How To Print 3000km Of Solar Cells A Year

You're looking at the Applied Bacini Pegaso -- one of the most productive solar cell printing lines on the planet -- fabricating electrical circuits on both sides of a solar cell. And by productive, I mean 20 million cells a year, enough to power 10,000 typical US homes.

Two cassettes -- each holding 40 Photovoltaic wafers -- are loaded into the system every 100 seconds. The Pegaso's wafer-handling mechanism moves wafers between two independent conveyor tracks to optimise output -- it can finish a solar cell every 1.2 seconds when running at maximum capacity -- where they travel to the screen printer.

There, dual print heads force conductive silver paste through special screens to create micron-level contact lines on the wafer. These print heads can adjust printing parameters "on-the-fly" between wafers. Once they pass an initial wave of inspection, the wafers are flash baked to dry and slightly harden the contact lines before being shuttled to a higher temperature furnace that then fires the metal into the silicon.

After they've cooled, they then undergo a second round of inspections and testing—first through an optical scanner to ensure the contact lines are accurate, then through an IV tester to confirm the power output. The solar cells are then sorted by their level of efficiency in the IV test and packaged for distribution.