Researchers from the University of Waterloo have invented a new system for idling buses and delivery trucks that could reduce environmental impact and save companies and governments money from fuel costs.
The research team has discovered a way to capture the waste energy from service vehicles as they are idling and slowing down. They also figured out how to use this extra energy to replace fossil fuels currently used to operate secondary systems, like air conditioning, when the vehicles are idling.
A commercial truck that could benefit from the developments. (Source: U.S. Air Force/Lisa M. Macias)
"An idling vehicle essentially operates at five percent efficiency, meaning the vast majority of fuel a bus or delivery truck uses when it is stopped is being wasted," said Amir Khajepour, a professor of mechanical and mechatronics engineering at Waterloo and the study's lead author. "By harnessing the energy a vehicle wastes as it is slowing down and redirecting it to a secondary battery system, these vehicles can be turned off without shutting off systems such as refrigeration and air conditioning units.”
During the study, researchers observed the driving, braking and idling patterns of service vehicles. They then used computer models and engines they hooked up to secondary battery systems in the lab. Then they simulated the vehicle’s patterns and determined how to collect and use their waste energy.
The researchers chose to study service vehicles instead of passengers vehicles because service vehicles have significant auxiliary power needs for systems that are on board, like refrigeration. Systems like these account for a big portion of the vehicle’s fuel consumption.
"Given that most companies or governments cannot afford to transition their entire fleets over to cleaner vehicles all at once, this system could represent a cost-effective way to make current vehicles more fuel efficient in the short term," said Khajepour.
The money that companies and governments could save with this technology has potential to pay for a new secondary power system in one or two years.
The study was published in Energy.
