The price of natural gas is at record lows thanks to a shale drilling boom, giving it added credibility as an alternative energy source in the United States, with automakers jumping on the bandwagon.
Mark Hanson, an analyst at investment research firm Morningstar, said the use of natural gas instead of oil-based gasoline to drive the country's cars and trucks “is definitely starting to take off”.
“The economics seem to work,” he said, noting it was “just a question of what pace” the necessary infrastructure will take to develop.
David Cole, chairman emeritus of the Centre for Automotive Research, said gas was in focus as a potential engine fuel because “it is tremendously good fuel”.
Unlike petrol, whose rising prices are causing pain at the pump for consumers, natural gas is cheap in the United States as supplies bulge from production in the country's vast shale gas formations.
In addition, natural gas less carbon dioxide than petrol when burned. Thus, it is considered a “green” fuel even though in its raw state, the methane it emits is more destructive to the Earth's ozone layer than CO2, and the artificial fracturing of gas shales, known as “fracking,” has drawn fire from environmentalists.
There are several forms of natural gas used to power vehicles.
Compressed natural gas (CNG) is pressurised gas stored in a similar way to a vehicle's petrol tank.
Liquefied natural gas (LNG) is produced by chilling natural gas to about minus 160 degrees. It can be used as engine fuel for heavy ground or maritime vehicles.
In Europe, the fuel of choice for cars is liquefied petroleum gas, typically a mixture of butane and propane made from refined crude oil or natural gas.
Meanwhile, the three major US automakers are pumping out vehicles based on alternative fuels.
Ford has the largest array of alternative-energy vehicles: eight powered by natural gas, while the smallest US carmaker, Fiat-controlled Chrysler, early in March unveiled a pick-up truck than can use liquefied natural gas, which will go on sale in June.
Sergio Marchionne, the chief executive of Fiat and Chrysler, views natural gas as having greater potential than electricity to power vehicles.
General Motors, the US giant at the top of the global auto industry, produces two vans that use compressed natural gas, the Chevy Express and the GMC Savana, and will begin production by the end of the year on two pick-up trucks running on CNG.
GM has already sold 1200 vans to US telecommunications titan AT&T.
It’s working on a number of different alternative fuels, and particularly on electric vehicles, but GM spokesman, Dan Flores, said: “We think compressed natural gas offers a lot of potential. The technology is promising.”
It is particularly appealing to businesses, especially service providers such as telecoms, package deliverers like UPS, or to local governments, which operate trash removal or emergency vehicle fleets.
CNG vehicles operate at relatively short distances from a refueling hub. The economies of scale for a large business or public body can potentially justify the cost of an investment in the specialised refueling equipment.
RESTRICTED RANGE
For individual consumers, the refueling infrastructure is limited. And compressed or liquefied gas is expensive and requires substantial storage capacity, restricting the vehicles' range.
Morningstar's Hanson said that there were only about 400 CNG stations in the US.
In Europe, natural gas also is sparking interest amid rising gasoline prices, but so far it remains only a small portion of the market.
In France, for example, it represents less than one percent of the vehicle fuel consumed and only 200 000 of the country’s 31 million privately-owned vehicles run on liquefied petroleum gas - AFP