An energy system, in at least one embodiment, includes an energy production device for production of energy for the energy system with the aid of an working medium, a superconductor for low-loss conduction of electrical energy in the energy system, and a cooling device for cooling of the superconductor with the aid of a liquid phase of a cooling medium. The liquid phase of the cooling medium is, according to at least one embodiment of the invention, produced in the cooling device by condensation of a gaseous phase of the cooling medium, with the condensation of the gaseous phase of the cooling medium taking place by heat transfer from the gaseous phase of the cooling medium to the working medium. The overall efficiency of the energy system can improved by the heat transfer step.