future generations. In the last decade, earth’s climate has changed and there have been rigorous debates on global warming by environmentalists and researchers. The major causes being pointed are the growth in world population and rapid industrialization, resulting in increased electricity demand which in turn was met by the conventional electricity sources like coal, oil and gas. Utilization of these conventional electricity sources contributes to the increase in greenhouse gases (GHGs) emissions which brings hazard to our atmosphere. The best solution for this problem is utilization of renewable energy resources. Renewable energy is being seen as an alternative to conventional sources because these are clean and environment friendly, thus may be helpful in mitigating GHG emissions [1]. In the process of Utilization of Renewable energy resources we have to face some challenges like reliability, Ei Mon Zaw is Ph.d thesis student of Department of Electrical Power Engineering, Yangon Technological University, Insein Township, Yangon in Myanmar. (phone: +9595108938; e-mail: ochityar.89@gmail.com ). Aung Ze Ya is Professor at Department of Electrical Power Engineering, Yangon Technological University, Insein Township, Yangon in Myanmar.( e-mail: dr.aungzeya010@gamil.com ). cost, efficiency and Stability. The main drawback of renewable energy resources is they are inconsistency or more fluctuating in nature and depends upon weather atmospheric conditions. In order to provide continue power supply integrate two or more resources and provide storage system. Integrated system of two or more renewable energy systems, also known as Hybrid Renewable Energy System (HRES), is gaining popularity because the sources can complement each other to provide higher quality and more reliable power to customer than single source System. A HRES can be standalone or grid connected. Standalone systems need to have generation and storage capacity large enough to handle the load. In a grid connected system, the size of storage device can be relatively smaller because deficient power can be obtained from the grid. Therefore, the design goals for hybrid power system are the minimization of power production cost, minimization of power purchase from grid (if it is connected to grid), reduction in emission, reduction of the total lifecycle cost and increase in reliability of the power generation of system [2]. Among the all renewable energy resources, solar energy is one of the most popular energy because of its huge potential in nature. Solar energy is a very large, inexhaustible source. The power from the Sun intercepted by the Earth is approximately 2.9 x 10¹³MW, which are many thousands of times larger than the present consumption rate on the earth of all commercial energy sources. Thus in principal, solar energy could supply all the present and future energy needs of the world as a continuous basis. This makes it one of the most promising of the unconventional energy sources Photovoltaic (PV) solar energy conversion is one of the most attractive nonconventional energy sources of proven reliability from micro watts to megawatts. The solar energy can be broadly used in two areas: (1) PV systems which convert solar energy directly into electrical energy and; (2) thermal systems that convert solar energy into thermal energy [3]. In solar PV system, the solar radiation is converted directly into electricity. The most common method of doing this is by the use of silicon solar cells. The power generating unit is the solar module which consists of several solar cells electrically linked together on a base plate. On the whole the major components of a PV system include the arrays which consist of the photovoltaic conversion devices, their interconnections and support, power conditioning equipment that convert the dc to ac and provides regulated outputs of voltage and current; controller, which automatically manages the operation of the total system; as well as the optional storage of battery [4]. Design of Mega Solar Power Generation System in Thilawa Special Economic Zone using Homer Software Ei Mon Zaw #1 , Aung Ze Ya #2 # Department of Electrical Power Engineering, Yangon Technological University 1 ochityar.89@gmail.com 2 dr.aungzeya010@gmail.com