Climate response of a BiPV facade system enhanced with latent PCM-based thermal energy storage

Building-integrated photovoltaic (BiPV) systems applied within a building envelope exhibit limited efficiency and durability due to their insufficient cooling capabilities. Thus, the need to decrease their operating temperature and increase overall electricity production poses relevant research challenges. The application of a phase change material (PCM) to the rear side of a PV module can provide both a decrease in PV panel temperature and thermal energy storage as well. The objective of the presented study is to identify the climate response of latent thermal energy storage (TES) integrated into a ventilated photovoltaic (PV) facade system. The main attention is focused on the thermophysical properties of the employed PCM in terms of the utilization of its overall latent heat capacity through the diurnal cycle of a day in the context of the mutual interaction between incident solar radiation and outside air temperature. A comparative investigation was conducted using experimental measurements taken during outdoor climate tests with the aim of determining the real performance of the facade system. The experimental results revealed that the effect on PV panel operating temperature of installing the selected PCM on the rear side of the panels is significant mainly at midday when high solar radiation is present. (C) 2020 Elsevier Ltd. All rights reserved.