ALTERNATIVE FUELS
Alternative Fuels
Alternative fuels are derived from sources other than petroleum and are key in the economic and environmental future of the United States. These fuels are produced domestically, reducing dependence on imported oil, and some are derived from renewable sources. In most cases, they produce less pollution than gasoline or diesel, making them a crucial piece to climate action.
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Renewable Diesel
Renewable diesel is a broad class of fuels derived from biomass feedstocks including oils or animal fats that are processed in the same fashion as traditional petroleum-based diesel. Renewable diesel offers several benefits over biodiesel including reduced waste and by-products, higher energy density, and improved cold flow properties. Renewable diesel can be used exactly like petroleum diesel with no special logistics or blending limitations. Renewable diesel has major benefits over petroleum and biodiesel in areas of greenhouse gas emission and air pollution reductions as well as reduced equipment maintenance.
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Biodiesel
Biodiesel is a renewable, biodegradable fuel manufactured domestically from vegetable oils, animal fats, or recycled restaurant grease. It is a cleaner-burning replacement for petroleum diesel fuel. Biodiesel meets both the biomass-based diesel and overall advanced biofuel requirement of the Renewable Fuel Standard. Biodiesel is a liquid fuel often referred to as B100 or neat biodiesel in its pure, unblended form. Like petroleum diesel, biodiesel is used to fuel compression-ignition engines.
Ethanol
Ethanol is a renewable fuel made from various plant materials collectively known as "biomass". Ethanol has a higher octane number than gasoline, providing premium blending properties. Although Ethanol contains less energy per gallon than gasoline, ethanol has immense potential to reduce greenhouse emissions. To date, ethanol has generated 35 percent of California's greenhouse gas savings.
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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 oil, coal, nuclear energy, hydropower, natural gas, wind energy, solar energy, and stored hydrogen. Plug-in vehicles are capable of drawing electricity from off-board electrical power sources (generally the electricity grid) and storing it in batteries. Though not yet widely available, fuel cell vehicles use hydrogen to generate electricity onboard the vehicle
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Natural Gas
Natural gas is an odorless, gaseous mixture of hydrocarbons—predominantly methane (CH4). It accounts for about a quarter of the energy used in the United States. About one-third goes to residential and commercial uses, such as heating and cooking; one-third to industrial uses; and one-third to electric power production. Although natural gas is a proven, reliable alternative fuel that has long been used to power natural gas vehicles, only about one-tenth of 1% is used for transportation fuel. The vast majority of natural gas in the United States is considered a fossil fuel because it is made from sources formed over millions of years by the action of heat and pressure on organic materials. Alternatively, renewable natural gas (RNG), also known as biomethane, is produced from organic materials—such as waste from landfills and livestock—through anaerobic digestion. RNG qualifies as an advanced biofuel under the Renewable Fuel Standard.
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Propane
Also known as liquefied petroleum gas (LPG), propane is a domestically produced, well-established fuel. Using propane as a vehicle fuel increases energy security, provides convenience and performance benefits, and improves public health and the environment. It is the world's third most common transportation fuel and is considered an alternative fuel under the Energy Policy Act of 1992. Propane is stored onboard a vehicle in a tank pressurized to about 150 pounds per square inch—about twice the pressure of an inflated truck tire. Under this pressure, propane becomes a liquid with an energy density 270 times greater than its gaseous form. Propane has a higher octane rating than gasoline, which prevents engine knocking. However, it has a lower British thermal unit (Btu) rating than gasoline, so it takes more fuel to drive the same distance.