Study Contents

Peer Review Board
Executive Summary
Benefits of Natural Gas
Consumer Use
Commercial Markets
Industrial Markets
Electric Generation
Natural Gas Vehicles
The Supply Challenge
Delivery System

Additional Information

PowerPoint Presentation
Key Findings
Charts & Graphs
New Technologies
Government Energy Sites
Energy Information Sources


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Natural Gas Vehicles

Natural gas vehicles lead the accelerated projection's transportation growth. Gas consumption in the transportation sector increases from 1.1 quads in the current projection to 2.8 quads in the accelerated scenario. The lion's share of the growth, more than 1.5 quads, is attributable to natural gas vehicles (NGVs)-transit buses, trucks, vans and cars. Gas used to power the compressors that move gas through transmission and distribution lines increases to 1 quad in 2020, up modestly from 0.7 quads today. The accelerated projection also includes a small amount of gas used by railroads in the form of liquefied gas.

About 80,000 NGVs are operating in the United States today, dwarfed by more than 200 million gasoline and diesel vehicles. Most NGVs are fueled at some 1,225 compressed natural gas stations throughout the United States, a number that has increased four-fold since 1991. NGVs are the most commercially advanced of the alternatively fueled vehicles-methanol, ethanol, propane and electricity.

Fleet vehicles in areas with air quality concerns offer the most promise. The benefits of NGVs are most pronounced in congested urban areas that have air quality concerns, and federal, state and local organizations have recognized the potential benefits of NGVs in these areas. Promotional federal initiatives include the Clean Air Act, the Clean Cities Program, the Congestion Mitigation Air Quality Program, the Energy Policy Act and the Advanced Natural Gas Vehicle Program.

A number of factors make fleet vehicles — buses, taxis, delivery vehicles — the prime target for natural gas. Because natural gas generally costs less than gasoline, these high-mileage vehicles can realize large savings in fuel costs. Also, fleet vehicles tend to be centrally located. Thus, fleets can locate near refueling stations, or they can install their own facility.

Natural gas vehicles offer tremendous benefits but face serious hurdles. Emissions from cars, trucks and buses are one of our most serious sources of pollution, contributing to urban smog, visibility problems and greenhouse gas emissions. Highway vehicles account for roughly one-third of all carbon dioxide and nitrogen oxides emissions, and half of all carbon monoxide emissions. Using natural gas rather than gasoline can produce major reductions in a number of vehicular emissions. In addition to being cleaner than conventional vehicles, NGVs reduce the nation's extreme dependence on imported oil, and the fuel cost is generally less than the cost of gasoline or diesel fuel.

Despite these benefits and the fact that a survey of fleet operators by the Natural Gas Vehicle Coalition showed that NGVs are their favorite type of alternatively fueled vehicle, market growth for these vehicles has not been dramatic. The primary obstacle is that vehicle production levels are limited, making the purchase price of an NGV higher than the price of a comparable conventionally fueled vehicle. Even for high-mileage vehicles, it is difficult to offset the extra thousands of dollars on an NGV's price tag with the savings in fuel costs of 10 to 20 cents per gallon. Once the demand for NGVs reaches a level that can sustain full production, prices will fall. Currently, the natural gas fueling infrastructure also is limited, but the fueling infrastructure will expand as NGVs gain in popularity.

Natural gas can be used in a compressed or liquefied form to fuel vehicles. NGVs can use either compressed or liquefied natural gas. Natural gas can be compressed at high pressure-up to 3,600 pounds per square inch-and stored in a high-pressure cylinder in the trunk or under the vehicle. Alternatively, natural gas can be cooled to -260oF at which point it is liquefied and can be stored in insulated tanks. In each method, the fuel reaches the engine in a gaseous state. The liquefied natural gas option offers an advantage in that it allows more energy storage per unit of space—600 times more natural gas can be stored in liquefied form. Thus, less room is required of the trunk or other tank area, and driving range can effectively be increased.

Technological focus will be on purchase price and driving range. NGVs have made numerous technological advances during the past decade. The units available today are clean, safe and efficient vehicles that perform much the same as gasoline vehicles. However, a few further technological advances could greatly improve public acceptance.

Experts are working to reduce the purchase price of NGVs, to expand their driving range without sacrificing trunk or other usable space, and to take full advantage of the energy efficiency and environmentally friendly characteristics of natural gas. Finally, a simplified process that converts gas to a liquid, the "syntroleum process," is expected to be commercially viable by 2005. Successful introduction of a viable gas-to-liquid technology would provide significant incentive for using natural gas as transportation fuel.

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