A multifunctional ETFE module for sustainable façade lighting: Design, manufacturing and monitoring

Abstract This paper summarizes initial activities developed under the ETFE-MFM project, an European EU-FP7 funded initiative focused on the design, manufacturing and testing of a smart solution for current facade multifunctional requirements in the building sector; as energy harvesting, glazing, thermal isolation and lighting. The system is based on Ethylene Tetrafluoroethylene (ETFE), a polymeric material with increasing interest in textile architecture. The aim of this work is to provide a standardized ETFE module acting as a flexible LED display harvested by photovoltaics. In this way, LED strips, organic solar cells and flexible electronics have been embedded in an ETFE structure and a lamination process has been developed using Ethyl Vinyl Acetate (EVA) as interlayer material. This process has been optimized in order to provide good optical and mechanical performance without affecting the functionality of the components. The resulting ETFE membrane has been framed leading to a 1.5 × 1.5 m2 prototype that it has been vertically installed in a building roof for monitoring and testing from Nov. 1st, 2016 to Sept. 30th, 2017. As main result, it can be said that the module had an average production of 43.45Wh per day with maximum values between 80 Wh and 90 Wh. Taking into account that monitored energy consumption for video displaying is 35.32 W, this yields to an average self-standing mode of 74 min. Up to our knowledge, this constitutes a new approach to design and manufacture a textile architecture module with these features.