Hybrid bus makes the rounds on Vail routes
Vail may get its own hybrid as soon as ’06
It can be hard to tell when the world changes.
That’s exactly the point of a new bus that was making the rounds in Vail . The bus on loan to Vail’s transportation department used “hybrid” diesel-electric technology developed by General Motors and its Allison Transmission division.
The vehicle promises better fuel economy, lower exhaust emissions and quieter operation. Mostly, though, this revolutionary vehicle promises to be, well, a bus.
While the hybrid technology comes with revolutionary levels of fuel economy and exhaust emissions, the vehicle still has to fulfill its mission as a mass transit device, something it apparently does very well.
“I drove it a lot,” said Joyce Rihanek, a town of Vail bus driver. “It’s just a bus.”
Like hybrid passenger cars, the bus that traveled around Vail had an internal combustion engine much smaller than comparably-sized vehicles. In this case, the engine was a Cummins turbo-diesel commonly found in heavy-duty Dodge pickups. For a pickup, it’s a big motor. For a bus, it would be woefully undersized if not for the electric motor that’s the secret of hybrid technology.
Because of hybrid technology, the bus may be a little quicker in town than a conventional vehicle. Also, the electric motors mean the engine in the back of the bus rarely rises above idle when it’s rumbling down the road. The combination of a smaller motor that’s under load only occasionally is the reason GM claims its hybrid technology can save as much as 60 percent on fuel costs. GM also claims the vehicle’s emissions are as much as 90 percent lower than conventional buses.
The fuel savings are important, since a hybrid bus currently costs about $100,000 more than a conventional vehicle. Factoring the fuel and other savings, though, buying a hybrid can make financial sense, Vail Transportation Director Mike Rose said.
Beyond the fuel savings, there could be maintenance savings as well, Rose said. While other hybrids use the brakes to charge the batteries – turning the kinetic energy from slowing the vehicle into electricity – the GM system does that “regenerative braking” through the transmission. That means when a driver lifts off the accelerator, the bus slows down, and quickly.
“The braking transmission is one of the biggest pluses to this bus,” Rihanek said. “Except for bus stops and stop signs, I hardly used the brakes. You can control almost everything with the accelerator. It’s pretty neat.”
Rose said with the transmission doing most of the work of slowing the bus, it will probably need brakes less frequently than conventional vehicles. That could also translate to less brake squeak at stops. The hybrid is also less noisy and stinky than conventional buses.
Better yet, hybrid technology is at the point financially where it can make sense for a transit department, Rose said.
The town’s existing buses cost about $1.25 per mile to operate, Rose said. While it’s argued that a hybrid can be run for about the same price over the long haul, that hasn’t been the case on the Front Range. The hybrid buses in use on the 16th Street Mall in Denver cost $5 a mile or more to run, said Rose, mainly because of maintenance costs.
“This is a much simpler system,” Rose said.
Which is why there are hybrid buses in Vail’s future. The town has a hybrid in the budget for 2005, pending receipt of some federal mass transit grants. The town can’t order the bus until the grants are in hand, though, Rose said, so the vehicle probably won’t be delivered until 2006. Other vehicles are in the replacement plans for 2008 and 2010.
“People seem to like it,” Rihanek said. “I think the guests will notice.”
What a hybrid does
Hybrid technology doesn’t do away with the internal combustion engine. An electric “helper” motor means vehicles can use smaller internal combustion engines. The electric motors use batteries charged by “regenerative braking,” meaning the brakes charge the batteries using kinetic energy generated by slowing the vehicle.
The system used on the General Motors’ Allison system on display in Vail uses the transmission for the regenerative braking function, meaning the battery is charged whenever a driver eases up on the accelerator.
According to GM, its hybrid bus technology:
– Reduces particulate emissions up to 90 percent over a conventional bus;
– Reduces hydrocarbon emissions up to 90 percent;
– Reduces oxides of nitrogen up to 50 percent;
– Reduces carbon monoxide emissions up to 90 percent;
– Increases fuel mileage by up to 60 percent.