Bus fleets have long been early adopters of cleaner propulsion. New Yorkers, for example, can ride more than 2,000 buses powered by hybrid electric motors and compressed natural gas (CNG) engines, the largest such fleet in the world.
But scientists at GE’s global research labs are now getting ready to ditch carbon-based fuels altogether and zip into the “zero emissions” zone. They have developed an all-electric propulsion system that draws power from a combination of GE’s next-generation Durathon battery (efficiently stores energy), a lithium battery (provides pep and acceleration) and a hydrogen fuel cell (generates electricity).
“The system manages power, energy and the fuel cell all in an intelligent way,” says Tim Richter, systems engineer in the electric propulsion lab at GE Global Research. “For years fuel cells have been talked about as a clean transportation alternative, but cost has always been a roadblock to widespread adoption. With GE’s battery technology and dynamic dual battery management system, we are working on system solutions to both reduce fuel cell cost and increase the fuel cell longevity.”
Here’s what Richter means: A typical fuel cell must meet peak power demands of up to 150 kilowatts to make the bus speed up. The combination of the long-lasting, efficient Durathon, the speedy lithium batteries, custom software controls and power conversion hardware provides the bus with an efficient flow of power. It can cut the required fuel cell size by half to 75 kilowatts or less. With a price tag of almost $5,000 per kilowatt, this reduction significantly impacts the initial cost of the bus.
The market for this technology is large. There are almost 850,000 buses registered in the U.S. and many travel less than 100 miles per day. These buses, as well as and other heavy duty vehicles like pickups and garbage trucks, are the perfect candidates for the new dual battery and fuel cell design. Converting even a fraction to the zero emissions platform would dramatically reduce CO2 emissions and cut fuel consumption.