Curtain wall façades of ETFE and OPV for the Merck Transformer Station

Description

Building envelopes offer opportunities for the use of solar energy. Curtain walls are particularly suitable for the application of photovoltaic modules. Considering the fact that curtain walls are arranged separately in front of the building exterior wall, they allow a relatively simple application of photovoltaic modules, without paying particular attention to the aspects of building physics
(thermal insulation, heat dissipation). Furthermore, a curtain wall enables the access, the connecting and the maintenance on PV-modules from the back. The presented project shows such a successful application. Here, organic photovoltaic (OPV) was applied to ornamental printed and pre-tensioned ETFE films. In combination with the lightweight profiles of aluminum, this resulted in a transparent and aesthetically appealing curtain wall that additionally generates electricity from renewable energies. The façade, finished at the beginning of 2018, is covering the transformer station, a one-story brick building, on the premises of the company MERCK KgaA in Darmstadt, Germany. The façade can be considered, therefore, as the world's first energy-efficient, digitally printed single-layer ETFE curtain wall equipped with OPV-elements. The innovative example shows where development could lead on this path.

The project shows a modular design for curtain wall façades, which consists of the combination of ETFE- film and organic photo-voltaic cells (OPV). Here, three different or-ganic shapes of OPV elements were applied on the mechanically pre-tensioned ETFE film. The 64 membrane modules with aluminum frames form a curtain wall covering four sides of the existing transformer building on the premises of MERCK in Darmstadt in front of a wall made of fired bricks. The selected colours of the digital printing of the ETFE film follow the corporate identity of the company. Due to the relatively small area of the OPV the plant provides only a low power yield.
The small façade is, therefore, a pilot project, that should demonstrate the possibilities of this technology. The direction in which this technology goes is clear: the individual design of modular, aesthetically appealing multifunc-tional curtain walls. Topics include lightness, transparency, aesthetics, careful use of re-sources and solar energy generation. The project uniquely combines aesthetics and multi-functionality. The result is a great archi tec tural work of art with a high innovative standard.

Description of the environmental conditions