Power wheels
How the batteries in electric school buses are easing stress on the grid
Buses in Oakland Unified School District's vehicle-to-grid electric school bus fleet in Oakland, Calif.
UTILITIES
Schools are out for the summer, but the batteries in more than 200 electric school buses are helping some people find relief when temperatures soar.
From California to North Carolina, yellow electric school buses are sending power back to the grid, easing some strain when demand spikes during heat waves. Hundreds more buses are expected to come online.
The stored energy from school buses and other electric vehicles is dwarfed by power plants. But efforts to use their batteries to return power to electrical systems, known as Vehicle-to-Grid, or 1/2G, show how EVs could fortify strained power grids.
Fully deployed 1/2G projects involving about 230 of the nation's roughly 6,700 electric school buses now have the capacity to supply about 8 megawatt-hours of power at a given time, according to the World Resources Institute's Electric School Bus Initiative.
By contrast, PJM, the largest U.S. regional grid, needs more than 160,000 megawatts of power to meet peak demand for 67 million people during major heat waves.
"It's very early days. School buses will be a critically important backbone of 1/2G capacity," said Steve Letendre, senior adviser to the Vehicle Grid Integration Council trade association.
Electric school buses have large batteries, some exceeding 200 kilowatt-hours. They can charge when demand is low and send power back to the utility. They often are idle in the summer, when electricity demand surges.
At least 31 utilities and 21 U.S. states are involved in 1/2G school bus projects, WRI said.
The number of electric school buses on the road should more than double to around 14,625, or 3% of the total fleet, in the coming years, WRI data showed. Many of those will be 1/2G-enabled.
Still, capacity from 1/2G electric school bus projects needs to grow exponentially to make a meaningful difference.
Consulting firm ICF forecasts 445,000 megawatts of U.S. grid capacity additions through 2030, partly driven by the data center boom.
Technology faces multiple barriers
1/2G projects face hurdles including up-front costs and a lack of universal 1/2G technology. Regulatory frameworks and standards are years away. Electric-vehicle owners and operators face concerns that repeated charging and discharging of a battery could accelerate battery degradation, and that use of 1/2G could void a battery warranty.
Electric buses do not spew tailpipe pollution, but critics of vehicle electrification and government/public investment in alternative energy projects argue they could tax the grid. To combat that, many schools are leaning on solar energy for charging.
States with 1/2G bus programs
California leads the U.S. in developing and adopting 1/2G school bus technology.
Its largest project is at the Oakland Unified School District, where Pacific Gas & Electric and transit provider Zum operate a fleet of 74 buses estimated to generate 2.1 gigawatt-hours of electricity annually.
A separate Zum project with the San Francisco Unified School District is set to launch next month. It is expected to surpass the Oakland project, with a starting fleet of 104 buses returning about 3 gigawatt-hours of energy annually during peak hours. The fleet will more than double to 238 electric buses in 2027-2028.
California mandates that electric school buses funded through state programs be equipped for 1/2G capability. It is funding some 1/2G infrastructure programs and has the state's largest utilities — PG&E and Southern California Edison — as partners.
In Connecticut, the Branford Public Schools district will have 46 1/2G-capable electric buses in August.
In North Carolina, Cherokee Boys Club will operate 21 electric school buses for tribally controlled Cherokee Central Schools. It has a 1/2G test program funded by Duke Energy. Cherokee Boys Club service manager Donnie Owle is working on a project to use the buses as generators for school buildings that double as emergency shelters.
Daniel Thomas, director of administrative services at South Florida's Glades County School District, does not have funding for 1/2G but plans to use 13 Blue Bird electric buses as cooling centers when the next hurricane strikes.
"We hope it never comes, but this is Florida," Thomas said.
