“Electric bus fleets are ideal grid resources,” said Dana Guernsey, chief product officer and co-founder of Voltus, a technology provider partnering with Highland Electric Fleets and Montgomery County Public Schools in Maryland to manage the bidirectional flow of electricity associated with a fleet of electric buses.
Guernsey went on to point to the attention electric buses are getting in electric vehicle and energy management circles for their vehicle-to-grid (V2G) capabilities.
“What’s often overlooked though,” Guernsey added, “is their role in short-term grid balancing.”
Buses, and other EVs, can be used to help even out the delivery flow of electricity, which can sometimes be erratic when considering renewable energy sources like solar and wind.
“Since system peaks often occur during the hours when school buses are transporting kids home from school, it’s an even more perfect fit to think about what these bus fleets can do to support the balancing needs of the grid during the other hours of the day,” Guernsey said.
The Montgomery County school district began the process of transitioning many of its diesel buses to electric versions last year, through an agreement with Highland Electric Fleets, which will provide the buses and the charging infrastructure. The agreement is set up as a subscription service, which provides the buses at the same cost the district pays to purchase and operate its fleet of diesel buses.
The district is the largest in the state, serving more than 162,000 students and operates some 1,400 school buses. The first 25 buses have already arrived, said Gregory J. Salois, director of transportation for Montgomery County Public Schools. They are based out of a school bus depot already equipped with about 45 chargers, with other depots in the process of installing bus chargers.
“We will be getting 61 more buses by end of November, which will give us 86 total,” Salois added. Next year, another 120 e-buses will be added, with another 120 in 2024.
Voltus brings the software platform to the project, which allows the bus charging stations to connect to electricity markets, allowing the district to monetize the vehicles when they are not in operation.
“When there is an unexpected imbalance between supply and demand, most often caused by a power plant tripping offline unexpectedly or variability in supply from renewable energy resources, PJM [the regional transmission organization] will dispatch Voltus, typically for 10-30 minutes, until the grid emergency has passed,” Guernsey explained.
Maryland is not alone in using bus fleets to shore up grid demand. San Diego Gas & Electric and the Cajon Valley Union School District in southern California are involved in a similar pilot project. It’s part of a national move by the U.S. Department of Energy to explore vehicle-to-everything (V2X) technology.
There are about 480,000 school buses in operation in the United States, with fewer than 1 percent operating as battery-electric vehicles, according to market research by Environment America. A recent report by the firm MarkestsandMarkets anticipates the electric bus market in North America to be one of the most robust. Blue Bird, a major maker of school buses, delivered its 400th e-bus in March 2021, and expects to have 1,000 e-buses delivered in 2022.
