A three-year electric school bus project in New York state that concluded this month offers insights on how to best support vehicle-to-grid projects (V2G).
Five electric school buses were used to transport elementary students in White Plains to school each day. The batteries on the buses were charged and discharged at a depot in North White Plains operated by National Express. Three of the buses were retrofitted with power converters, which allowed them to perform V2G bi-directional charging. When the buses plugged in after transporting students, the chargers allowed utility Con Edison to reverse the flow of the power back into the grid.
“Our study yielded rich information about the potential to deploy e-school buses on a large scale to discharge power into the grid at times when our customers need it most,” stated Leonard Singh, Con Edison’s senior vice president of customer energy solutions. “While we have challenges to overcome, the coming electrification of school buses in New York state could hold benefits for school districts, transportation providers and our customers.”
Con Edison, one of the largest investor-owned energy company in the U.S., conducted the study in partnership with bus manufacturer Lion Electric Company, Durham parent company National Express, project developer First Priority Group Electrified (FPGe), and energy technology company Nuvve Holding Corp. The objective was to determine the technical and economic viability of using school buses with V2G capabilities to support the grid when the demand for power was high.
The study reported that the buses met the goal of achieving an average of 1.4kw hours per mile. The school buses also exceeded the goal of minimal electricity losses, in which 85 percent of the power in the batteries reached the grid. A press release noted that moving electricity through conductors always results in some loss.
“The research showed that using the batteries for both transportation and grid support causes the batteries to degrade just like driving would,” the release adds. “That means that future V2G may require extended warranties or earlier battery replacements.”
Among the other findings, drivers and student riders indicated they were pleased with vehicle performance and bus availability. Additionally, using school buses to support the grid is beneficial to Con Edison customers, as it uses power supplied by the vehicle batteries to reduce stress on electric-delivery equipment and keeps consumer costs lower. However, challenges do remain, such as the upfront costs of purchasing electric school buses. “But mass production and other advances could change the cost equation in favor of e-buses,” the release adds.
“As one of the largest school bus operators in North America, National Express was elated and honored to host the V2G project,” commented Carina Noble, the company’s senior vice president of communications and external affairs. “While there were reliability difficulties with some components initially, the successful discharges proved that V2G technology in a fixed-route service is viable for grid support. Providing a zero-emission riding experience is part of our sustainability roadmap and proving our technologies will get us to our destinations safely and on time.”
Edward Flavin, the vice president of external communications for National Express, told School Transportation News that as with any study, it took time to eliminate hiccups that occurred at the project start. “Early on in the study, there were some issues with the hardware that we learned required some energy throttling to increase reliability,” he noted.
Flavin added that the company will not be continuing with V2G at its White Plains location because there was no interconnection agreement in place when the project was completed.
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Gregory Poilasne, chairman and chief executive of Nuvve, added that the project has helped policymakers, school districts, and utilities begin to understand how V2G using DC fast-charging stations can benefit the electrification ecosystem by creating cleaner rides for students.
Marc-Andre Page, vice president of commercial operations at Lion Electric, said V2G can help balance grids in the future as well as lower the total cost of ownership of electric school buses, “allowing them to invest those funds back into education and their organizations,” he said.
Electric school buses in New York are only ramping up. New York City recently passed a law requiring all school buses to be electric by 2035, and Gov. Kathy Hochul has made the same commitment for the state. The state’s fiscal 2023 budget calls for all new school buses purchased by 2027 to be zero-emissions and all school buses operating across the state to be zero-emissions by 2035. The budget is reportedly providing $500 million to support school districts purchasing these zero-emission school buses and charging infrastructure.