Zūm Says San Francisco’s Electric School Bus Rollout Has Started — Its Update Doesn’t Say How Many Are in Service

Zūm says San Francisco Unified School District’s electric-school-bus rollout has begun.¹ The company said Sept. 3 that the first buses are now being deployed, more will phase in through the fall as they arrive from the manufacturer, and charging and supporting infrastructure is fully in place.¹

What Zūm’s update does not say is how many electric buses are currently in service.¹ The 104-bus figure associated with the project comes from Zūm’s May announcement, which described 104 electric school buses with bidirectional charging infrastructure as the planned first phase — not as a current operating count.²

SFUSD’s own transportation page independently confirms that the district currently contracts with Zum Services Inc. for student transportation, but it does not provide a September electric-fleet count or V2G operating status.³

The 104-bus figure is still a project baseline

Zūm’s May plan called for the first 104 electric buses to be followed by an expansion to 238 electric buses by the 2027-2028 school year.² The Sept. 3 update says additional buses will be phased in through fall as they are provided by the manufacturer, but it does not say the first 104 have all arrived, entered service or been assigned to routes.¹²

That distinction matters because the September development is an execution milestone, not a new fleet-size announcement. The public evidence supports saying the project has moved from a planned deployment into a company-reported rollout.¹² It does not support treating 104 as the number of buses currently operating.¹²

Bidirectional capability is not the same as active V2G

The project’s grid story is also narrower than the original plan might suggest. In May, Zūm said the planned 104-bus first phase would use bidirectional charging infrastructure and would have the capability to return approximately 3 GWh of energy to the local grid annually during peak periods.² That figure is a company-stated capability and projection, not a measurement of electricity already exported by SFUSD buses.²

The research packet’s Sept. 6 review of current public sources did not establish that the San Francisco fleet is already exporting energy to the grid.¹²³⁴⁵ The reviewed material did not identify an SFUSD-specific live grid-export program, dispatch event, measured exported energy, charger count or interconnection capacity.¹²³⁴⁵

That does not mean V2G is absent or will not operate. It means the public evidence reviewed so far establishes bidirectional-capable project design and installed supporting infrastructure, not demonstrated San Francisco grid dispatch.¹²⁴⁵

PG&E’s descriptions of separate school-bus V2G projects show the difference. In Oakland, PG&E publicly documented 74 bidirectional chargers, utility upgrades and 2.7 MW of capacity for Zūm’s deployment.⁴ In Fremont, PG&E separately described bidirectional chargers, grid upgrades and enrollment in the Emergency Load Reduction Program.⁵ Those facts apply to Oakland and Fremont, not SFUSD, but they illustrate the additional operational details that can accompany a publicly documented V2G deployment.

For San Francisco, the next meaningful milestones are more concrete than another capability claim: a quantified in-service electric-bus count, SFUSD- or PG&E-specific charger/interconnection details, enrollment in a named grid-services program, or measured bus-to-grid discharge. Until then, Zūm’s Sept. 3 announcement establishes that the rollout has started and the supporting infrastructure is in place — not that all 104 planned first-phase buses are running or that the fleet is already sending power back to the grid.¹²³⁴⁵

Sources

Footnotes

1. Zum Begins Historic Electric School Bus Rollout in San Francisco — Zūm, Sept. 3, 2026; observed Sept. 6, 2026. https://www.ridezum.com/press-release/zum-begins-historic-electric-school-bus-rollout-in-san-francisco/ Establishes Zūm’s statement that the SFUSD rollout has begun, the first buses are being deployed, more will phase in through fall, and charging/supporting infrastructure is fully in place. It does not state a current bus count or establish actual grid export. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

2. Zum and SFUSD Announce Largest Electric School Bus Deployment in the Nation — Zūm, May 21, 2026; observed Sept. 6, 2026. https://www.ridezum.com/press-release/zum-and-sfusd-announce-largest-electric-school-bus-deployment-in-the-nation/ Establishes the May project baseline of 104 first-phase electric buses with bidirectional charging infrastructure, the later 238-bus plan, and Zūm’s approximately 3 GWh/year grid-return capability statement. Those are company plans/capability claims, not proof of current fleet count or realized export. ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

3. Transportation — San Francisco Unified School District, current service page; observed Sept. 6, 2026. https://www.sfusd.edu/transportation Establishes that SFUSD currently contracts with Zum Services Inc. for student transportation. It does not establish the electric fleet count, charger configuration or V2G operating status. ↩ ↩² ↩³ ↩⁴

4. PG&E Helps Zum Deploy Nation’s First 100% Electric School Bus Fleet in Oakland for New School Year — PG&E, Aug. 27, 2024; observed Sept. 6, 2026. https://www.pge.com/en/newsroom/currents/future-of-energy/articles-4040-pge-helps-zum-deploy-nations-100-electric-school-bus-fleet-oakland-new-school-year.html Establishes separate Oakland-project details including 74 bidirectional chargers, utility upgrades and 2.7 MW capacity. It does not establish any SFUSD project detail. ↩ ↩² ↩³ ↩⁴ ↩⁵

5. In Fremont, PG&E Helps Launch Another Vehicle-to-Grid Electric School Bus Fleet — PG&E, Aug. 11, 2025; observed Sept. 6, 2026. https://www.pge.com/en/newsroom/currents/future-of-energy/in-fremont--pg-e-helps-launch-another-vehicle-to-grid-electric-s.html Establishes separate Fremont-project evidence including bidirectional chargers, grid upgrades and Emergency Load Reduction Program enrollment. It does not establish any SFUSD project detail. ↩ ↩² ↩³ ↩⁴ ↩⁵