Electric School Buses Power 1,000 Homes and Generate Revenue in California

A fleet of 74 electric school buses in Oakland, California, has spent the last two years powering approximately 1,000 homes while generating revenue through vehicle-to-grid (V2G) technology. The project, operated by Zum and utilizing chargers built by Tellus Power, demonstrates how fleet vehicles can serve as reliable grid resources during peak demand periods.

What Happened

Tellus Power, a charging equipment manufacturer based in Irvine, California, installed V2G chargers for the Oakland Unified School District to enable bidirectional energy flow. The 74-bus fleet holds a total of 11.5MWh of energy storage. According to the source, the buses charge overnight and use about 20-40% of their capacity during school hours. After the school day ends, the buses plug into the V2G chargers and discharge energy back to the grid, aligning with the late afternoon peak in electricity demand when residential usage spikes due to air conditioning and cooking.

The fleet can discharge at approximately 2 Megawatts simultaneously. Given that the average home uses about 2 kilowatts in the evening, the collective output is sufficient to power around 1,000 homes. Over the past two years, the buses have returned 1.7GWh of energy to the grid with over 99.5% uptime. The chargers are assembled in America and are "Build America Buy America" compliant. Tellus Power, which has been manufacturing AC and DC chargers since 2010, states that its V2G units do not require large transformers on-site, facilitating faster and less expensive deployment compared to traditional power plant connections.

Why It Matters

This project highlights the economic viability of V2G technology for fleet operators, offering a model for generating revenue through energy arbitrage. By buying power when it is cheap and selling it back to the grid when demand and prices are high, the Oakland school district has reportedly earned hundreds of thousands of dollars in electricity sales. This revenue stream helps offset the costs of electrifying the fleet, a significant consideration as fuel prices remain high.

The success in Oakland has spurred additional projects across North America. Tellus Power is currently deploying or has deployed V2G systems for four school buses in Burlington, Vermont; two city bus chargers for Lynch Bus Lines in Burnaby, British Columbia; a pilot program at three school district sites for ComEd in Illinois; and a larger fleet of 104 school buses in San Francisco, which is expected to scale to 238 vehicles. The company notes that V2G capacity can be brought online in months, significantly faster than the years required to build and connect traditional power plants to the grid. While consumer EVs face barriers such as costly home equipment and limited V2G compatibility, fleet locations allow for the aggregation of large battery capacities in a single project, simplifying implementation.

The Bottom Line

Electric school buses in Oakland have proven that V2G technology can reliably support the grid and generate substantial revenue for fleet operators. With 1.7GWh returned to the grid over two years and expansion plans in multiple states and Canada, the model demonstrates how municipal vehicles can act as distributed energy resources. Tellus Power is now looking to expand this application to other municipal vehicles, such as electric garbage trucks, which share similar duty cycles and grid service potential.