Experimental investigation on thermoelectric generator of micro hybrid power source

The micro power system, which is composed of photovoltaic solar cell, heat conductor, thermoelectric generator (TEG) module and fin heat sink has been developed in our laboratory. A photovoltaic silicon solar cell of the P-N junction type is sensitive to radiant energy of wavelength from 5,000 Å to 12,000 Å. Radiation under and within this range is converted not only into electric energy but also into heat energy. The wavelength longer than this range is also converted into heat energy, which degrades the conversion efficiency of the solar cell. TEG produces electrical power from temperature difference via Seebeck effect that can be put under the solar cell to absorb the heat. The heat energy can be converted into electrical power. It was found that when TEG surface area was 150mm×60mm, it could generate 0.24V output voltage and 4.18mA short circuit at ambient temperature varying between 5-10°C at winter. It also could generate 1.3V output voltage and 16mA short circuit at ambient temperature varying between 30-36°C at summer. In fact we can use a dc-dc boost up converter to enlarge the output voltage to meet the requirements of wireless sensor network nodes or its recharging battery. It will be an alternative power source for many portable electronic types of equipment.