The heater (Fig. 2) is formed of 20 curved pipes of a 1 cm of internal diameter; each pipe has a length of 0.49 m. They allow increasing the exchange area between the working fluid inside the engine and the heat source. Three thermocouples are placed respectively inside the heater, outside the heat and in heating system. The heat source of the Stirling engine is formed by an electrical resistance surrounding the heater tubes. The system is insulated to minimize thermal losses (Fig. 3). The electrical resistance can be replaced by any source of heat (Fig. 4) (biomass or bio-carburant burner, thermal losses from coal plant, etc.).