Although silicon is one of the most abundant elements on earth, single crystal silicon wafers don't grow on trees- yet. It is actually quite an extensive and expensive process to produce silicon wafers, which are used to create everything from computer chips to solar cells. As announced via the IBM video above, IBM'ers in Vermont have devised a process that allows their rejected wafers to be repurposed for solar cells.
From what I can glean, the process involves water and gentle scrubbing to remove the microstructures on the surface of the wafer. The removal of these features is key to recycling the wafer, as the bits scrubbed off represent important intellectual property (IP) for the company. By removing the sensitive information, the wafer can be saved from being crushed into dust, and used by other companies.IBM has said it will license the technology to other manufactures, and could result in around 3 million wafers repurposed per year. A nice bonus for the solar cell companies that use these silicon wafers as a core to their technology. Also a nice bonus for IBM, who has a waiting customer for what would normally be a waste product.
Feeding on the waste stream of the computer chip manufacturers has nursed the solar industry along for several decades. I'm glad IBM is helping to enrich the milk a bit, and the IBM'ers in Vermont certainly deserve a hand for their ingenuity. Pragmatic steps like this can slowly and effectively change our system towards sustainable goals.
However, I can't help but wonder where the silicon microstructure sludge produced in the process ends up, and haven't found anything regarding the waste stream process itself. Any IBM insiders out there should feel free to enlighten us on this point.
I would also like to see the solar industry find its own feet without the need for single crystal silicon, and move to a more sustainable feedstock. After all, how often does IBM make this kind of a mistake? (Answer: 3.3% in this case)