Within the “FoXy” project, a Europe-wide consortium consisting of small and medium size enterprises, research institutes, and universities, intends to support the European goals for the Photovoltaic (PV) industry of decreasing module costs to € 1/Wp in 2010 and to have 3 GWp PV installed in 2010
Under the realistic assumption that Si-wafer based PV modules will dominate the market in the coming decade, the FoXy partnership will answer the need of the PV market for low price and high quality solar grade (SoG) Si feedstock by:
1. Further developing and optimising refining, purification, and crystallisation processes for metallurgical SoG-Si feedstock, as well as for recycled n-type electronic grade Si. 2. Optimising associated cell and module processes. 3. Setting input criteria for metallurgical and electronic n-type silicon to be used as raw materials for SoG-Si feedstock. 4. Transferring the technology from laboratory to industrial pilot tests.
Through the EU project collaboration, the FoXy consortium will develop a close partnership that has a high possibility to succeed in supplying new feedstock to the growing PV industry. The project structure is well prepared for development of methods for recycling of waste and end of life products. This is a new opportunity to enhance the competitive ability for the industry. In addition, the use of metallurgical silicon and recycled material in solar cells will most likely result in a shortening of the pay back time for PV modules with 6 months.
This lays a foundation for new investments in SoG-Si feedstock production and subsequent commercial use of the material produced.
Metallurgical grade Si, SoG-Si, and recycled material from new and unexploited sources, will be refined to acceptable purity through electrochemical, metallurgical, and physical methods under development. The refined SoG-Si material cost target is below € 15 per kg. Subsequent directional solidification and Czochralski crystal pulling will be optimised with respect to efficiency and yield. Advanced solar cell processing techniques will be developed on thin (200µm) large area (150x150mm2) wafers aiming at 17 % cell efficiency. Material and unit characterisation will be carried out at all stages of processing for the purpose of optimisation and in order to define standards for p- and n-type SoG feedstock.
