Abstract
The present semiconductor thermo-electric-elements integrated into the thermo-electric units, which are commercially available, are not elaborately designed for low temperature-difference operation. Those elements available in the room-temperature range are usually applicable for the temperature-difference around 60K with relatively poor coefficient of performance. For air-conditioning purpose, it is expected for the thermo-electric-energy-conversion to have a high coefficient of performance as well as to have economical advantage because of the low temperature-difference operation.
The paper describes basic and analytical considerations for low temperature-difference operation and also the new design systems desired from viewpoints of the effective and economical exploit of environmental energy. An appropriate design allows the drastic economy in the material and also the drastic improvement in the coefficient of performance and it is possible to put the material, with the presently available figure of merit, in practical use.
The availability of a simple cascade connection is discussed for the operation under some increased temperature-difference. The concept of the cooling or heating systems using a thermoelectric units drived by a solar-cell array will be also proposed and an experimental results will be illustrated.
