REFUELING stations for vehicles that burn compressed natural gas (CNG) have been opening at the rate of three a week as sellers of the alternative motor fuel prepare for the impact of the 1990 Clean Air Act Amendments.
Under that law, government and private fleet owners in the 22 most polluted cities must switch to "clean" fuels, beginning with 30 percent of the new cars and light-duty trucks they buy in 1998 and increasing thereafter.
An even harder push for alternative fuels may come from the national energy strategy legislation pending in Congress. The Senate version would advance the purchase timetable for federal fleets to next year and for state fleets to 1995. And it would expand the list of affected cities to those with populations larger than 250,000. The House version would provide a tax deduction for equipment to convert vehicles and build refueling facilities.
With the United States government taking a carrot-and-stick approach - mandating as well as subsidizing alternative fuels - the question is whether the market will favor CNG, gasoline/alcohol blends, propane, or electricity.
"There's going to be a showdown," says Norman Bryan, vice president of clean-air vehicles at Pacific Gas & Electric Company. "Among hydrocarbon fuels, CNG will win."
"Three years ago methanol looked like the leader," adds Michael Libbey, a spokesman for Chevron Corporation in San Francisco. However, methanol has the drawbacks of being highly explosive, corrosive, and toxic. And it causes emissions of toxic formaldehyde to soar.
Chevron once planned to open 25 facilities in California to sell M-85, a gasoline blend with 15 percent methanol. But demand has been far below state projections. Chevron recently decided to keep its 14 M-85 stations but not to add more. The company plans to open several for CNG.
Proponents say natural gas is:
Cheap. On average CNG sells for 70 cents per equivalent gallon of gasoline, although in some regions it might cost as much as a dollar, the American Gas Association says. Converting a car costs $2,000 and up, but Detroit has just started to turn out its first CNG cars, trucks, and vans.
Clean. The Natural Gas Vehicle Coalition (NGVC) says that compared to gasoline, CNG produces 90 percent less carbon monoxide, 80 to 93 percent less reactive hydrocarbons, and 12 to 32 percent less carbon dioxide. CNG produces up to 65 percent less nitrogen oxides, but in some cases makes more NOx than gasoline, other sources say. In addition, CNG burns so cleanly that engine oil can last 50,000 miles and spark plugs 75,000 miles.
Abundant. The United States has an estimated 50-year supply of natural gas, not counting reserves in Alaska, the NGVC says.
Available. CNG stations can be supplied by the same million-mile pipeline system that delivers natural gas to 50 million homes.
Safe. Natural gas is lighter than air, so if released it dissipates. It is neither corrosive nor toxic. The pressurized tanks that hold CNG are far tougher than sheet-metal gasoline tanks. CNG vehicles have a significantly better safety record than gasoline-powered cars, the NGVC says.
But what good is a CNG-powered car if you can't fill it up? Nationwide there are still only 500 refueling centers, of which half are not open to the public. So companies in the oil, gas transmission, and local gas distribution businesses have been opening the stations at great expense ($300,000 or more each) in order to develop business.
"I think by the end of the decade that you will have 25 to 50 million vehicles in America on natural gas," says NGVC chairman T. Boone Pickens, who telephoned from his CNG-powered Cadillac in Dallas traffic.
That's an astonishing projection, considering that maybe 50,000 of the nation's 200 million cars now run on CNG. Mr. Pickens says half the growth will come from among the 15 million to 30 million fleet vehicles and the rest from individuals.
Pickens, who controls a natural gas production company, says he was struck a year ago by the fact that natural gas has a hard time competing against coal and residual fuel oil for power generation, yet bests gasoline easily in the transportation market. "What I'm trying to do is get natural gas into the market that we should have been in from the outset."
But Chevron, the nation's largest producer of natural gas, doubts CNG will ever be more than a niche fuel. "Gasoline is still the elephant on the block," Mr. Libbey says.