By using electric power as well as diesel, hybrid buses cut pollution and ambient noise. Time will tell if they also save money.
Quieter, cleaner and more fuel-efficient mass transit coasted through Southwest Minneapolis in late December relatively unnoticed, when Metro Transit deployed their first-ever diesel-electric hybrid bus on Route 18, Southwest to downtown's Nicollet Mall.
The buses use less diesel fuel by capturing energy from braking. Metro Transit officials said based on the technology, they expect a 50 percent reduction in emissions and up to a 40 percent fuel savings. The bus may be easier on the ears, since many say the buses are also quieter.
Even though the bus has only 3,000 miles of service so far, Metro Transit officials said they've received positive reports from drivers and riders. Metro Transit will deploy two more hybrids in August. But because the bus looks the same as any other, many riders barely notice the difference.
"It doesn't seem any different," said bus rider Bernice Halberg, a Richfield resident taking Route 18 with her 18-month-old son Dylan through Southwest into downtown.
Eric Dille, taking the bus to Minneapolis Community Technical College, 1501 Hennepin Ave., said he didn't really care if it was a hybrid, as long as it got him where he needs to go. But he said that he noticed little differences. "It sounds quieter," Dille said, "and the seat configuration is different."
The new technology, funded partially by a federal grant, has grown in popularity since a 1998 New York City trial.
New York City Transit maintenance official Dana Lowell said riders often don't notice a hybrid because its exterior looks the same but "when they are told that the bus they are riding is very low-polluting because it's a hybrid, the reaction from passengers is universally positive."
How does it work?
Jan Homan, Metro Transit's director of maintenance, said the hybrid bus is "the way of the future," operating with advanced technology including two computers on-board.
He said the hybrid bus has a smaller diesel engine than a regular bus and stores extra energy in a battery pack estimated to last six years. To charge the battery, the bus has what's called regenerative braking --the batteries are charged every time pressure is applied to the brake.
He said when the bus goes from zero to 10 miles an hour, it relies on electrical energy. Homan said this allows the bus to remain quieter as it approaches and leaves bus stops, and use less gas. Despite the smaller engine, he said the buses are much more powerful and faster than other buses.
Bob Gibbons, Metro Transit's director of customer service, said there are great advantages to the hybrid-bus technology, including fewer emissions. The major pollutants emitted by buses are nitrogen dioxide and particulate matter, also known as soot, Gibbons said. The hybrid bus is expected to cut those emissions in half.
Saving fuel is another major plus. Gibbons said a regular bus gets 3.7 miles per gallon, but because the hybrid replaces some diesel power with electricity, manufacturers claim it will get 5.2 miles to the gallon, a 40 percent fuel savings.
Gibbons said Metro Transit is now testing those claims by monitoring its bus. If true, Metro Transit could save $3.6 million a year if the entire fleet was hybridized.
One hybrid disadvantage is rider capacity. Metro Transit bought a "low-floor" bus with 35 seats, compared to 43 on a normal bus. (This was Metro Transit's choice, not a hybrid requirement.) People can board the bus in one step. The seats face each other and the rear door is twice as wide.
Halberg, with infant in tow, loved the lower floor and wider door, since it's easier to board with a child and a stroller.
A major disadvantage is cost -- the city's hybrids, priced at $490,000 each, cost almost double a regular bus's $270,000. Homan said the hybrid cost is high because the technology is so new that it's not in mass production yet. "The costs have to come down to make this possible," he said.
Gibbons said the high purchase cost is justified because running these hybrids in Southwest is an experiment with a more efficient technology. A federal grant paid 80 percent or $1,176,000 of the cost of the three hybrid buses, while Metro Transit picked up the other 20 percent.
He said because the cost is so high, Metro Transit won't convert substantial parts of its fleet to hybrids until other cities prove it's worth it. "We'll let other cities work out the wrinkles and once it's mass produced, we'll look at it," he said.
New York's experience
New York's Lowell said his transit system currently has 10 hybrids in service and another 325 on order. They are paid for through the city's general capital fund that buys the normal bus fleet, and New York state grant. He said New York has documented a 16 to 20 percent fuel savings so far, or between 1,500 and 1,800 gallons per year.
Lowell said New York's data hasn't matched the manufacturer's 40 percent claim because the New York hybrids were "first generation" -- the first in the nation to be put into service. "Buses that are now being put into service by Minneapolis and others are a second generation or third generation of the technology that has benefited from our experience," he said. "These buses will almost certainly approach or exceed the reliability of standard buses."