Modeling spectral effects of colored BIPV modules on vertical façades

• A method for estimating spectral effects on colored BIPV façades has been proposed. • Color affects the module’s reflectance and sunlight reaching its solar cells. • Spectral losses depend on façade orientation and slightly on color choice. • South-facing façades showed the most favorable and balanced spectral effects. • There is a need to develop and validate BIPV-specific spectral models. Building-integrated photovoltaics (BIPV) allows renewable energy generation within urban environments. The development of appealing BIPV products, such as colored modules, favors BIPV deployment. However, little attention has been given to the influence of the mounting conditions (i.e., inclination, orientation) and the color choice on the spectral effects that affect the power output of such BIPV installations. As a novelty, this work presents a method suitable for evaluating the spectral effects undergone by colored modules installed in vertical façades as a function of both façade orientation and module color. This method has been applied to three colored crystalline silicon (c-Si) BIPV modules (anthracite, terracotta, and green) for vertical installations in Madrid (Spain) under representative albedo conditions and compared with the results of three spectral models designed for conventional photovoltaic systems (SAPM, First Solar, Caballero). Results suggested that while the effective transmittance (and consequently the power output) was affected by façade orientation and color choice, the latter had a negligible influence on spectral mismatch effects. In contrast, façade orientation was a determinant for predicting some spectral losses throughout the year, which conventional spectral models cannot account for.