An energy system having a fuel cell arrangement, wherein the fuel cell arrangement has at least one fuel cell and the fuel cell arrangement has at least one first electrical contact and at least one second electrical contact for tapping off electrically generated energy of the fuel cell arrangement. An electrical component for warming up the fuel cell arrangement is electrically connectable between the first electrical contact and the second electrical contact. At least some of the electrical energy flow which is necessary to release the thermal energy can be fed back to the energy system by the electrical component.