Efficient silicon recovery for circular solar power

The tech recovers silicon lost in PV manufacturing and extracts the element from spent panels

Spotted: Solar technology may be the future of energy, but the industry as it stands today has several sustainability issues of its own. These include inefficient production processes that mean valuable materials get wasted during panel manufacturing, and a lack of recycling infrastructure, which currently leads to 90 per cent of spent panels being sent to landfill. Startup ROSI is hoping to change this with innovative solutions for the recovery of ultra-pure silicon lost in the photovoltaic industry.

The manufacture of silicon wafers, which form the basis of PV cells, involves cutting a large silicon ‘ingot’ into very thin wafers, during which more than 40 per cent of the material is lost in the cutting fluid, in the form of silicon sludge or ‘kerf’ that’s typically discarded as waste. ROSI has developed processes to completely separate the fine silicon particles from the fluid, allowing the silicon to be cleaned of impurities and reused as ultrapure silicon granules in new silicon wafers, and the fluid to be used again to cut more silicon.

ROSI has also developed technology to recover ultra-pure silicon and silver from photovoltaic panels at the end of their life. The processes used are based on physical, thermal, and soft chemistry and do not use “aggressive chemistry,” meaning they are cost-effective.

At the end of last year, the company was included in the financing reserve of the European Investment Bank for an amount up to €22 million. The funding will be used to increase the capacity of its installations in France and expand its activities in Germany and Spain.

Finding more efficient ways to extract rare earth metals needed for clean technologies is the focus of several recent innovations spotted by Springwise, including the use of mining waste and a sustainable and efficient silicon recovery process.

Written By: Lisa Magloff