Most people are familiar with at least the idea of natural gas for its uses around the house -- stovetop cooking, home heating and keeping water hot for washing dishes, clothes and people. But in the United States at least, it may come as a surprise to ordinary car owners to know that it also makes an excellent alternative fuel for vehicles, especially fleets.
In the United States, compressed natural gas (CNG) and liquefied natural gas (LNG) are commonly used as a much cleaner fuel for city buses. Since natural gas has the lowest carbon concentration of any fossil fuel, emissions from burning it are far lower than those for gasoline or diesel. Refueling can be done by tapping into natural gas lines, since they are pressurized enough to force gas into a vehicle’s empty compressed-natural-gas fuel tank.
Outside the United States, in countries that are more sensitive to oil price gyrations, natural gas vehicles make up a much greater percentage of the vehicles on the road. In Pakistan, for instance, 61 percent of vehicles run on natural gas.
Since natural gas quickly rises in air and dissipates, it’s a far safer fuel than gasoline. And for now, it’s relatively inexpensive. In parts of the United States, a gallon equivalent of natural gas can be had for about $1! It’s easier on engines because its low carbon content leaves little in the way of deposits or engine-destroying impurities. Converting regular gasoline engines to natural gas is a pretty straightforward process, but at around $6,000 and up, is still pretty expensive in the United States.
Disadvantage: Because of a lack of infrastructure, it’s hard to find a filling station for purpose-built and converted natural gas vehicles. But for fleet owners, it could be worth the investment to have existing on-site natural gas lines plumbed in to create their own refilling facility.
The next fuel on our list has been growing in popularity because you can “grow” more of it when it’s used up. To find out what it is, read the next page.