Greening Garbage Trucks

Jim Cannon

EACH WEEK, more than 100,000 refuse collection trucks drive down virtually every street in the United States to remove the clutter, smell and health risks created by millions of tons of garbage. Our communities are livable because this vital service is routinely performed, but the price is high. Diesel-fueled refuse trucks create air pollution, disturbing noise and a hefty bill for imported oil.

But, change is on the horizon, says New York-based INFORM Inc., an environmental research organization. Research presented in the organization's new report, “Greening Garbage Trucks: Trends in Alternative Fuels Use, 2002-2005,” has found that fleet operators are turning to clean burning and domestically produced alternative fuels to offset the costs of rising diesel prices, meet stricter engine emissions standards, address public health issues and allay national security concerns. While a few fleets are experimenting with biodiesel, hybrid drivetrains and biomethane, many have begun using natural gas.

The report shows that the number of natural gas refuse trucks in the United States has steadily increased in the past seven years. In 1998, only 240 natural gas refuse trucks were operating in the country. By 2005, the number had grown to 1,496, and projections estimate that 2,221 of the vehicles will be in service by 2010.

The increased use of natural gas refuse trucks has been spurred by the advantages natural gas offers over diesel. From an economic standpoint, natural gas costs less per gallon equivalent than diesel, even though the price for both fuels escalated considerably in 2005. For example, at the end of September 2005, the quarterly Alternative Fuel Price Report, published by the U.S. Department of Energy, reported the national average price for compressed natural gas as $2.36 per diesel gallon equivalent and the national average price for diesel as $2.81 per gallon.

Natural gas engines also run more cleanly than diesel engines, emitting less particulate matter, carbon monoxide and nitrogen oxides (NOx), which have been known to harm human health. Additionally, natural gas engines are significantly quieter than diesel engines, which can generate noise levels as high as 100 decibels. This is a decided advantage for natural gas, because refuse collection vehicles often operate on residential streets during early morning hours.

Using natural gas as a fuel also helps reduce the country's dependence on foreign oil. Natural gas can be produced domestically or imported from Canada. On average, a refuse truck travels 25,000 miles per year, burning approximately 8,900 gallons of diesel fuel. Replacing 50 percent of the 136,000 diesel refuse trucks in the United States with natural gas trucks would displace 15 million barrels of oil annually.

Despite the advantages, INFORM found that natural gas refuse trucks constitute less than 1 percent of the overall refuse truck fleet in the United States, and the overwhelming majority of the trucks — nearly 85 percent — operate in California. Two factors explain their concentrated use in California. First, in 1991, the South Coast Air Quality Management District mandated that operators of municipal fleets that contain more than 15 heavy-duty vehicles buy natural gas-powered vehicles. Second, California provides heavy-duty private fleets with public funds to support the purchase of alternative fuel vehicles.

On the national level, several recently enacted federal tax incentive programs may increase the number of natural gas refuse trucks in other states. The 2005 Energy Policy Act includes nearly $1 billion in financial incentives for alternative fuel vehicles. It provides a tax credit of up to $32,000 (or 80 percent) for the incremental cost of natural gas trucks and a tax credit of up to $30,000 for the cost of new fueling station equipment for alternative fuels. The 2005 Highway Bill created a federal excise tax credit equal to $0.50 per gasoline gallon equivalent of alternative fuel.

Another factor that may encourage fleet operators to purchase natural gas vehicles is the implementation of the U.S. Environmental Protection Agency's stricter emissions standards, beginning with model year 2007. For NOx emissions, the natural gas engines that will be available in 2007 will be certified at 0.2 grams — 1 gram less than the set standard of 1.2 grams.

Diesel engines will likely require the addition of complex and costly engine controls and aftermarket treatment systems to comply with the standards. A 2005 study conducted by the Cupertino, Calif.-based research firm TIAX estimated that the new requirements for diesel engines will erase the cost advantage that diesel refuse trucks have previously had over natural gas trucks.

Thus far, fleet operators pioneering natural gas refuse truck programs are acting as solitary players, not as a group. A new trade group is needed to help advance the widespread use of natural gas refuse trucks. The group could find a home within an existing refuse industry or natural gas vehicles trade group, or it could operate independently. If the industry could organize itself to exchange information, publicize experiences with natural gas refuse trucks and negotiate joint bulk truck orders, the use of natural gas refuse trucks could expand quickly, providing greater public benefits in the process.
— Jim Cannon
Senior Fellow, INFORM Inc.
New York