Natural Gas Vehicles Burn Cleaner and Cheaper

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By Bill Siuru

Is it more efficient to use wind or solar power to generate electricity for the electric grid or use it to produce hydrogen for fuel cell vehicles? How about burning biomass materials to produce heat and electricity versus turning it into ethanol? These questions will have to be answered, probably from an economic view, as we move from petroleum to alternative fuels and technologies.

Nearer term, should natural gas be used by powerplants or as a transportation fuel? As alternative technologies like wind, solar and geothermal mature and perhaps nuclear regains favor, should they replace the natural gas that is now widely used for power generation? While natural gas resources are quite huge and in friendly locations, they are not unlimited. Thus, the need to choose wisely.

While natural gas doesn’t get much press, its use in vehicles is growing quietly. There are over 150,000 natural gas vehicles (NGVs) on American roads today and over five million worldwide. Serving these are over 1,500 NGV fueling stations in the U.S., with over half of these available for public use.

This is happening even though most auto manufacturers no longer have NGVs in their lineups. In 2000, some 15 cars and light trucks fueled by CNG (compressed natural gas) were available from DaimlerChrysler, Ford, GM, Honda, and Toyota. By 2007, the Honda Civic GX was standing alone. If you want a light duty NGV other than that Civic, it probably has to be a conversion. The situation is better for original equipment manufacturer (OEM) medium- and heavy-duty trucks and buses fueled by CNG or LNG (liquefied natural gas).

A Natural At Airports

One of the largest users of NGVs is Los Angeles World Airports, which includes Los Angeles International (LAX), Ontario International (ONT), Van Nuys (VNY), and Palmdale Regional (PMD) airports. LAWA has been using natural gas since 1993. According to David Waldner, LAWA’s Assistant Director for Construction and Maintenance, use of natural gas is driven by emissions reductions and their “Green Airports” philosophy, not by any economic benefits...”although with petroleum prices these days, there is the benefit of lower fuel costs,” Waldner says.

Both CNG and LNG are used, along with propane. About half of the LAWA fleet operates on these fuels. Currently, there are 468 NGVs at LAX, 43 at ONT and 18 at VNY. These include sedans, pickups, shuttle buses, medium/heavy duty trucks, forklifts and sweepers. The entire courtesy shuttle fleet at LAX runs on LNG. To keep this fleet fueled, a state-of-the-art, high-technology LNG/LCNG fueling station was built at LAX and a low-cost CNG fueling station was built at VNY.

LAWA is not the only organization using natural gas shuttles at LAX. Destination Shuttle Services operates 19 General Motors 22-passenger buses with Vortec 9.1 liter engines that have been converted to CNG. According to the company’s CEO, Jack Lott, running on clean natural gas offers a positive environmental statement that seems to carry a lot of weight with the public. He notes that the cost of running on CNG is about the same as running on regular fuel, with lower fuel costs but reduced fuel economy due to greater vehicle weight because of the number of CNG tanks required for a desired driving range.

Clean Taxis

Natural gas has been a modest success in taxis, especially in large cities with air pollution problems. CNG taxis are in service in Atlanta, Las Vegas, Los Angeles, Toronto, and Washington, D.C. Some taxis rack up 50,000 to 100,000 miles annually. Taxis are a great area of focus because of this high annual mileage. Replacing one gasoline taxi with a natural gas one nets about the same emissions reduction and gasoline displacement as replacing five to 10 personal-use or conventional fleet cars driven an average of 10,000 miles per year.

Over 300 New York City Medallion cabs have been converted to run on CNG, many of which travel 100,000 miles or more annually. The New York City Clean Fuel Taxi Program provides funds toward the purchase of new natural gas taxi cabs or the conversion of gasoline cabs to natural gas. Besides reduced exhaust emissions, CNG vehicles do not release fuel vapors while refueling or due to fuel heating during vehicle operation. Operators generally say they are better to drive than gasoline vehicles and have lower maintenance costs, longer life expectancy, and lower fueling cost. There’s another plus: Drivers, who are often in their cabs for up to 12 hours at a time, also prefer natural gas taxis because of their lower emissions.