Who said a hybrid vehicle has to have a battery storing electricity? Georgia Tech students are currently working to convert a classic school bus into a hydraulic hybrid under a project sponsored by Ford with $50,000 and cheered by the local school districts and not only.
Basically, this kind of mechanical approach to a hybrid vehicle uses a pump that charges an accumulator from the bus’s diesel engine and releases the stored energy when the bus accelerates. When it brakes, the pumps work on reverse, just like electric regenerative brakes work on a Prius, for example. The conversion team hopes to get fuel savings of up to 20 percent and that the conversion will pay for itself in a relatively short time. Pessimistic (or, better said, realistic) estimates say that five years would be a good match.
The team of three grad students and five undergrads, led by their mechanical engineering professor Dr. Michael Leamy, say 85 percent of the project is already complete. They have designed the new drivetrain, custom made parts and installed them during the past eight months. “At present, the transfer case is mounted with one accumulator,” he said. “The microcontroller is fully programmed and the sensors are installed.”
Hydraulic hybrid systems are best suited to heavy trucks in stop-and-go traffic, and had been tested before by Chrysler. The company even equipped the UPS truck fleet with such hybrid systems back in 2008, and are now improving the technology in collaboration with the EPA.
Now, that’s an interesting point of view I never thought about. Systems like this should have appeared two or three decades ago, and we wouldn’t have entered the energy crisis so soon.