Exergetic analysis of a solar thermoelectric generator

Recently, thermoelectric modules have been considered as possible replacement to solar photovoltaic system due to its potential for combined heat and power. In the designs of solar thermoelectric cogeneration systems, a careful compromise has to be made between thermal energy and electrical power. For practical purposes, electrical power is preferred over heat energy. However, due to the current low conversion efficiencies of thermoelectric materials, increasing electrical power generation causes the overall combined efficiency to suffer. This study proposes an exergetic analysis of combined heat and power solar thermoelectric systems to maximize exergetic efficiency. The modeling is based on the previously investigated design of a solar thermoelectric generator for residential combined heat and power generation. The working conditions (cold side reservoir temperature and solar concentration) are varied to maximize exergetic efficiency without sacrificing too much electricity generation. The module geometry for thermal load matching is also suggested.