The corrugated medium and linerboard board are made of kraft containerboard, a paperboard material usually over 0.01 inches (0.25 mm) thick.
The panels contain cells made in China, Taiwan and, sometimes, Germany. Grape still plans to import inexpensive Chinese-made cells, and to buy Oregon-made inverters -- which convert direct current to alternating current -- for the panels it assembles in Eugene.
A SolarCity employee carries a solar panel being installed on the roof of a home in the Eagle Rock neighborhood of Los Angeles, Calif. in May 2014. Photograph by Patrick T. Fallon â Bloomberg/Getty Images.