Simulation, modeling and experimental performance investigations of novel giant water lens solar thermoelectric generator

World economies are moving rapidly towards ecofriendly technologies like hydrogen fuel cell, electric vehicles, biofuel based generators, etc. As far as thermoelectric power solutions are concerned, presently available thermoelectric generator (TEG) are very expensive, like parabolic dish TEG, Fresnel lens TEG, solar furnace TEG, etc. In this paper, numerical simulation of a Giant Water Lens Solar Thermoelectric Generator (GWLSTEG) system has been carried out, that employs a giant water lens as a solar concentrator and a mid-temperature nanostructured Bi2Te3 thermoelectric module (TEM). Two different software, Sol-Trace for ray tracing through the water lens, and COMSOL-multiphysics for simulation of the Bi2Te3 module, have been used. Following the simulated values, experiment has been conducted by manufacturing a similar giant water lens as a solar concentrator to focus the sun rays on an aluminium receiver plate integrated with Bi2Te3 TEM. Heat flux intensity is noticed to have increased four to five folds, i.e., from 1135 to 4580 W/m2, through the water lens concentrator. Maximum temperature on the hot junction achieved is 498 K and maximum temperature difference of 463 K is achieved between the hot and cold junctions. The system was able to attain a maximum overall system efficiency of 12.04%. Also, it can be noticed that these parameters show maximum values during day time, when the relative humidity and velocity of the air is lowest, i.e., 12.5% at 1400 hrs, and also the maximum power output obtained through the device is 7 W. After experimenting, suggestions have also been given to provide a better software simulation alternative to carry out evaluations and modifications in the process of GWLSTEG functioning in order to get the same results to save time while making it more cost-effective.

Automated summary

This paper presents a numerical simulation and experimental validation of a Giant Water Lens Solar Thermoelectric Generator (GWLSTEG) system. The results show that the system can significantly increase heat flux intensity and achieve a maximum overall system efficiency of 12.04%. Furthermore, the system performs better during the daytime.