Published on November 7th, 2008 | by Stephanie Evans

Alt Fuels Comparison

Now, more than ever, it is imperative that viable, sustainable
alternatives to gasoline and diesel be found in order to reduce the
depletion of non-renewable resources, stop dependence on imported oil,
and safeguard the environment. Alternative fuels are also frequently
referred to as “clean-burning fuels” because they produce fewer emissions
than conventional gasoline and therefore support regulations such as
The Clean Air Act.

If you are considering buying a Low Emissions or
Zero Emissions Vehicle, understanding the various types of alternative
fuels will be key to making your decision.

Ethanol is perhaps the most widely known and widely available alternative fuel. It is an alcohol-based fuel that is made from fermented and distilled starch crops such as corn; it can also be made from other biomass sources such as trees and grasses. Gasohol or E10 is a blend of 10% Ethanol and 90% gasoline. Many gas stations carry this blend and it is approved for use in all automobiles, however since it is still composed primarily of gasoline it does not significantly reduce the use of gasoline. E85 is a blend of 85% Ethanol and 15% gasoline and Flex Fuel Vehicles (FFVs) operate on this blend, as well as conventional gasoline or E10. The cost of E85 varies depending on where you live, thus it may be cheaper than gasoline in some regions of the country and more expensive in others. Ethanol is a sustainable alternative because it can be domestically produced, reduces emissions, and FFVs are not dramatically more expensive for the consumer, however it does result in decreased mileage capabilities and it is currently expensive to produce, limiting its availability.

Natural Gas is an alternative fuel that has been gaining popularity in recent years in the form of compressed natural gas (CNG) and liquefied natural gas (LNG). It burns more cleanly than other fossil fuels, is less expensive, and typically is produced domestically. As a fuel, it is mainly comprised of Methane, but it must undergo extensive processing to remove almost all other materials to become fuel-ready. It is a desirable fuel source because it produces lower levels of smog-forming pollutants and reduced emissions of greenhouse gases compared to gasoline. However, it emits higher levels of greenhouse gases than typical hybrids and results in less miles per gallon of fuel. Also, natural gas vehicles are not being produced in large numbers at present, making them more expensive and less-readily available. The lack of natural gas fueling stations at present is also a hindrance.

Biodiesel is a safe, biodegradable, converted form of diesel fuel that is made from vegetable oils, animal fats, or recycled restaurant greases. Like Ethanol, blends of Biodiesel are frequently being used, including B2 (2% biodiesel and 98% petroleum diesel), B5, B20, on up to pure B100 made up of 100% biodiesel. At present most manufacturers of diesel vehicles do not recommend using blends higher than 5% and the use of higher blends results in significantly reduced fuel economy and power. Its advantages as a fuel source include domestic production, reduced pollutants and greenhouse gases, and its biodegradable and nontoxic properties. Some of its disadvantages are that it is more expensive, results in increased nitrous oxide emissions, and is typically not recommended for use in low temperatures, prohibiting its use in regions with colder climates.

Hydrogen is considered a very promising fuel source for the future. To power an automobile, it is placed in fuel cells to fuel an electric motor or it is burned in an internal combustion engine. Like other alternative fuels, hydrogen is environmentally friendly because it can be produced domestically from several sources and produces no air pollutants or greenhouse gases. Hydrogen-powered vehicles, also referred to as fuel cell vehicles, are currently very expensive and are not widely produced, thus at present they are not a viable alternative, however as the technology continues to develop we will certainly begin seeing more use of hydrogen as a viable fuel source.

As noted with many of these fuels, practicality, most notably the availability and expense of alternative fueling stations is often one of the biggest disadvantages at present. To help with this, the U.S. Department of Energy provides an Alternative Fuel Station Locator to assist you in exploring your options.