Abstract
During the last decade, photovoltaic generators were well-integrated into buildings along with the development of photovoltaic technologies. There are, however, some obstacles to the spread of building integrated photovoltaics (BIPV), especially to the use for the attachment to vertical walls. In Japan, the solar altitude angles in summer is high, and therefore, the decrease of the power generation from PVs on vertical walls is significant in summer. In the study, we develop a novel concentration power generator which is integrated into double facades of buildings. The system consists of a nonimaging Fresnel lens type solar concentrator for the outer facade, and solar cells attached on the surface of the inner wall. The Fresnel lens was designed to accept the transition of the position of the sun during the daytime without tracking. The paper describes the design strategies and the results of simulation by the ray-tracing method.
