Application of transparent dye-sensitized solar cells to building integrated photovoltaic systems

Dye-sensitized solar cell (DSSC) is one of the most promising photovoltaic systems for building integration (BIPV). DSSC can be transparent with various degrees of transparency, which makes it suitable for window application in buildings. In this study, we investigate the relationship between the transparency, the efficiency of DSSC and the overall energy efficiency of a building when DSSC is applied as window system. It is shown that while the efficiency of less transparent DSSC is generally higher due to higher short circuit current density (Jsc) from the thick electrode, it does not necessarily maximize the overall energy efficiency of a building. This is because lighting conditions of the building varies with the transparency of the window. The optimum condition should be carefully considered with the transparency of window as computationally simulated in terms of energy generation and consumption. We also find that different orientations of window in the building affect the optimum conditions of DSSC.