ALTONA, Australia—Toyota has installed a 500-kilowatt photovoltaic system on the roof of its assembly plant here. The 2,000-panel system will provide approximately 10 percent of the factory’s energy needs.

CHATTANOOGA, TN—Volkswagen’s assembly plant here is now getting as much as 9.5 megawatts of electricity from a massive solar panel installation.

FREMONT, CA—Silevo Inc. has created a new solar cell that is more than 21 percent efficient converting sunlight into electricity.

NORTH CHARLESTON, SC—Boeing’s new assembly plant here is getting much of its power from a 2.6-megawatt solar panel array on its roof. The largest rooftop solar installation in the Southeast, the array generates enough power for 250 homes.

LOS ALAMOS, NM—Thin-film solar cells could be made far more efficient with the addition of bundles of carbon nanotubes, according to researchers at Los Alamos National Laboratory.