DECKER Anlagenbau receives Intersolar AWARD 2011

DECKER received the award in the PV Production Engineering category during the Innovation Exchange at Intersolar Europe in Munich for its trendsetting silicon granulate etching system. The forward thinkers in the solar energy sector are discussing the topic of module recycling intensively due to the impressive growth of the solar energy industry. And the cost-efficient cleaning of solar silicon plays an integral part. DECKER solves this problem using a unique belt filter which integrates the silicon cleaning smoothly into the production process. The medium-sized company with its headquarters in the Bavarian town of Berching convinced the Jury with the new possibilities which result from this system for recycling of silicon. Managing Director Kay Rehberg accepted the award on Wednesday.

Every year, independent representatives from research, science, industry and trade press award the "Intersolar Award" to outstanding and trendsetting innovations from national and international companies and institutions within the solar energy sector.

Valuable scrap accrues in different stages of the production process when manufacturing solar cells; this scrap can be reused if the right recycling technology is utilized. This will become increasingly important due to growing production numbers as well as rising spot prices. A further market segment is also the recycling of old solar plants which promises to be an area with rapid growth for the future. However, the cleaning of small parts or of granulate is a tremendous technical challenge for the solar energy sector due to the large surface area and the required degree of cleanness. DECKER Anlagenbau GmbH has developed a groundbreaking solution for these problems: An innovative etching system enabling the cost-efficient integration of silicone cleaning into the production line.

DECKER-belt filter: High throughput at low costs

For this reason, DECKER has moved the cleaning process to a conveyor belt. DECKER's belt filter is unique, saving up to 50% in cost as well as time and protects the environment. Cleaning the production scrap in large-scale production settings is only possible with this technology. Standard cleaning methods are reaching their limits in this setting since they drastically reduce the production throughput. In comparison, the typical scale for the throughput of a DECKER-belt filter is about 1,000 tons per year. The DECKER-belt filters are the ideal alternative to existing cleaning methods, which use standard product carriers such as barrels or baskets. Quality problems, in addition to time and cost factors, are inherent to the system since the etching processes take longer inside the baskets than they do on the surface. Costs for the DECKER-belt filters depend on different parameters; return on investment within one year can be realised in certain conditions.

Fast cleaning down to the ppbw zone.

Cleaning silicon surfaces is a complex matter. There a many different possible contaminations, ranging from finger prints to metallic residues which arise during the milling and transport processes. Cleaning the relatively large surface becomes a challenge for grain sizes ranging from 100 micrometers and four millimeters. DECKER-belt filters completely remove all contamination to the required level which is within the ppbw zone (ppbw = parts per billion by weight). At the moment, the required average surface quality for high quality polysilicon granulate is at a value of less than 15 ppbw for metals such as iron. Metal contamination reduces the efficiency of solar cells. The efficiency of solar cells is mainly determined by the cleanness of the silicon. The market increasingly demands a silicon granulate with a high degree of surface cleanness. Valuable solar silicon is accrued as waste or scrap in different forms (powder, granulate, lumps, wafer) during the production of solar wafers in almost every single step during the production process. This can be reused in the production of silicon ingots. DECKER's silicon granulate etching system enables manufacturers to recycle solar silicon quickly and cost-efficiently.