California's Mount Diablo Unified School District now has 12.1 megawatts (MW) of solar on the rooftops of 51 schools.
This is the biggest solar system installed for a school district in the world.
SunPower's solar systems are expected to save the district $3 million a year - 92% of all electricity costs. Over 30 years, that adds up to $220 million that's freed up for education.
The District, in the San Francisco Bay area, serves 33,000 students. Most of the work was done during school hours and still was completed in 15 months.
Del Monte Electric installed the systems, including underground electrical distribution, solar installation and connecting to the utility. Over 28,000 PV panels and 150 miles of wire are installed on carports and rooftops throughout the campuses.
"This was a very complex project and we had to manage a huge crew of sub-contractors to work under aggressive schedules to minimize impact to the school district," says John Hunter, president of Del Monte Electric.
Del Monte Electric managed a construction crew of over 100 people and trained the workforce on solar installation. Three underground crews worked on boring, drilling, and excavating at multiple sites.
Voter-approved Clean Renewable Energy Bonds (CREBS) funded the $56 million project, along with general obligation bonds.
In this case, the District owns the solar systems, in other cases, such as the Murrieta Valley Unified School District in Southern California, they are using SolarCity's leasing model.
As of 2011, Ohio led the country in the number of schools adding solar, and scores of school districts are doing it.
The size pales in comparison to Mount Diablo, but significant solar systems are in Boulder, Colorado with 1.4 MW, Oak Grove School District near San Jose, California, with 1.8 MW, and 10 catholic schools in New Jersey, with 1.5 MW. South San Francisco's Unified School District has 1.7 MW.
Until now, Silicon Valley's East Side Union High School District had the biggest in the country at 7.1 MW.
Read, Making the Grade with Clean Energy, describes 200 solar projects at schools across California: