More than a dozen alternative fuels are in production or under development for use in alternative fuel vehicles and advanced technology vehicles. Government and private-sector fleets are the primary users for most of these fuels and vehicles, but individual consumers are increasingly interested in them. Using alternative fuels including electricity and advanced vehicles instead of conventional fuels and vehicles helps the United States conserve petroleum and lower vehicle emissions.
BIODIESEL
Biodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant grease for use in diesel vehicles or any equipment that operates on diesel fuel. Biodiesel’s physical properties are similar to those of petroleum diesel.
ELECTRICITY
Electricity is considered an alternative fuel under the Energy Policy Act of 1992. Electricity can be produced from a variety of energy sources, including natural gas, coal, nuclear energy, wind energy, hydropower, and solar energy. This electricity can be stored in batteries or used to produce hydrogen. Electric vehicles (EVs)—the collective term for plug-in hybrid electric vehicles.
ETHANOL
Ethanol is a renewable fuel made from corn and other plant materials. Ethanol use is widespread, and more than 98% of gasoline in the U.S. contains some ethanol. The most common blend of ethanol is E10 (10% ethanol, 90% gasoline). Ethanol is also available as E85 (or flex fuel)—a high-level ethanol blend containing 51% to 83% ethanol, depending on geography and season—for use in flexible fuel vehicles.
HYDROGEN
Hydrogen, when used in a fuel cell to provide electricity, is a zero tailpipe emissions alternative fuel produced from diverse energy sources. Currently, drivers of light-duty fuel cell electric vehicles (FCEVs) can fuel up at retail stations in less than 5 minutes and obtain a driving range of more than 300 miles.
NATURAL GAS
Natural gas, a domestically produced gaseous fuel, is readily available through the existing natural gas distribution system. Whether produced via conventional or renewable methods, this clean-burning alternative fuel must be compressed or liquefied for use in vehicles.
PROPANE
Propane, also known as liquefied petroleum gas (LPG) or propane autogas, has been used worldwide as a vehicle fuel for decades. It is stored as a liquid, and propane fueling infrastructure is widespread.
Idle Reduction Technologies
Idle reduction describes technologies and practices that reduce the amount of time an engine idles. Idling wastes fuel and increases engine wear, so small changes in idling time can lead to noticeable benefits, including fuel savings and a reduction in pollution, greenhouse gas emissions, noise, and engine wear.
Idle reduction technology allows engine operators to refrain from long-duration idling of the main propulsion engine by using an alternative technology. Heavy-duty truck drivers can choose from a variety of equipment to reduce idle time and save fuel.
What are the benefits of idle reduction?
Reducing vehicle idling time saves fuel and money, cuts pollution and greenhouse gas emissions, and contributes to U.S. energy security. Decreasing idle time can also reduce engine wear and associated maintenance costs, especially for heavy-duty trucks.
Saving Fuel and Money
Argonne National Laboratory estimates that more than one million long-haul heavy-duty trucks idle during required rest stops. As the trucks idle, they consume more than one billion gallons of fuel per year. In addition, thousands of work trucks idle to support jobs daily, and millions of passenger cars idle waiting in traffic or pickup situations. Accounting for all road vehicles, from passenger cars to heavy-duty trucks, Argonne estimates that more than 6 billion gallons of gasoline and diesel combined are lost to idling every year. Even when fuel prices are as low as $2 per gallon, that wasted fuel translates into more than $11 billion annually—much of which could be saved with idle reduction technologies.
Cutting Harmful Emissions
Idle reduction strategies can reduce emissions of greenhouse gases and other harmful pollutants. Idle reduction strategies also reduce noise pollution.
Increasing Energy Security
The United States remained a net exporter of petroleum in 2021 with exports surpassing imports, although imports of 8.47 million barrels per day remained an important part of balancing supply and demand for domestic and international markets. Overall, the transportation sector accounts for approximately 30% of total U.S. energy needs and 70% of U.S. petroleum consumption. Using idle reduction strategies to reduce petroleum consumption strengthens national energy security and reduces transportation energy costs for businesses and consumers.
Complying with Laws and Ordinances
Many states have idle reduction laws and incentives. In addition, many counties and municipalities have enacted idling restrictions. View Clean Cities IdleBase to access a database covering idling laws, from the local level to the state level spanning all types of on-road vehicles. For information specific to heavy-duty trucks, see the American Transportation Research Institute’s Idling Regulations Compendium.
In some areas, heavy-duty trucks and trains are required to limit noise at night. By adopting idle reduction strategies and technologies, vehicle operators can comply with noise standards.
Idle Reduction Equipment
The U.S. Environmental Protection Agency’s (EPA) SmartWay Program and the U.S. Department of Energy (DOE) have evaluated the fuel-saving benefits of various idle reduction technologies. Both agencies provide information about grant funding that may be available for installation of qualifying equipment. EPA’s SmartWay Program offers a list of Verified Idle Reduction Technologies. These technologies include: