Produced domestically from vegetable oils, animal fats, or recycled restaurant grease, biodiesel is a cleaner and more secure source of energy than standard oil. Though biodiesel blends can vary, the common blend of B100 reduces emissions 74% (Argonne Laboratory). This is because the emissions are offset through the CO2 absorption of the plants grown for production. If spilled, pure biodiesel poses far less threats to the natural environment than petroleum. It also raises the cetane number of fuel and increases fuel lubricity.
Electricity is used to power plug-in electric vehicles (PEVs) directly from the grid. Hybrid vehicles still use liquid fuels, like gasoline, but have smaller batteries than full electric vehicles that use energy from braking to charge them, which in turn helps vehicle mileage. There are many fully electric models of cars available now, with ranges anywhere from 80 miles to 370 miles. There are also a couple of different charging systems, each of which has a different voltage that affects charging time. You can charge at home, on the road, or at some businesses and communal areas as the infrastructure is rapidly expanding. There are many funding opportunities and incentives associated with electric vehicles, maintenance costs are often minimal, and fuel costs are dramatically reduced. Electric vehicles produce no tailpipe emissions, though there may be emissions associated with the energy production from the grid.
Propane (C3H8) has been used for decades and is stored under pressure in a tank as a an odorless and colorless liquid. As the pressure is released, the liquid propane is vaporized and it turns into gas that is then used in combustion. It has a high octane rating and if spilled, does not pose any great threats. It is mostly used to power amenities in homes and is formed as a by-product of crude oil refinement and natural gas production. It is the third most common fuel type in the world and is relatively low cost. There are light, medium, and heavy duty vehicles available ready to accommodate propane. It has low maintenance costs, typically costs less per gallon than gasoline, and provides a comparable driving range to conventionally fueled vehicles.
A lesser known alternative fuel, hydrogen, has a diverse range of sources. There are a limited number of hydrogen powered light duty vehicles and vehicles for fleets. Hydrogen is very abundant in our natural environment, but the obstacles surface when trying to extract it from its source whether it’s from water or other organic materials. Hydrogen can power fuel cells with zero emissions, has high efficiency, can be filled quickly, and can be produced domestically.
For reference, the energy in 2.2 pounds of hydrogen gas is about the same as the energy in 6.2 pounds of gasoline. Though the production of hydrogen entails emissions, these can be reduced through renewable energy options such as solar, wind, and more.
Natural gas, mostly consisting of methane, is widely used in energy production but not as often for powering vehicles. While some natural gas is considered a fossil fuel as it comes from sources thousands of years old, renewable natural gas (RNG) can come from organic materials from landfills, livestock and more, and is seen as much more sustainable than conventional natural gas. Compressed natural gas (CNG) and liquified natural gas (LNG) are available for commercial use, are domestically produced, and are relatively cheap. Though, liquified natural gas has high production costs, so it is less frequently utilized. A CNG-powered vehicle gets about the same fuel economy as a conventional gasoline vehicle on a GGE basis.