Colored optic filters on c‐Si IBC solar cells for building integrated photovoltaic applications

Abstract

Building Integrated Photovoltaic systems can produce a significant portion of the energy demand of urban areas. Despite their potential, they remain a niche technology that architects and project engineers still find esthetically limited. The dark blue or black color of standard photovoltaic panels is considered inappropriate for restoration projects of historic buildings and represents a major constraint on the development of new projects. This work will provide insight into how the use of optic filters can offer new pathways for architectural acceptance of photovoltaic panels. Optic filters selectively reflect or transmit light by interference and can be designed and fabricated using cost-effective and industrially compatible processes. By using in-house developed ray tracing software coupled with TCAD Sentaurus, more than 400 colors were obtained, and their impact on the opto-electrical performance of interdigitated back-contacted solar cells was studied. Results show a maximum efficiency loss of 1.6% absolute at the perpendicular incidence of light on the range of obtained colors when compared with a standard dark blue solar cell. Simulations for different angles of incidence showed that the current reduction on the standard device could be modeled using a cosine relationship. The colored cells, however, deviated significantly from this relationship. We propose that the angular behavior of any cell (colored or standard) could be simulated by modifying the effective irradiance with scaling factors equal to the ratios of the photogenerated current at any angle with respect to the value at normal incidence. We demonstrate that this approach accurately models the effect of the color filter and allows for an easy transition from a bare cell to an encapsulated one. Due to the spectral effect of the filter, we developed both a spectrally resolved optical model and a two-dimensional finite volume transient thermal model. In case of the optical model, we demonstrate an accuracy in the prediction of the reflectance produced by the color with values of mean bias error (MBE) between 2.0% and 3.9%. As for the thermal model, it was validated by first analyzing a standard model under conditions of nominal operating cell

Optimal Design of Multilayer Optical Color Filters for Building‐Integrated Photovoltaic (BIPV) Applications

“…The electrical models presented in ref. [24] were validated on first instance via comparisons between the two-diode model approximation with simulations carried out on Sentaurus TCAD. The thermal model was validated by comparing the predicted temperature of a standard PV module with measurements carried out on non-colored solar modules.…”

Concepts for heat utilization and passive cooling techniques to improve reliability and performance of Building Integrated Photovoltaics (BIPV)

“…This prediction implies peculiar modeling challenges, as optical filters have particular spectral behavior that changes depending on the angle of incidence of light. All the mathematical details of the spectral and thermal models can be found in [12].…”

Low Breakdown Voltage Solar Cells for Shading Tolerant Photovoltaic Modules

“…The cell temperature was modeled using the 2D thermal model described and validated by Ortiz Lizcano et al 62 As shown in Figure S1, the thermal model is coupled with the electrical model to account for the electrical power extracted from the solar cells.…”