Jury Statement: The application of PV on platform roofs is an ideal field of application with many advantages; multifunctionality: apart from weather protection, electricity production is combined with sun protection of the railroad area; reduction of artificial lighting due to semi-transparent modules; this project has great publicity; it should be pioneering and a model for other platforms and similar applications; it would be desirable if this becomes the standard for public stations.
Future technology
Perovskite solar cells show efficiencies of over 25 percent in the laboratory. However, this is still only true on a small scale: "In addition to stability, a central hurdle for the market entry of the technology is to transfer the high efficiency achieved on small surfaces to large surfaces," says tenure-track professor Ulrich W. Paetzold from the KIT Institute of Microstructure Technology (IMT). SUNOVATION has already been working with various coloring processes for many years. For example, the colored solar modules of the currently largest solar plant in the world in Mecca come from the German manufacturer SUNOVATION. Currently, high-performance colored modules for solar facades are produced with crystalline cells and colored coating processes, since the best yields can still be achieved with this technology (see "ColorQuant" collection).
Förderkennzahl Project PrintPero: 03SF0557B
Details KIT-Zentrum Energie: www.energie.kit.edu
Details SUNOVATION: www.sunovation.de
Through a combination of "optimizing PV performance" and "minimizing power losses through coloring", SUNOVATION masters the balancing act between module optics and module performance with this new color collection: coloring of photovoltaic modules inevitably leads to a certain reduction in PV performance. The challenge in the development and production of colored solar modules is to minimize this undesirable influence. SUNOVATION eFORM unichrome glass-glass-modules are configured individually according to customer requirements. A special manufacturing process (SCET - Sunovation Cell Embedding Technology) enables the production of precisely fitting modules with individual glass structures. The use of high-performance crystalline PV cells, integrated diodes and an individually optimized cell layout results in maximum PV-output/m². Combined with a specially developed technology for coloring, the exclusive collection of high-performance colored PV modules for building integration has been created. Based on coloring by interference, the sunlight is split up like in a prism. Light needed to generate energy continues to reach the PV cell through the colored layers, while the wavelengths responsible for the coloring are selectively reflected. The influence of the coloring on the performance of the PV cells is reduced to a minimum by using this technology.
The colored glass-glass modules are used in particular in solar facades. "In the last two years, we have seen a significant increase in demand from architects and building owners for aesthetically pleasing PV-modules that can also make a relevant contribution to energy generation in the building envelope," says Heribert Ley, Managing Director of SUNOVATION. "The "ColorQuant" collection is therefore very well received by our customers. The first facade projects with new color shades are already ordered and will be realized in 2022." Unlike other colored PV modules, the integrated PV cells remain invisible in all weather conditions and retain their colored glass appearance from all viewing angles.
An exclusive 6,000 m² glass roof made of building-integrated photovoltaics with an output of ~1.2 MWp replaces the original glass roof. Renzo Piano chose semi-transparent glass-glass modules from Sunovation, which were individually manufactured according to his designs. With over 300 different geometries, the glass-glass modules were precisely adapted to the existing historical building structure. The design of the glass-glass modules played a fundamental role alongside the technical specifications. In order to perfectly integrate them into his design of a light-flooded building, Renzo Piano opted for a degree of transparency of ~20% as well as an individual design of the PV cells. Their appearance was refined in shape and color by imprints in shades of gray and white on different glass layers. The realization of this exclusive design was made possible by the special production process of the module manufacturer Sunovation, which offers the greatest variety of individualization options in the field of customized BIPV modules.
Photo: © Michel Denancé