New photovoltaic system exploited by the unique characteristics in thin film Si modules

Thin-film silicon PV modules prepared on a glass substrate by the plasma CVD are able to apply new installation methods compared with conventional PV systems. As one of the applications, see-through PV module can be produced with high productivity, because the thin-film silicon layer is easily removed by precise laser technique. This see-through PV module is suitable for building integration materials, such as windows and skylight structures. Furthermore, it can act as the visual screen at night. On the other hand, the thin film silicon PV modules can be installed in a low angle of inclination on a flat rooftop of buildings. By this method, the whole rooftop can be covered tight and close with PV modules and it shuts out direct irradiation of sunlight to the rooftop. This new installation PV system is effective in preventing temperature rise of the rooftop and saving energy costs of air conditioners in addition to power generation. Furthermore, we can easily combine a green roof system with this PV system.