NOVELTY - The thermoelectric generator comprises a pipe (32), a thermoelectric module (40), and a phase change material or alloy composed of phase change material. The pipe conducts a hot medium. The phase change material: comprises an inorganic metal salt having a melting point of 250-1700 degrees C, salt mixtures, which form the inorganic metal salts with double, triple and quadruple or quintuple eutectics, and a metal alloy with a melting point of 200-1800 degrees C; and is formed in a piece or as a thin layer and as an encapsulation around the pipe and/or the thermoelectric module.    USE - The thermoelectric generator is useful in a motor vehicle and a power plant (all claimed), for microelectronic components, a geothermal power and a domestic and industrial waste heat, and as hybrid systems in conjunction with photovoltaic plants.    ADVANTAGE - The cost-effective thermoelectric generator exhibits high efficiency and long lifespan.    DETAILED DESCRIPTION - The thermoelectric generator comprises a pipe (32), a thermoelectric module (40), and a phase change material or alloy composed of phase change material. The pipe conducts a hot medium. The phase change material: comprises an inorganic metal salt having a melting point of 250-1700 degrees C, salt mixtures, which form the inorganic metal salts with double, triple and quadruple or quintuple eutectics, and a metal alloy with a melting point of 200-1800 degrees C; is formed in a piece or as a thin layer and as an encapsulation around the pipe and/or the thermoelectric module; is installed at any position in an off-gas line, on/in a manifold, on/in an off-gas recycle pipe, on/in an off-gas pipe, on/in a silencer and/or on/in a rear silencer; and is present in a package. A layer of phase change material is introduced between the pipe and a hot side of the thermoelectric module. The phase change material is: integrated in the thermoelectric modules or in the thermoelectric generator; applied on an inner side (48) of the pipe; introduced separately between the pipe and the thermoelectric module; introduced over a full area or in sections, parallel or at right angles to the length of the pipe between the thermoelectric module and the pipe; or inserted directly or indirectly between a heat source and the hot side of the thermoelectric modules. A heat exchanger has an encapsulation or the package, and protects the thermoelectric module of the thermoelectric generator from overheating. The off-gas flows through the off-gas pipe. The phase change material applied on the package. The package applied on an outer surface of the pipe through which hot off-gas flows or applied on the thermoelectric module. An encapsulation thickness within the package of phase change material is constant in relation to embedding of the thermoelectric module or especially between the outer surface of the off-gas pipe, which conducts the hot off-gas flow and the inside of the thermoelectric module is greater. An INDEPENDENT CLAIM is included for a process for producing a thermoelectric generator.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a thermoelectric generator.    Pipe (32)    Cross section of a pipe (34)    Thermoelectric module (40)    Cooling lines (46)    Inner side of a pipe. (48)