This study covers the performance of a photovoltaic power generation project and an economic analysis of the project. SAM simulation tool, developed by NREL, a laboratory under DOE of USA, was used as a universal tool, and Korean weather data, electricity trading system in Korea, and Korean government incentive programs were considered. By doing so, we suggested a methodology that will be able to carry out the analysis of power generation performance and economic efficiency when photovoltaic power generation project is planned in Korea. For example, we presented a case study of a photovoltaic power generator operated in 20 megawatt grade photovoltaic power plant in Incheon, a city in Seoul metropolitan area in Korea. We validated the suggested Korea model methodology of economic analysis of a project by analyzing the performance and economic efficiency of this power generation project. The economic analysis by suggested methodology is considered to have sufficient validity, and is expected to be used in model development of photovoltaic power generation project site selection and methodology development.