Energy needs poses a major national problem, which increasingly will affect Thailand’s development. Various fuels currently used to produce electricity such as oil, natural gas and coal, are becoming scarcer and will disappear in the future. “Alternative energy” thus will play an increasing role, with thermoelectrics a possibility.
Thermoelectric material is that which can change heat electricity to electricity, but utilizing the temperature difference between two points. Electrons travel from the point of higher temperature to that of lower temperature on the material, causing electrical polarity and potential difference, leading to useful electrical energy. Today thermoelectric materials are still imported into Thailand, with very limited applications, since the working principles of this material are not well known or understood. Thus study towards improvement and development of such thermoelectric material would be useful for many applications, as to lead to further alternative energy sources in the future.
Khon Kaen University and SLRI researchers worked to gether to study the structure of thermoelectric material with metal injected in Ca2Co2O4 (calcium cobalt oxide) through x-ray absorption spectroscopy, a technique for analysis of type of atoms, neighboring atoms and oxidation states of the atoms. The technique provides knowledge of the location of the metal in the Ca2Co2O4, to find ways for improvement of the properties of thermalelectric materials.
Currently, thermoelectric materials are applied in many fields:
· Energy saving vehicles, with thermoelectric materials installed in the exhaust pipe. The side in contact with the exhaust pipe would be of high temperature, while the side in contact with the external air would be of low temperature. The temperature difference would produce electric current for the vehicle.
· Smart phone battery charging by using bodily movement, such as walking or running.
This research has produced a ZT value, a measurement of thermoelectric material efficiency, that has increased by 35%. Materials of this type have been successfully produced as two modules: 1. Changing heat to electricity, by using heat loss applieances, usable in cold countries, such as of Europe; and 2. Converting electricity to heat or cold, able to use in conjunction with CFCs in refrigerators.