For the growth of the photovoltaic industry, it seems inevitable to create an independent feedstock supply with solar grade high-purity silicon, because the availability of the hitherto used by-products in the electronic silicon industry is limited and will not increase reasonably within the next 10-15 years. One of the results of the study "Present and likely future bottlenecks analysis for a sustainable photovoltaic policy" carried out by Bayer and Life, within EPIA, sponsored by the European Commission, within the ALTENER programme, shows that the feedstock used to date, based on electronic grade silicon Scraps is already limiting the PV market expansion even if a true shortage is not expected before 2004-2005 according to a "low growing PV market scenario". This conclusion implies that a new silicon feedstock not depending on electronic grade silicon production chain must be available on the market from the years 2004 to 2005. Bayer evaluated different ways for the production of solar grade silicon with a capacity of upto 5000 mt/yr. By calculating different routes, it seems possible to install a 5000 plant by an investment of 110 Mio. Euro, and to sell silicon feedstock with a price level of 12-15 Euro/kg. Bayer has been developing a suitable process and the new owner, the Deutsche Solar GmbH, is considering what effort is necessary for a pilot production plant. The feedstock situation is discussed under the aspect of availability of different materials and the efforts under consideration by different parties. (C) 2002 Elsevier Science B.V. All rights reserved.