These Electric School Buses Moonlight as Batteries for the Power Grid
A school bus keeps strange hours. It works a hard hour or two in the morning, idles in a lot through the school day, goes out again for the afternoon run, then sits parked all night. For most of any given day, it does nothing at all.
Cherry Creek School District, just outside Denver, looked at all that idle time and saw an opportunity to put them to good use. Six new electric buses in the district now pull double duty as backup power for the local grid. Each one carries a large battery, and each is wired for bidirectional charging, the kind that lets electricity flow both directions. The buses can draw power in to charge themselves, and they can send power back out. As the Colorado Sun reported, the fleet doubles as backup batteries for the grid around it.
The schedule happens to suit a battery well. The buses fill up overnight, when power is cheapest and the grid is quietest, then head out on the morning and afternoon runs. By early evening, when a whole neighborhood’s air conditioners and stoves come on at once and demand spikes, the buses still have charge to spare, and they push some of it back onto the grid to help cover that peak.
The money behind it came from a utility. Xcel Energy put up a $2.4 million rebate through its bus electrification program and signed on as the grid partner. The depot upgrades that make the two-way charging possible arrived at no upfront cost to the district. The buses themselves carry a lease. Highland Electric Fleets manages the fleet.
Highland has put numbers on the potential. By its estimate, 25 buses configured this way could power about 116 homes for a day, and roughly 275 of them could cover some 1,400.
The district broke ground on a new bus depot in early June. Jennifer Perry, Cherry Creek’s interim superintendent, laid out the appeal at the groundbreaking: “This partnership works to support our environmental goals while delivering long-term operational savings.”
Six buses will not hold up a city, and Cherry Creek is upfront about that. The fleet is a demonstration, a proof of concept more than a power source. What makes the idea worth watching is that it rides on something already underway. Electric school-bus fleets are multiplying across the country, and every one of those buses spends most of the day parked and charged. That adds up to a lot of batteries with time on their hands.
The buses were bought to carry kids to school. The rest of what they do, they do while waiting for the afternoon bell.
