Denver Public Schools Runs 28 Electric Buses on a 650 kW Depot With 26 Plugs
- EVs Fleet & Depot Charging News
Marin Holt
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- 7 minutes read
- Total charging capacity: 650 kW
- Charging plugs: 26
- Electric buses served: 28
- Dispensers: 13 dual-port Kempower Satellite
Denver Public Schools opened a 26-plug charging hub at its Hilltop Bus Terminal in Denver, Colorado, five days before the district’s first day of school on August 24, 2026. The terminal runs 28 battery-electric buses on a Kempower distributed charging system rated at 650 kilowatts total. Electrical contractor Winn-Marion led the installation. The district added 25 Blue Bird Vision electric buses to the three it already ran, which makes it the largest electric school bus fleet in Colorado.
The hub uses 13 dual-port Kempower Satellite dispensers. Each dispenser feeds two plugs, so 26 buses can sit connected at once. PowerFlex, formerly The Mobility House, manages smart charging and energy use at the site.
The depot is deliberately undersized
Divide 650 kW across 26 plugs and each plug averages 25 kW. That is well under what a single DC fast charger delivers to a transit bus. The district did not buy 26 full-power chargers. It bought one power block and split it.
This is the point of a distributed architecture. The Kempower system moves available power to the vehicles that need it and starves the ones that are already full. A school bus depot is the easiest possible case for that trick. Buses return by mid-afternoon, sit through the night, and leave on a fixed morning schedule. The dwell time is long and it is predictable.
Why It Matters
The alternative design would have forced a much larger service upgrade. Twenty-six chargers at 60 kW each would need roughly 1.6 MW at the meter. Denver Public Schools instead energized a 650 kW service, which is about 40 percent of that. The utility interconnection is smaller, the transformer is smaller, and the demand charge is set by a lower peak.
Fleet operators reading this should note what the design costs them. A 650 kW service cannot recharge 28 buses quickly. It recharges them overnight. Any route change that brings buses back needing a fast midday top-up will run into the power ceiling, not the plug count. Depots that later add routes, or swap to buses with larger packs, have to revisit the service size even though every plug is still there.
School districts are the segment where this math works best. Transit and freight depots have shorter dwell windows and less forgiving schedules, so they cannot cut the service down this far. The Denver result is a real saving, but it is not a template that transfers to every fleet.
Critical Perspective
Denver Public Schools bought 26 plugs but only 650 kW to feed them, which is about 23 kW per bus if the whole fleet plugs in at once. Houston Metro sized its own depot at 12 MW for 200 buses, roughly 60 kW each, because transit duty cycles do not leave an eight-hour overnight window. The bet in Denver is that the school schedule never changes, and the Zum program at San Francisco Unified School District is already fitting bidirectional hardware on 238 buses that assumes the opposite, that buses will be asked to move power on the utility’s clock rather than the district’s. What happens to the 650 kW ceiling the first year a route runs late or the district wins a vehicle-to-grid contract?
Sources
- Kempower: Denver Public Schools, Winn-Marion deploy Kempower solutions for growing electric bus fleet
- electrive: Kempower equips Denver schoolbus depot for 28 electric buses
- Electrek: Colorado’s largest electric school bus fleet gets a 26-plug charging hub
- Charged EVs: Denver Public Schools adds 25 electric school buses to its fleet
- KDVR: Denver Public Schools has 25 new electric buses just ahead of the school year
