The invention relates to a method for saving energy in an extrusion line comprising at least one extruder, an extrusion tool, a cooling section, and an outlet, energy being applied in the form of heat to a plastic for plasticization at least in the extruder, in order to produce a profile (8), and the heat being removed again from the profile (8) after a forming process, at least in the cooling section, in order to achieve shape stability of the same. According to the invention, at least one part of the removed heat is converted to mechanical energy and fed back into the extrusion process. At least, the heat taken from the cooling section is transmitted to thermal machines (11, 12) through a water circuit (13), and the thermal machines (11, 12) drive the pump. The invention further relates to a corresponding device.