It's a common sight in cities around the world: a noisy bus spewing a black cloud of diesel smoke. But starting February 16, students at the University of Vermont's campus have been riding on two new buses that are much cleaner and quieter.
Their secret? The buses run on compressed natural gas.
The CNG fleet, which will grow to six vehicles by fall 2008, is the product of a partnership between UVM, the City of Burlington, Vermont Gas Systems Inc., and the Federal Transit Administration to improve air quality and develop Vermont's first "fast-fill" natural gas refueling station.
Senator Patrick Leahy provided key leadership on the project, securing a $2.4 million appropriation for the program through the Federal Transit Administration.
"Using cleaner alternative fuels for these buses is a natural for Burlington and for UVM," said Leahy. "The collaboration between UVM, the City of Burlington, and Vermont Gas to move forward with this process will boost the livability factors that help make Vermont such a great place to live. I'm proud that this CNG project will help keep us at the forefront of efforts to reduce our dependence on foreign oil, clean our air, and provide quality transit options for the Hill institutions."
"These clean-burning new vehicles represent a significant advance over older technologies and are a fitting symbol of UVM's wide-ranging commitment to the environment," said UVM president Daniel Mark Fogel. "We're especially grateful to Senator Leahy for his ongoing support of this project and to the City of Burlington and Vermont Gas for being both partners and advocates for this important technology."
"This is a significant step for the city and the university, working cooperatively to address vehicle emissions," said Burlington Mayor Bob Kiss. "We know much remains to be done and we're appreciative of the support from Senator Leahy and the Federal Transit Administration."
The new CNG refueling station at the city's department of public works will allow each bus to fill its rooftop tanks in just a few minutes. After the university's transit fleet has been serviced, excess capacity in the system can be used by in new heavy-duty natural gas vehicles the city plans to put into service, like street sweepers and recycling trucks.
Though the city has been running a few vans on natural gas for several years, they take hours to refill from a low-pressure tank; this new technology is suited to rapid refill of large vehicles and is the first of its kind in Vermont.
Benefits to public health and the environment
Supplementing the funds secured by Senator Leahy are matching funds from UVM, the city, and other partners, which "bring the total project costs to about $3 million," said Dan Bradley, transportation planner for the city.
It's an investment in public health. Motor vehicles are the largest source of toxic and cancer-causing air pollutants in Vermont. "Particulate pollution on these CNG buses should be about 100 times lower than what you get from typical buses," said UVM engineering professor Britt Holmen, an expert on vehicle emissions.
And, compared to petroleum diesel, compressed natural gas emits about 50% fewer nitrogen oxides (sometimes called "NOx"), a major contributor to smog, greenhouse gas formation, and, like particulate pollution, a cause of respiratory health problems. As an added benefit, natural gas engines reduce noise pollution; they are about 15 decibels lower than diesel.
Next logical step
The new CNG buses are part of a long-term commitment by UVM to use environmentally friendly alternative fuels in its campus area transportation (CATS) fleet. For several years, the university has been running its buses on B20, a mix of 20% biodiesel, a cleaner vegetable-based fuel, and 80% petroleum diesel.
"Our use of biodiesel was pioneering when very few other universities were making this step to a cleaner fuel. Now CNG is the next logical step in UVM's commitment to reducing emissions. It will be a good complement to the biodiesel that will continue to fuel some of our smaller buses," said Gioia Thompson, UVM's environmental coordinator.
And all new buses, diesel and CNG, are built with cleaner engines than what was available a decade ago. "If you go from a 1998 model year to a 2007 you've already improved by an order of magnitude the emissions standards for that vehicle," Holmen said.
Natural gas vehicles date back at least into the 1930s, and today natural gas is well established as safe transportation fuel, having been on the road in California, Colorado and many other states and foreign countries for years. "There are now hybrid electric engines available," said Dan Bradley, "that are also a good alternative to diesel, but they are not as well-tested and there are fewer options than with natural gas."
"CNG is a mature fuel," he said, noting that natural gas has an established distribution network, is less expensive than diesel, and that numerous types of heavy equipment, like the new trucks and vehicles the city will use, are available with natural gas engines.
Benefiting the local economy
In addition to their cleaner, safer emissions, CNG buses offer other advantages.
The new buses help reduce dependence on imported oil; over 99% of natural gas consumed in the U.S. is produced in North America, according to the California Energy Commission.
The building of compressed gas delivery systems-like the new tanks and equipment at the city's public works building- could support clean-burning hydrogen vehicles in the future. In the near term, blends of hydrogen and natural gas could be available, and as the technological problems that hydrogen now faces are overcome, the CNG equipment could be converted for use in a straight hydrogen delivery system.
The new vehicles and fueling station also fuel the regional economy. The 41-foot buses-air conditioned, handicapped accessible, and with 20% more seating capacity than UVM's current school buses-are built by the Orion bus company in Oriskany, NY. The new fueling station at 645 Pine Street was built by Smalley Contractors of Rutland, VT.
For both the university and the city, the long-term goal is to run cost-effective vehicles that produce zero emissions fueled from renewable energy sources, like solar and wind power. But that appears to be years away and in the meantime ground-level air pollution-with heavy diesel vehicles like buses being a major culprit-is a leading cause of respiratory and other health problems. CNG buses reduce this problem today.
"Natural gas is a bridge technology," said Katherine Decarreau, director of UVM's transportation and parking services. "They're a great choice for now, and when they need to be replaced, we'll have a clearer sense of what the next best technology will be."
