A study on incorporation of thermoelectric modules with evacuated-tube heat-pipe solar collectors

This paper presents an experimental and analytical study on incorporation of thermoelectric modules with glass evacuated-tube heat-pipe solar collectors. The integrated solar heat-pipe/thermoelectric module (SHP-TE) can be used for combined water heating and electricity generation. The experimental prototype unit comprises a glass evacuated-tube, a heat-pipe and a thermoelectric module with its one side attached to the condensation section of the heat-pipe and other side attached to a water channel. The heat-pipe transfers the solar heat absorbed within the glass evacuated-tube to the thermoelectric module. Under the condition of given solar irradiation and water temperature, the current, voltage and power outputs of the thermoelectric module are given for variable external electrical resistance. An analytical model of the prototype unit is presented to relate its thermal and electrical efficiencies with the solar irradiation, ambient temperature, water temperature, areas of the glass evacuated-tube and the thermoelectric module, and the length, cross-section area and number of thermoelements in the thermoelectric module. The analytic model is validated against the experimental data before it is used to optimize the design and operating parameters of the prototype for combined water heating and additional electricity generation. (C) 2011 Elsevier Ltd. All rights reserved.