Over the past years the worldwide production of PV modules has been considerably increased. During the last five years the growth rate averaged out at 40%. Growth rates of 13% per year are predicted until 2020 . Caused by the rising production volume problems of raw material supply for module fabrication become more important as well as problems of further utilization and disposal of end of use modules. Concerning the increasing amount of end of life modules an expansion from a few hundred tons at present up to several thousand tons per year is expected in the future. At present, end of use modules are mostly considered as industrial or municipal waste. Hence they were treated like glass or construction and demolition material. For this type of waste treatment a general recycling quota of 85% can be easily fulfilled by recycling the glass and metals from the modules. High value components like cells and wafers cannot be recovered by the means of these processes.

The predicted production growth rates involve an increasing demand of silicon and the PV industry estimates that a decreasing feedstock of silicon for solar cells production will make future business difficult. Since most of the end of use modules and rejects from module production contain undamaged cells, several research institutes and companies are working on recycling concepts, which allow to recover the undamaged cells and wafers from modules for reusing. A recycling solution for all types of modules was established at Deutsche Solar AG. Running on a pilot plant scale the process of Deutsche Solar AG enables to recover silicon wafers from crystalline modules, which can be reprocessed to solar cells afterwards and used in modules again. Besides economic efficiency environment – friendliness and process reliability are playing an important role. Thus in the recent time process optimization, the possibilities of further improvement of process reliability and ecological considerations are in the focus of the interest. In this paper some examples of these activities are given.

The recycling process of Deutsche Solar AG consists of two main steps. First the laminate is burned off to facilitate the manual separation. In case of crystalline silicon cells, the metallization, antireflective coating and pnjunction are removed subsequently by etching. Solar cell recycling can be done by etching on a technical scale, the surface finish can frequently be adjusted to the customer’s demands.

http://www.ipcrystalclear.info/data/pdf/SP6%20Paper%20for%20EUPVSEC20%20(DS,%20Bombach-Wambach).pdf