Zum, which provides student transportation including EV buses to 4,000 schools across the country, is partnering with the Oakland Unified School District to start selling power stored in EV batteries back to the California utility grid.

Oakland is the first school district in the U.S. to go fully electric with its buses, 74 in all, and will now be the first to test the concept of V2G (vehicle to grid) bidirectional charging. In effect, instead of the one-way charge into the vehicle, the school buses will be able to send their battery power back to the grid through Zum charging infrastructure.

Zum estimates that 2.1 gigawatt hours of energy can be sent from batteries back to the California grid annually. The company’s goal is to add 10,000 bidirectional EV school buses across the U.S. with 300 gigawatt hours of energy available to power grids each year. San Francisco Unified and Los Angeles Unified, much larger districts than Oakland, are expected to follow, Zum said. It also works with school districts in California, Colorado, Connecticut, Illinois, Maryland, Massachusetts, Missouri, Nebraska, Pennsylvania, Tennessee, Texas, Washington, Utah, and Virginia.


... HOW AND WHY?

The concept is considered a strong one given the fact that school buses are not in use during peak energy demand hours, for example, between 5 p.m. and 10 p.m. This allows the buses, and their owners, to execute an energy arbitrage trade: charging up for their core daily task of moving students when energy prices are lower, and feeding battery storage back onto the grid when utilities will pay more for it per kilowatt/hour. As owner of the buses in use in Oakland, Zum will be the one to receive revenue from the grid deal, but in other cases where school districts own the buses, they can generate revenue. In some cases, the revenue from power sales could be split.