It is undeniable that we are seeing a huge shift away from traditional fossil fuels. As such, numerous alternative fuels are vying for dominance over the transportation sector. Below is a glimpse into the many proposed fuels and their different qualities.
Biodiesel is a type of diesel fuel that is derived from vegetable or animal fats that can be used in regular diesel engines. It can either be used in full concentration or in mixture with traditional diesel. Mixing diesel with biodiesel allows the fuel blend to be used safely in any diesel engine, thus increasing the utility of biodiesel and requiring minimal modifications to engines. Therefore, it is unlikely that biodiesel will completely replace the role of petroleum in transportation. Pure biodiesel is known to degrade engine components faster than normal diesel, and it also clogs fuel filters more rapidly.
Ethanol is widely used around the world as a fuel additive. The most commonly used mixture in the US, E10, features 10% ethanol and 90% gasoline. The vast majority of ethanol used in the United States is derived from corn. Several studies have demonstrated that ethanol blends are able to reduce greenhouse gas emissions. However, ethanol exhaust creates significantly more ozone and local pollution than traditional gasoline, which is problematic for cities that already struggle with air quality. While we may not see it used in its pure form, we likely will continue to use ethanol as an additive to gasoline.
One surprising alternative fuel that has emerged recently is vegetable oil. Diesel engines can be modified to be able to use straight vegetable oil, and vegetable oil can also be used as an additive to traditional diesel fuel. In order to use vegetable oil, the engine must be modified to heat the oil enough to reduce the viscosity of the oil. Otherwise, the oil would cause lasting harm to the engine. The engine starts by using diesel until it is hot enough and then switches to using vegetable oil. While this is intriguing, you probably won’t see this on a mass scale. It costs more than normal gasoline and requires complex modifications beyond the scope of a regular consumer.
If you’ve seen a Tesla or a Nissan LEAF on the road, you’ve seen an electric car. Electric cars are surging in popularity due to advances in fuel cell technology and low electricity prices. They work by converting energy stored in lithium-ion fuel cells into raw power used to drive an engine. While they are able to get instant torque, electric vehicles are limited by range and the heavy battery packs they are required to carry. We will likely see continued growth of electric vehicles with advances in technology that will drive down costs, so it is very likely that electric vehicles will comprise an increasingly large share of transportation around the world.
Hydrogen offers an emissions-free alternative to traditional fuel. In a hydrogen-powered engine, pure hydrogen gas is burned and combines with oxygen in the air to create water molecules. This reaction creates energy which is used to power the car. While it would work in theory and is used as rocket fuel, it is an impractical fuel for mass transportation. The process of creating hydrogen gas is energy-intensive and inefficient, and the gas itself is difficult to store. This makes it impractical for widespread usage.
Of course, there’s no silver bullet. We will likely continue to rely on a variety of fuels to meet the growing demands of the transportation sector. Nevertheless, the most likely alternative to traditional fuel usage is electricity because of cheap electrical costs, advances in battery and energy production, and permissive regulatory environments. So keep an eye out for electric vehicles on the road – there may soon be more than you’d think.