A simulation model of finite differences describing a water heating system using a Hybrid Photovoltaic-Thermal collector manufactured in a copolymer material and running in low flow rate conditions has been developed. It includes the essential thermal transfers. The thermal and electrical performances of this solar system have been studied. The choice of the material and the structure of the solar collector are described. The temperatures evolution is modeled in various parts of the solar system and the stratification of the tank is shown. Average electrical, thermal and global efficiencies are calculated each month. We note the importance of thermal recuperation which can catalyze the development of such systems. The utilization of a copolymer for the total design of the solar collector has numerous advantages as reducing the weight, facilitating the manufacturing and reducing the cost. (C) 2009 Elsevier Ltd. All rights reserved.