Sonoma State University powers on solar carports and battery storage

Sonoma State University in California has switched on a large solar and battery system, built by TotalEnergies. The setup includes solar carports over five campus parking lots and a battery storage system, together generating 4.1 megawatts of solar power and 1.55 megawatt-hours of battery storage. It's expected to produce more than 7.9 million kilowatt-hours of electricity in its first year, while the carports also give parked cars shade and cover.

The battery system is designed to work as a "microgrid," meaning it can disconnect from the main power grid during Public Safety Power Shutoffs, the planned outages California utilities use during wildfire risk periods. That keeps critical campus buildings running when the surrounding grid goes dark. The university expects the batteries to save more than $5 million in utility costs over the first five years, money that will go into a fund supporting student programs and research.

The university paid nothing upfront. TotalEnergies financed, built, and now maintains the system under a power purchase agreement, a contract where the campus buys the electricity generated at a rate lower than what the local utility charges, while the company handles upkeep. This isn't directly relevant to a homeowner's own roof, but it shows the same basic deal — solar plus battery storage with no upfront cost, paid back through cheaper electricity — showing up at larger scale on institutional buildings, and it points to battery backup becoming more common in areas with utility shutoff risk.