Predicting color and short-circuit current of colored BIPV modules

T Gewohn,B Lim,R Brendel,C Schinke

doi:10.1063/5.0063140

Abstract

Photovoltaic modules for façade integration should have a widely modifiable appearance to adjust to the architect’s requirements. However, architects today usually have only a limited number of already manufactured samples to choose from. Changing the color will also change the photovoltaic yield. Therefore, it would be helpful to have a procedure that allows us to determine the appearance and expected yield in advance of module fabrication. We present such a method for creating a digital prototype of a colored building integrated photovoltaic module. Using reflectance and external quantum efficiency measurements of eight colored modules, we simulate the appearance and respective energy yield for arbitrary module colors. We validate our predictions for 29 different colored modules. We use textiles that have been colored by printing and laminate them onto the modules to change the appearance of the modules. However, our digital prototyping model is also applicable to other coloring techniques. We achieve an average color difference of ΔE00 = 1.34 between predicted and measured colors, which is barely perceptible to the human eye. The predicted short-circuit current density of the digital prototype deviates on average less than 1% from the measured one.

Highlights

IntroductionDue to climate and energy targets in the building sector, building integrated photovoltaics (BIPV) are developing from a niche product to an important market. As a result of the lower costs for photovoltaic modules, the costs of standard BIPV modules are in the same price segment as non-PV façade and roof elements. Numerous methods have been developed to alter the appearance of BIPV modules. These techniques differ in terms of color impression, energy yield, and costs
Numerous methods have been developed to alter the appearance of building integrated photovoltaics (BIPV) modules
We present a digital prototype of a PV module, i.e., a mathematical model for predicting the appearance and yield of an arbitrarily colored PV module whose appearance has been altered by laminating colored textiles (CoTex) onto the front glass of the module

Summary

Introduction

Due to climate and energy targets in the building sector, building integrated photovoltaics (BIPV) are developing from a niche product to an important market. As a result of the lower costs for photovoltaic modules, the costs of standard BIPV modules are in the same price segment as non-PV façade and roof elements. Numerous methods have been developed to alter the appearance of BIPV modules. These techniques differ in terms of color impression, energy yield, and costs. Due to climate and energy targets in the building sector, building integrated photovoltaics (BIPV) are developing from a niche product to an important market.. As a result of the lower costs for photovoltaic modules, the costs of standard BIPV modules are in the same price segment as non-PV façade and roof elements.. Numerous methods have been developed to alter the appearance of BIPV modules.. Numerous methods have been developed to alter the appearance of BIPV modules.1 These techniques differ in terms of color impression, energy yield, and costs. The focus is often to hide the solar cells and to integrate the PV modules into the building envelope as unobtrusively as possible. Coloring the modules implies a reduction of the energy yield because a part of the incident light is reflected and is not used for energy generation

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Discussion

Conclusion