Numerical Analysis of Building-Integrated Photovoltaic Design with Thermoelectric Generator and Phase Change Material

Abstract

Building-integrated photovoltaics (BIPVs) are among the most promising systems for achieving green buildings. However, owing to shortcomings such as the lack of solar tracking and the rapid rise in PV surface temperature, there are not many practical cases. Therefore, resolving these shortcomings requires system solutions that can eliminate heat from panels or utilize heat sources to improve system efficiency. Methods of heat dissipation using phase change materials (PCMs), heat fins, thermoelectric devices, air cooling, and water cooling have been proposed and studied. Moreover, many promising studies have been conducted, such as on removing heat from panels that can be used by PCMs to store heat, thereby reducing panel temperature without additional energy consumption. However, owing to problems caused by the low thermal conductivity of PCMs, many studies have combined heat fins and nano-fluid PCMs. In addition, some studies have been conducted on BIPVs with a thermoelectric generator (TEG) or using a working fluid such as water or air to increase the system efficiency. Many studies have proposed and investigated methods of heat recovery using fluids for conventional PV panels, owing to the characteristics of BIPVs installed on the exterior of building walls. Many studies have also explored designs that combine TEGs, which can generate electric power depending on the temperature difference without additional equipment. However, TEGs also have the disadvantage of very low power generation efficiency if they do not achieve a sufficient temperature difference. Therefore, in this study, to address the shortcomings of each application, a BIPV combined with a PCM and TEG (BIPV-TEG-PCM) is proposed. Herein, the appropriate phase change temperature of the PCM and heat pipe design in the PCM container were analyzed through computational fluid dynamics-based simulations.