One of Xunlight's portable thin film solar panels. Photo: Xunlight
You've probably seen solar panels that roll-up for easy storage; a number are available to charge batteries and personal electronic devices. But a new manufacturing process from Xunlight takes the idea to a whole new level... Manufacturing roll-up thin film solar panels on stainless steel plates 3 feet wide and up to a mile long. This is how Xunlight describes the process:
Xunlight’s roll-to-roll manufacturing process allows the company to produce triple-junction thin-film silicon solar cells on rolls of thin stainless steel substrates, three feet wide and up to one mile long. The long stainless steel web is guided through a series of vacuum chambers for the deposition of nine semiconductor layers using a plasma enhanced chemical vapor deposition process, and back-reflector and top electrode layers using a sputtering process. The combined thickness of the layers for the triple-junction solar cell is approximately one hundredth of the thickness of a typical sheet of paper. Therefore, only a small amount of silicon is used.
OK, so you won't be able to get a whole mile long solar panel, nor would probably want one. Xunlight says it produced 3'x5' and 3'x18' flexible steel panels so far.
The catch in all this? While conventional solar panels have efficiencies topping 20%, Xunlight's panels are only are about 8% efficient. Technology Review gives the example of one of Xunlight's 18' long panels producing 330w, whereas if that same area was covered in conventional crystalline silicon panels in would be 740w.
Quite a difference, but then again, these panels could be used in applications where conventional solar panels simply wouldn't be appropriate.
More: Xunlight (press release)