Peaker on wheels: Electric school bus delivers power to grid for 50 hours over summer

An electric school bus in the US state of Massachusetts, equipped with a battery from American automotive and energy storage company Proterra, successfully delivered power back to the grid for over 50 hours over the course of the summer.

Marking the first time that an electric school bus has been leveraged as an energy resource by the local utility National Grid, it marks one of the first instances in the US where an electric school bus has supported the grid in this way.

The Thomas Built Buses Saf-T-Liner C2 Jouley electric school bus discharged nearly 3MWh of electricity back into the grid over the course of 30 separate instances.

“By delivering stored clean energy back to the grid when it’s needed most, electric school buses can help create a more resilient local power system and reduce the dependence on expensive fossil fuel power plants,” said Gareth Joyce, the president of Proterra.

“Switching to zero-emission, electric school buses signals a transformational shift towards clean transportation and clean energy to help protect the health of our children and the communities they live in.”

The summer means most buses are sitting idle as schools are on break, so a fleet of electric school buses can provide a potentially vital extra grid resource to meet times of increased demand.

Even during school weeks, the average US school bus transports students for approximately six hours a day, only 200 days a year, and are otherwise parked or idled when not in operation.

The buses run by the Beverly Public Schools District are provided by Highland Electric Fleets, along with chargers and the electricity needed to charge the buses under a mileage-based subscription.

Highland worked with National Grid to ensure that the Beverly bus site was prepared for energy discharge and coordinated participation in National Grid’s Connected Solutions Daily Dispatch program.

By sending electricity back to the grid when demand for electricity was at its highest and most expensive – having been able to charge when demand was low, and electricity was cheaper – the Beverly Public Schools buses helped to reduce local emissions and reduced the need to fire up costly fossil fuel “peaker” plants.

National Grid also compensates participants in its Connected Solutions Daily Dispatch program, further incentivising the use of distributed energy resources.

“This underlines the strength of the technology neutral approach of the Connected Solutions Daily Dispatch program,” said John Isberg, head of customer sales and solutions at National Grid.

“Through this single program we have enrolled batteries, fuel cells, thermal storage, V2G, and many other technologies without needing to confuse customers and vendors with separate programs and incentives for each technology.”