Thermoelectric generator designs

The conversion of heat to electric energy by the phenomena of thermoelectricity has been considered for many years as a desirable means of obtaining pure d-c power which does not require moving parts and as much maintenance as presently exists, especially in the present types of generators that are driven by gasoline engines. As near as can be determined, the earliest observations of the thermoelectric effect were made by Seebeck in the early part of the 18th century. During the 18th century many inventors attempted to produce a thermocouple that could be incorporated into a generator that would be accepted generally by the public as a practical power source. In most instances, however, these designs resulted in conversion units that were wasteful of fuel and were large and cumbersome, as well as unreliable and expensive to construct. Toward the end of the 18th century, as rotating equipment for the production of a-c and d-c power became more universal, further attempts to perfect thermoelectric generators received less impetus. There seems no thermoelectric generator that has been developed that approaches the efficiency of present conversion units, such as motor generator sets and gasoline-engine-driven generators. A close examination of the past work has indicated that the approach to the solution of the problem was not always sound, mostly because the scientific tools with which the researchers worked were not as highly developed or as plentiful as they are today, the choice of materials not as large, and the understanding of material structures not as well understood. It is true, even today, that the understanding of material structure is not too clearly understood when working with materials other than metals, but is sufficiently well advanced to set up methods by which a scientific approach can be laid out.