Experimental identification of effects of using dual airflow path on the performance of roof-type BAPV system

Abstract

Photovoltaic (PV) modules attached to the building exterior have a problem with efficiency reduction due to temperature increase of the modules. To minimize the temperature increase of the PV modules, this study proposes a passive cooling technology that can improve the natural cooling performance by creating dual airflow paths for the building applied photovoltaic (BAPV) system. To experimentally verify this natural cooling technology (NCT), a BAPV system with the NCT and a conventional BAPV system of the same capacity were constructed, and their power-generation performances based on the three-month experimental results in a cold weather season were compared under the same environmental conditions. The BAPV system with the NCT on average generated 4.5% more power than the conventional BAPV system. The performance ratio (PR) analysis showed that the average PR value of the BAPV system with the NCT was 87.1%, which was approximately 5.5% higher than that of the conventional BAPV system. Results suggest that the proposed NCT improved the airflow on the backside of the PV modules and supplied fresh air to all of them, and hence, it improved the cooling performance and induced relatively lower module temperatures. A correlation between the electric power generated and the solar irradiance was derived for each system. © 2020 Elsevier B.V.