The concentrating photovoltaic (CPV) systems are a promising technology to obtain clean energy. However, these systems are not equally convenient worldwide due to different climatic conditions. The main aim of this paper is to analyze energy and economic performances of a point-focus CPV system for a residential user when its installation site varies. Three locations, Riyadh, Copenhagen, and Palermo, characterized by very different weather conditions are chosen. A model that links the electrical power of a triple-junction (TJ) cell with its temperature and concentrated radiation incident on it is experimentally developed to evaluate the energy performance of the CPV system. A comparison of the three localities for typical winter and summer sunny days indicates that the higher values of the TJ cell temperature are reached in summer, over 70°C at Riyadh, and its electrical power is reduced compared to a winter day. In winter, a TJ cell in Riyadh supplies an electric power of about 20% higher than that in other two cities, while in summer, the maximum power is observed at Copenhagen. On the contrary, the electrical producibility also depends on the sunlight daily hours number during the year. Hence, considering the real distribution of direct normal irradiance (DNI) and the environmental temperature for each locality, a CPV system composed of modules of 90 cells adopted for a residential user is sized. The electric producibility of the CPV system, by varying its module number, is evaluated for different localities together with the optimal number of the modules which is able to maximize the investment profitability.