Experimental Analysis on Annual Power Generations of Louver-integrated Bi-facial Photovoltaic Modules for Architectural Applications

Abstract

Solar power systems are the most commonly used renewable energy systems for energy self-sufficiency in buildings. In particular, bifacial photovoltaic modules for solar power generation have been researched for their optimal application, as they can generate electricity from two sides using only a single frame. In addition, because the price of a bifacial photovoltaic module is approximately 20% higher than that of a single-sided module, installing bifacial photovoltaic modules in suitable locations on buildings can be economical. To date, most studies have primarily focused on how to increase the amount of power generation from rear cells by arranging materials with high reflectivity on the floors of buildings. In point of fact, when bifacial photovoltaic modules are arranged in an east-west orientation, the maximum amount of power can be obtained in the mornings and afternoons. However, when these modules are installed in buildings in this orientation, a shadow is produced on the building surface according to the trajectory of the sun. In addition, when photovoltaic modules are used in the building envelope, the amount of power generation is often reduced because of this shadow. Nevertheless, even when considering this reduction in power generation, if the total power generation is higher than when photovoltaic modules are installed only vertically, the self-sufficiency rates of buildings can be improved. In this study, the shadow of a bifacial photovoltaic module was simulated using vertical photovoltaic modules to consider the possibilities of architectural application of bifacial photovoltaic modules.