An integrated energy system consisted of PV panels, EV (electric vehicle), BES (battery energy storage), and a HP (heat pump) coupled with thermal storage tanks (TES) has been studied. The research aimed to minimize the total energy costs by scheduling the optimal power consumption of each device as response to two external signals as part of a demand response program. One of the signals corresponded to a selling electricity price tariff or feed-in tariff (FIT) to account for the ability of the system to sell energy towards the grid. On the other hand, the second signal corresponded to the buying electricity price tariff to account for the system's energy consumption from the grid. This control scheme allowed to determine the optimal energy consumption of the HP and its flexibility potential to shift its load towards times of low electricity prices. It was concluded that the proposed integrated system will produce a 50 % total energy cost reduction while the operation of the HP for one week in winter will reduce the gas consumption in 53 m3 in a traditional Dutch house.