CTTransit Tests Confirm Improved Hybrid Bus Performance

18-month hybrid diesel bus demonstration showed 10 percent better fuel economy than the newest diesel buses and 303-35 percent improvement over existing fleet.

Published: 26-Jan-2005

class=text>CTTransit's two hybrid-electric diesel buses increased fuel economy and were more reliable than standard diesel buses, preliminary results from an 18-month demonstration reveal.

According to tests, the hybrid buses scored 10 percent better on fuel economy than the newest diesel buses, and were 30 percent to 35 percent more efficient than the existing fleet, said Stephen Warren, assistant general manager for maintenance service for CTTransit.

The hybrid buses also cost less to maintain and got rave reviews from bus operators, Warren said.

"They were much more reliable than our diesel buses in virtually every category, which was a surprise," he said. "The drivers also thought they had better acceleration."

In June 2003, the state received two hybrid buses, designed by New Flyer Bus Co., as part of a 10-city demonstration. They were tested in Hartford before they were sent last summer to Stamford, where they will stay.

Riders probably didn't realize they were on a hybrid bus -- one of the few outward differences is that they are 3 inches taller than a regular bus. The big difference is in the technology.

Each hybrid bus has two electric motors designed into the transmission, an internal combustion clean diesel engine and a 2,000-pound battery pack on the roof.

The hybrids cost more. At $500,000 each, they are about $225,000 more than a diesel bus.

Last fall, the buses got high marks for environmental efficiency. They were awarded the Connecticut Quality Improvement Award silver innovation prize, given to "innovative programs that improve quality, performance and marketplace competitiveness."

CTTransit is awaiting the results of emissions tests. The buses were expected to reduce emissions by about 20 percent, but the company won't know for a few months, Warren said.

CTTransit hoped for slightly better fuel economy, he said, but because the buses did well in mechanical efficiency and environmental benefits, more will be welcome when the time is right.

State Department of Transportation officials said it would be difficult to add hybrid buses because of the cost.

"The capital costs are quite a bit higher, but they are better than the ones they replaced in terms of fuel economy," said Michael Sanders, transit administrator for the DOT.

If the state were to add more buses, "we wouldn't be doing it for financial reasons" but for environmental benefits, he said.

Nationally, hybrid buses have become popular in such large cities as Seattle, Philadelphia and New York, said Lurae Stuart, senior project manager of the bus technology program for the American Public Transportation Association. Smaller cities such as Stamford may wait for the cost to come down, she said.

"The cost is an issue for everybody," she said. "I think the smaller agencies are waiting for big orders to bring the costs down."

Seattle should have about 250 hybrid buses later this year, she said. Cities such as New York particularly can benefit from the improved fuel efficiency because the buses perform better in stop-and-go traffic, she said.

"If you think of 10 percent of New York's fuel budget, that can buy a lot of vehicles," she said.



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