Investigation of Solar Hybrid Electric/Thermal System with Radiation Concentrator and Thermoelectric Generator

Edgar Arturo Chávez Urbiola,Yuri Vorobiev

doi:10.1155/2013/704087

Abstract

An experimental study of a solar-concentrating system based on thermoelectric generators (TEGs) was performed. The system included an electrical generating unit with 6 serially connected TEGs using a traditional semiconductor material, Bi2Te3, which was illuminated by concentrated solar radiation on one side and cooled by running water on the other side. A sun-tracking concentrator with a mosaic set of mirrors was used; its orientation towards the sun was achieved with two pairs of radiation sensors, a differential amplifier, and two servomotors. The hot side of the TEGs at midday has a temperature of around 200°C, and the cold side is approximately 50°C. The thermosiphon cooling system was designed to absorb the heat passing through the TEGs and provide optimal working conditions. The system generates 20 W of electrical energy and 200 W of thermal energy stored in water with a temperature of around 50°C. The hybrid system studied can be considered as an alternative to photovoltaic/thermal systems, especially in countries with abundant solar radiation, such as Mexico, China, and India.

Highlights

Solar hybrid electric/thermal systems using photovoltaic (PV) panels combined with a water/air-filled heat extracting unit were designed and studied in many laboratories during the last three decades [1,2,3,4,5,6,7,8,9,10] and are widely used throughout the world (England, Canada, China, Greece, India, and so forth)
Some investigations were made [11,12,13,14,15,16] into the possibilities of using thermoelectric generators (TEGs) in solar hybrid systems, with the conclusion that TEGs can be successfully used in these systems instead of PV panels or together with them
A schematic of the system is shown in Figure 1 where the solar radiation flux (1) is concentrated by the mosaic mirror (2) onto the electric/thermal generating unit (3) consisting of a radiation absorber, TEG array, and a cooling plate that is in direct contact with water-circulating copper tubes

Summary

Introduction

Solar hybrid electric/thermal systems using photovoltaic (PV) panels combined with a water/air-filled heat extracting unit were designed and studied in many laboratories during the last three decades [1,2,3,4,5,6,7,8,9,10] and are widely used throughout the world (England, Canada, China, Greece, India, and so forth). We describe the construction and detailed experimental investigation of one of the hybrid systems analyzed in the above-mentioned paper [14], namely, the system with a solar radiation concentrator, TEG, and water-filled heat extracting unit. The experiments were performed in Queretaro, Mexico, at 20∘ of northern latitude, in March 2012

Description of the Hybrid System

Calculation of Thermosiphon Loop

Experimental Results

Conclusions