New York City's clean air buses striving to be the cleanest fleet in the world
The City of New York Department of Transport owns 1,280 buses and moves 114 million passengers annually, but the buses are actually operated by seven private companies. The department started a Clean Fuel Bus Program in order to migrate to being the cleanest bus fleet in the world. They wanted to reduce emissions, improve service and reliability, and reduce cost. Their plan was open to all technologies, and looked at replacing or retrofitting the diesel bus fleet with new technologies. The three main paths are expanding the use of CNG buses, buying hybrid buses, and getting clean diesel buses.
In service they found that the CNG buses were less fuel efficient than the diesel, less reliable and needed more service. The hybrids performed smoothly and performance could be customized in software. They did find that the batteries needed to conditioned periodically and more work was needed on the control software. The clean diesels eliminated most of the emissions but required low sulfur diesel fuel. Comparisons of emissions between the CNG and clean diesels generally favored the diesels. The two had similar particulate emissions and the diesel was much better in CO, HC and Carbonyl emissions. The CNG only had an advantage in NOx emissions, but not by much.
[Source: CleanAirNet]
Reader Comments (Page 1 of 1)
Robert 10:13AM (2/14/2007)
What has happend to the electric buses, trollys that ran off of overhead power lines, old technology, all electric, 0 emmision.
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Tim 11:47AM (2/14/2007)
Robert- Clean electric vehicles like streetcars were killed off by the oil companies and tire companies way back in the day. You can thank them for the noisy, dirty, smelly busses we are stuck with today.
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It is interesting to see that series hybrid electric busses turned out to be the most efficient, cleanest and required the least maintenance. GM, build the E-Flex! Ford, build the HySeries Drive!
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ronilateral-registrations 11:52AM (2/14/2007)
This would be worth digging into a bit: I believe these comparisons are between a diesel hybrid bus with a large emissions controls system and a CNG bus with almost none.
Therefore I would be skeptical about the reported maintenance costs, since the comparison is likely between older CNG buses and brand-new hybrid diesels.
How about adding a CNG hybrid using emissions controls to the comparison?
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breaking news 12:32PM (2/14/2007)
"... no later than December 31, 2003."
How old is this article???
Wait, archive.org claims it is at least 3 years old.
http://web.archive.org/web/20040622183015/http://www.cleanairnet.org/infopool/1411/propertyvalue-19514.html
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Chris M 9:19PM (2/14/2007)
San Francisco still has an eclectic electric transit system, with electric trolly lines, electric busses, hybrid diesel-electric busses, electric commuter rail (BART), and, of course, the 3 cable car lines (electric motors drive the cables). It would make for an interesting comparison on cost of operation - does the savings on motor maintenance exceed the costs of overhead wire maintenance? I suspect it does.
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