09/28/2005, Düsseldorf


Download: web print
Show all


Name Wolfgang Zengerling
  Research & Development, Sustainability
Phone 0049-211-797-9336
Fax 0049-211-798-5598
Email Send email

"Flexible" solar power with industrial adhesives
Henkel bonds the solar roof off the roll

Steeply rising prices for the world's finite resources of petroleum are spurring the development of alternative energy-capturing concepts. The sun is one of the most important sources of energy. It is always there and its power can be tapped without restriction. But only a fraction of its potential has been exploited so far. The idea of integrating flexible solar cells into polymer roofing membranes is a major step toward low-cost and sustainable electricity generation. Henkel, as a system supplier, is playing a major role in establishing this technology, by providing tailor-made high-tech adhesives.
Dark-blue, shimmering, thin-film solar cells consisting of amorphous silicon applied to a fine polymer film - these form the heart of a solar module. A number of bonding challenges had to be mastered before these modules could be joined together and protected from moisture. With its specific expertise, Henkel made it possible to create flexible solar panels for roofing membranes.

California enjoys many hours of sunshine. This not only draws crowds of tourists, but also harbors great potential for environmentally compatible power generation. Solar Integrated Technologies (SIT), a company based in Los Angeles, took advantage of this location factor and developed SmartRoof!, a solar roofing system. Made of flexible, large-area polymer membranes, the solar panels can simply be laid directly off the roll onto flat roofs and connected to any number of other panels.

Although the adhesives account for only a small part of the total volume of the SmartRoof!, the quality of the bonding is ultimately crucial, if the system is to function properly. A team from Henkel Technologies, composed of adhesives experts from Germany and the USA, developed special formulations of polyurethane-based Purmelt hotmelts and polyamide-based Macromelt hotmelts specifically for this application.

Dr. Dwight Heinrich and Dr. Yingjie Li, members of the development team based in the USA and responsible for the hotmelts, explain the multiple requirements the adhesives have to fulfill: "They must bond the different components absolutely reliably; they must satisfy the technical requirements of the production process used to make the system; and they must, above all, be able to durably withstand the stresses of weather conditions and fluctuations in temperature to which the roof is exposed."

The project was also an exceptional challenge from the organizational point of view. Work on the development of the adhesives, the application tests, and the certification and registration procedures was carried out at different places across the globe. "Three time zones, two continents, one team - and we all worked together fantastically," as project manager Kornelia Theissen sums up.

Following the first major contracts in California, SIT is now vigorously targeting international markets to expand its business in solar roofs. Large surfaces in densely populated areas - the flat roofs of warehouses, shopping malls and office buildings - have remained unused up to now because they were not designed to carry the weight of classic solar panels. SmartRoof!, on the other hand, is so light that it opens up completely new perspectives in power generation.

Germany, a country where there is a high level of environmental awareness, is a major marketing objective. The system doesn't need bright Californian sunshine to be effective; it also functions in more moderate daylight. In Germany, each 12 x 3 meter panel can supply up to 1200 kilowatt hours of electricity per year, which is sufficient to cover the average power consumption of a one-person household.

As a system partner to SIT, Henkel's development team is therefore also well equipped to grasp the market opportunities of the future. Henkel is now able to serve the entire value chain in photovoltaics - from cleaners for the production of semiconductor wafers to the adhesives and sealants needed to make the solar modules themselves. A "clean" contribution to sustainable energy generation anywhere in the world.

"Henkel - A Brand like a Friend." Henkel is a leader with brands and technologies that make people's lives easier, better and more beautiful. The Henkel Group operates in three strategic business areas - Home Care, Personal Care, and Adhesives, Sealants and Surface Treatment. In fiscal 2004 the Henkel Group generated sales of 10.592 billion euros. More than 50,000 employees work for the Henkel Group worldwide. People in 125 countries around the world trust in brands and technologies from Henkel.

This document contains forward-looking statements which are based on the current estimates and assumptions made by the corporate management of Henkel KGaA. Forward-looking statements are characterized by the use of words such as expect, intend, plan, predict, assume, believe, estimate, anticipate and similar formulations. Such statements are not to be understood as in any way guaranteeing that those expectations will turn out to be accurate. Future performance and the results actually achieved by Henkel KGaA and its affiliated companies depend on a number of risks and uncertainties and may therefore differ materially from the forward-looking statements. Many of these factors are outside Henkel's control and cannot be accurately estimated in advance, such as the future economic environment and the actions of competitors and others involved in the mar-ketplace. Henkel neither plans nor undertakes to update any forward-looking statements.