The Poway (Calif.) Unified School District has installed solar power systems on the roofs of portable classroom buildings at 14 campuses.

Financed through a power purchase agreement with no out-of-pocket costs to the district, the project is expected to reduce Poway's electricity expenses by nearly 15 percent and save the district $250,000 per year, according to Alta Energy, the company that installed the panels.

Photovoltaic panels have been installed on 65 of the district's standard 24 by 40 feet relocatable, portable classrooms. 

Placing the panels on these buildings enables the use of standardized designs that are quicker, less expensive and less disruptive to install than more conventional designs such as solar parking canopies.

California public schools spend about $700 million per year on energy. By installing relatively small solar power systems that generate only 10 to 20 percent of their total electricity consumption, schools can switch to solar-friendly rates that often provide significant energy bill reductions, Alta Energy says.