With cost cutting in mind the photovoltaics industry increasingly relies on automation expecting it to bring about sustained high product quality and increased productivity. Industrial robots feed and discharge solar cell production lines and sort the finished components by pick-and-place processes. They handle glass panes, cut films and foils and assemble frames around solar modules and have recently even started installing junction boxes. Be it at Q-Cells in Bitterfeld, at Conergy in Frankfurt/Oder or Bosch Solar Energy in Erfurt – most production lines in the solar sector are highly automated these days.

For a good reason: “Here in Europe we have to increase capacities to remain competitive,” says Carsten Busch, Head of the Solar Unit at ABB Automation in Friedberg, who adds that price pressure is enormous. If we are to keep manufacturing modules in Germany then robots will have to be used for even more tasks in future. “The automotive industry has proven that successful manufacturing is possible here in this country.” The solar sector is increasingly interested in manufacturing concepts that have “empowered” the likes of Mercedes, Porsche or BMW. Many manufacturers of automation technology boast precisely this know-how.

ABB offers robots for nearly all segments of cell and module production – ranging from FlexPickers for transferring silicon cells and lines for handling and conveying sheet glass to systems for packaging and palletising the finished solar modules. Busch emphasises that “In the solar sector the prime objective is not to save labour costs.” But if large product volumes of the same high quality are to be manufactured robots simply outperform human beings. A case in point being the cross-soldering of so-called strings, i.e. strings of already connected solar cells. “When just one single cross-soldering is not 100% perfect this affects the efficiency of the entire module,” explains the Manager. A single dry soldered joint can even render a complete solar module useless. This is why more and more producers are taking to the fully automatic soldering of cells and strings.

Automotive Industry as a Role Model

“Robots never have a bad day,” confirms Hartmut Wirths at the industrial enterprise Bosch Rexroth, and goes on to say: “Furthermore, the machine does not care where it stands and always gives you consistent quality.” Other benefits are the readiness for use 24/7 and the enormous speed of robots: “Only with automation you can achieve the high production volumes and short cycle times needed for mass production of solar cells,” says Carsten Busch. Robots also bring higher efficiency in the thin-film solar segment: “Glass sheets are becoming bigger and also thinner – and hence more sensitive. Each piece of glass that is destroyed in the process costs money.”

Robots have already become the gold standard worldwide for the production of wafers, i.e. thin silicon slices cut from ingots. “If an employee drops a silicon ingot like this it costs the company nearly US$ 2,000,” says Busch and explains that the material is brittle and therefore breaks into many pieces. Man remains an instability factor. Which is why ingots are now handled by robots even in Asia and are glued to a glass substrate as a preparation for cutting wafers.

This in turn makes wafer production attractive for producers of industrial robots. Only recently Kuka Systems in Augsburg, Germany acquired the relevant know-how from Czech machine builder Themis. With this move the plant manufacturer extends its product portfolio for photovoltaics to include various special dicing saws. Kuka intends to supply highly automated, turn-key wafer lines in future. So far the company had focused on module manufacturing and solutions for glass handling, string and or cross-soldering, placing strings on foil and glass, framing of modules as well as the subsequent quality tests. Describing the range Albert Vontz, Product Group Manager Solar Technologies at Kuka, says: “We can deliver module lines with up to 100% automation. And we are the only ones.”

Nevertheless, the Augsburg-based company will have to count on strong competition. Reis Robotics, for example, is a successful market player with its buckling arm robots and linear robot units. The company acquired its experience as a supplier of automotive manufacturing lines for autoglass, for instance. At Glasstec 2008, the leading international trade fair for the glass sector where companies also present solar applications, Reis exhibited a comprehensive product portfolio. Another strong player not only in automation technology for the photovoltaics industry is Manz Automation. Cooperating closely with machine builders Roth Rau, they provide their customers with systems and components for automation, quality assurance and laser process engineering. These suppliers will present their manufacturing technology solutions at Solarpeq – the Trade Fair for Solar Production Equipment held in Düsseldorf from 28 September to 1 October 2010. At the same time Glasstec is taking place, the leading international trade fair for the glass sector, at which more than 1,200 companies will be presenting their solutions in the areas of processing, lamination and automation technology, to name but a few.