The concept of Building Integrated Photovoltaic (BIPV) is the most promising method to use built space for solar energy capture,  conversion and distribution. However, BIPV is limited to the rooftop space due to the serious constraints of the standard module;  mainly the components are opaque and have a standard size and shape. This limits its use in the vertical built space of skyscrapers that  requires aesthetic appearance and on-demand transparency for windows to guide daylight into the built space. The present invention  discloses a hybrid planar light concentrator (HPLC) system that can fully exploit the vertical built space for energy generation by  offering enhanced lateral light concentration to the photovoltaic (PV) cell, and adaptable transparency. Theoretical calculation shows  that a typical HPLC system with a geometric light concentration ratio of 16.7 can generate 0.67 times energy in its opaque mode when  compared with a rooftop PV cells of the same area, in addition to this, the photovoltaic material consumption is reduced to 16.7 times  for attaining same energy output. Hence, the disclosed HPLC system can function as a dynamic smart window that can control  incident light transmission and at the same time generate electricity using the laterally directed light. Apart from its potential in BIPV,  the HPLC system can also find possible applications as smart windows for displays/mirrors, illuminance controller, and on-demand  privacy settings.