Waste energy used to power secondary system for service vehicles
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Canadian researchers have created a new power system for service vehicles which could reduce emissions by capturing and redirecting unused energy.
Service vehicles such as delivery trucks tend to suffer from higher power consumptions than passenger vehicles, thanks to the common requirement of auxiliary power needs for secondary systems such as air conditioning, or refrigerators in food transport or ice cream vans.
A team of researchers at the University of Waterloo saw an opportunity to reduce the fuel inefficiency of service vehicles by harnessing wasted energy and redirecting it to power their secondary systems.
“An idling vehicle essentially operates at five per cent efficiency, meaning the vast majority of the fuel a bus or delivery truck uses when it is stopped is being wasted,” said Professor Amir Khajepour, a professor of mechanical and mechatronics engineering at the University of Waterloo and lead author of the study.
“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.”
In Energy, the researchers report examining driving, braking and idling patterns of various service vehicles, which account for a significant fraction of their fuel consumption.
Using computer modelling with engines hooked up to secondary battery systems in the laboratory, the researchers simulated the different routes service vehicles follow. Using these simulations, they were able to determine how to most efficiently collect and redirect waste energy.
The waste energy is captured as the vehicles slow down and is redirected to replace the fossil fuels normally required to operate secondary systems when the vehicles are at a standstill. This could significantly reduce the environmental impact of idling buses and trucks.
“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 Professor Khajepour.
According to the researchers, the savings made from reducing fuel consumption could pay for the new secondary power system in as little as one to two years, and save companies and governments millions of pounds every year in fuel costs.