The product competitiveness of plug-in hybrid vehicles would increase dramatically if the
driving mileage corresponding solely to the initial battery charge without starting the engine
-Electric Vehicles (EV) driving mileage - increased. On the other hand, in terms of comfort, as the
heating while the engine is off relies on electric water heaters, there are some disadvantages
including increased power consumption as well as decreased EV driving mileage. This paper
introduces the power-saving heat pump system which is used as a heat source for the water heater.
