July 29, 2010 By Russell Nichols
To launch its single-stream recycling program, Ann Arbor, Mich., officials didn't have to look far to find a solution that could save money and fuel.
In July, the city became the first in Michigan to purchase hydraulic hybrid trucks, built using technology pioneered by the U.S. Environmental Protection Agency's National Vehicle and Fuel Emissions Laboratory in Ann Arbor. Used for recycling collection, these garbage trucks don't store energy in batteries like most hybrid cars. Instead, the new hybrid system stores braking energy in hydraulic fluid, which then propels the trucks at initial acceleration. This makes the technology ideal for heavy-duty vehicles that do a lot of stop-and-go driving, such as shuttle buses and garbage trucks, because it boosts efficiency and keeps costs low.
"There are more options than ever before to help people, businesses and government save money at the pump, reduce our dependence on oil and improve air quality," according to Sean Reed, founder and executive director of the nonprofit Clean Energy Coalition (CEC), an organization dedicated to expanding clean energy technologies in the state. "The role we take is to try to secure the funding necessary to make these things a total no-brainer."
With a $40,000 price tag per truck, the solution wasn't cheap. But on behalf of Ann Arbor, the CEC secured a subgrant of about $156,000 from the American Recovery and Reinvestment Act to cover those costs, Reed said.
"There are CECs all around that can help other municipalities as well," said James W. Parks, manager of communications for Eaton Corp., which manufactured the Hydraulic Launch Assist (HLA) system added to the trucks. "It's certainly helpful when there are incentives for the end-user."
According to Eaton Corp., the city can expect fuel economy savings of up to 30 percent compared to a conventional diesel powertrain, and see return on investment in two to three years. The city estimates saving 1,000 gallons of diesel gas per truck every year, which equates to $73,000 in fuel savings and $26,500 in reduced maintenance costs for its four trucks over the 10-year service life. Also, with the new system, emissions should be cut down 20 to 30 percent, and the trucks should only need one brake job a year instead of four.
Eaton touted other benefits of the hybrid trucks such as reduced launch noise (a hydraulic-powered launch is quieter than the diesel launch) and reduced braking noise, a common neighborhood complaint with large trucks.
The HLA system launched last fall, which puts Ann Arbor's trucks among the first 25 deployed nationally with the hybrid technology, said Vince Duray, chief engineer at Eaton Corp. Other Eaton units have been shipped to Dallas/Ft. Worth and Houston.
According to Chris Grundler, chief executive of the EPA's National Vehicle and Fuel Emissions Laboratory, heavy trucks account for about 20 percent of the nation's man-made emissions of carbon dioxide. Emissions from heavy trucks are growing faster than passenger cars.