Electric Power Generation from Solar Pond Using Combination of Thermosyphon and Thermoelectric Modules

Abstract

Salinity-gradient solar pond is one type of solar collector with the ability to store thermal energy for long period of time and lower cost of construction compared with the other type of solar collector. It can collect and store solar heat at temperatures up to 80°C. A system in which heat from the lower zone is transferred to the hot surface of the thermoelectric modules using gravity- assisted heat pipes as thermosyphons has been investigated experimentally.The temperature difference between the lower convective zone and the upper convective zone is applied across the hot and cold surfaces of the thermoelectric modules. In the salinity gradient solar pond, a insulated solar pond with a surface area of 7 m2 and a depth of 1.3 m was built at Rajamangala University of Technology Isan Khon Kaen Campus,Thailand to conduct performance experiments. From the results of experiment by using water as working fluid, the temperature of the solar pond in lower convective zone is at 50°C.It can be seen that the thermoelectric is able to generate electricity at 36.25mV. Using R134a as a working fluid, the temperature of heat pond in lower convective zone is at 41°C.Due to this, thermoelectric generates electricity at 234.25mV.. Research results in the present work indicate that there is a significant potential for electric power generation from small solar ponds through a simple and passive device incorporating thermosyphons and thermoelectric cells.