PV Flexibles - Photovoltaics Integrated in Translucent PTFE-and Transparent ETFE-Membranes Structures
Creators: name: Cremers, J.
name: Lausch, F.
Publisher: name: WIP-Munich
Year: 2008
Subjects: PV Systems
PV Applications in the Built Environment

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 3520-3522
description: The great variety of the projects completed in type and scale using textile materials as a building envelope shows the enormous potential of these kind of constructions which in its primordial form of appearance are among the oldest of mankind - their predecessors, animal skins, have been used to construct the first kind of building envelopes, namely tents. Earlier applications of textile materials have served the purpose to keep off sun, wind, rain and snow while offering the advantage of enormous span widths and a great variety of shapes. The development of high performance membrane and film materials on the basis of fluoropolymers, e.g. translucent membrane material like PTFE (poly tetrafluoroethylene) coated glass fibres or transparent foils made of a copolymer of ethylene and tetrafluoroethylene (ETFE) were milestones in the search for appropriate materials for the building envelope. SolarNext together with its sister company Hightex are to tap and even broaden the future potential of membrane applications by investigating and developing applicable solar technology. This includes the work on passive measures such as the further improvement of solar gain control and heat protection by functional coatings, the integration of translucent thermal insulation, acoustic and daylight-properties. For the 23rd European Photovoltaic Solar Energy Conference and Exhibition, we would like to present one of our most challenging ongoing developments and report experiences with the first prototype applications which are the first of its kind worldwide [1]: Fully integrated and flexible photovoltaics (PV Flexibles) into translucent membrane and transparent film structures will not only provide energy but also help to control solar gains. The technology being developed is
flexible amorphous silicon ("a-Si") thin-film photovoltaics embedded into ETFE-foil and applied on PTFE glass membrane. ETFE is commonly used in the building industry for translucent and even transparent envelope
constructions for decades now and has proved to be of long-term-value as it is very stable against weathering influence including UV-irradiation. It is not measurably degrading and keeps its unique surface qualities (antiadhesion,
clear and high transparency) over time. The complex laminates of ETFE and photovoltaics (PV) can be joined to larger sheets and be applied in single-layer roofs or facades. But they can also be used to replace for example the top-layer in pneumatic membrane cushions. Compared to free-spanning single-layer applications these inflatable structures are relatively new as an established subject of architecture (and not only as a piece of 'engineering structure') - they have entered the architectural world only in the early 1960s [2]. The technology developed will help architects and designers providing a fully integrated PV solution (BIPV) for a market segment where there has not been a PV option before. The membrane market is continously and strongly
increasing over the last decades. Nowadays, most of the newly built stadia in the world are covered with large membrane roofs as this is a very economic solution to shelter large spaces featuring natural light at a very high comfort levels. Today, these large roof and facade areas can be used to also provide clean electrical power by the integration of PV as a shading system.