Concentrated Photovoltaic/Thermal Hybrid System Coupled with a Thermoelectric Generator

Abdelrahman Lashin,Mohammad Al Turkestani,Mohamed Sabry

doi:10.3390/en12132623

Abstract

Concentrator photovoltaic (CPV) systems have displayed an important cost reduction and in the next few years could offer a competitive cost advantage compared to that of flat plate PV systems. Such CPV systems require some cooling methods to overcome high operating temperatures, which reduces their efficiency significantly. On the other hand, thermoelectric generators (TEG) are devices that convert thermal energy directly to electrical energy, provided that there is a temperature difference between its two faces. A hybrid concentrator photovoltaic/thermal (CPV/T) system is proposed in this work. Such a system uses TEG in a two-fold manner: to passively cool down the CPV cell in order to maintain its power conversion efficiency in such high temperature conditions, and to use the accumulated thermal energy to generate electrical energy, which is added to the system’s total power output. Two types of solar cells were investigated, namely, Ga0.35In0.65P/Ga0.83In0.17As with efficiency an of 28% at 250X, and a Laser Grooved Buried Contact (LGBC) silicon concentrator PV cell with an efficiency of 18.3% at 40X. These cells are assumed to be coupled with two TEGs of the same type but with a different number of junctions. Experimental results showed that coupling TEG modules to a CPV system could be a useful method for enhancing the overall output power, provided that PV cells are chosen with a low efficiency temperature coefficient and high PV performance. Also, TEG modules have to be chosen with a high figure of merit. Moreover, the operating optical concentration ratio, as well as the covered area of the TEG, have to be optimized in order to maximize the total system output.

Highlights

Photovoltaic energy conversion has already become one of the most reliable energy resources.Further reduction of the system costs is a must in order to fulfill the increasing demand for energy all over the world
The predicted output power of the thermoelectric generators (TEG) under partial covering of its hot surface with thermal energy is investigated without involving PV cells
32% and 18% for cells coupled to TEG1 and TEG2, respectively

Summary

Introduction

Photovoltaic energy conversion has already become one of the most reliable energy resources.Further reduction of the system costs is a must in order to fulfill the increasing demand for energy all over the world. In order to achieve such a cost reduction, the solar cell output power could be increased by the use of either stationary or tracking solar concentrator subsystems [1]. The operating temperature of PV cells plays an important role in determining their electrical output because part of the incident solar energy is converted into electricity while the remaining part is converted into heat [2,3,4,5]. This adds another disadvantage to using such concentrating systems because of the elevated PV cell’s temperature

Results

Discussion

Conclusion