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.
The largest solar plant in the United States is officially fully operational. The Topaz Solar project in San Luis Obispo County, California completed its final 40-megawatt phase last month, making it the first 500-plus megawatt farm in the country.