An electric school bus in Beverly, Massachusetts, successfully delivered power back to the electricity grid for more than 50 hours over the course of the summer using vehicle-to-grid (V2G) technology. This is the first time an electric school bus has been leveraged as an energy resource by the regional utility National Grid in New England and among the first instances in the United States that an electric school bus has supported the electric grid in this way.

In conjunction with Highland Electric Fleets and National Grid, a Thomas Built Buses Saf-T-Liner C2 Jouley electric school bus equipped with a 226 kWh Proterra Powered battery system discharged nearly three megawatt-hours of electricity stored in the bus to the regional electric grid over the course of 30 events this summer.

Highland, who provides the bus, chargers, and all electricity to Beverly Public Schools under a mileage-based subscription, worked with National Grid to ensure that the site was prepared for energy discharge and coordinated participation in their Connected Solutions Daily Dispatch program. Under this program, National Grid utilized the energy stored in the electric school bus battery on 30 different occasions over the summer to lower demand on the grid during times of peak demand.

Thomas Built’s Saf-T-Liner C2 Jouley with Proterra’s bidirectional charging system managed the charging and discharging of the electric school bus back into the grid.

Image source: Thomas Built Buses

By sending electricity back to the grid when demand for electricity was at its highest and most expensive, the school bus helped reduce local emissions and decreased the need to fire up fossil fuel peaker plants. National Grid compensates participants in this program for their energy services, incentivizing the use of distributed energy resources to strengthen the local grid.

Participation in National Grid’s program marks an important step in closing the up-front cost gap between traditional diesel school buses and electric school buses, as revenue from vehicle-to-grid (V2G) programs offer a unique means to improve the economics of electric school bus ownership.

The average school bus transports students for approximately six hours a day, 200 days annually, and are otherwise parked or idled when not in operation. This is particularly true during summer months, when demand for electricity is often at its highest and clean energy stored in idled electric school buses can provide an energy resource to the grid.

In Beverly, Highland provided a turnkey, fixed-price subscription that eliminated up front cost, risk, and complexity of managing the electric school bus, and allowed Beverley to benefit from the V2G services provided by the bus through a lower subscription price. This type of public-private partnerships allows school districts to capture the value of a V2G program and fully unleash the potential of electric school buses.

The Saf-T-Liner C2 Jouley couples the 226 kWh of total energy capacity from Proterra’s battery with a Proterra electric drivetrain to offer up to 135 miles of drive range to meet the needs of school bus fleets.