Abstract In this paper, the concept design of a small-scale CSP system for residential application is presented and by means of analytical simulations. The concept configuration consists of 48 hexagonal heliostats for a total reflecting surface area of 8.7 m2 and a nominal power of 5 kWth. The main objective of this work is to describe the design of a small-scale CSP system and to present an analytical simulation tool with the aim to assess the influence of different irradiance data on the performance of the system. Three different Italian locations have been considered: the city of Ghedi for the North of Italy, Roma for the Centre and Bari for the South. The simulations using the solar radiation data (SoDa) in 2005 and the mean year data of the Meteonorm database are analyzed and compared. Results disclose that the performance calculated using single year and mean year irradiance data for Roma and Bari differ less than 10%. Instead, in the case of Ghedi the difference is larger than 20%. In addition, the simulation tool allows to evaluate the thermal energy collected throughout the year: in Roma and Bari it is over 7721 kWh and 7647 kWh respectively, which is a consistent amount of energy that can be used for residential and civil applications; in Ghedi, only 5384 kWh are collected.