Top 10 Alternative Fuels Currently in Use

Every summer, it happens, and nobody enjoys it. We’re not referring to uneven tans or early morning lawn mowing. Instead, we’re talking about the seasonal surge in fuel costs. The summer of 2008 was particularly harsh, with average gas prices soaring above $4 per gallon nationwide, forcing many to check their bank accounts before filling up.

With the 2008 gas price crisis still vivid and new increases on the horizon, it’s natural to explore alternatives to traditional gasoline vehicles. Fortunately, numerous options exist, and many are already available on the roads or in showrooms. While some alternatives may take time to become mainstream, here’s a look at the top 10 alternative fuels currently in use.

10: Hydrogen

While the idea of using hydrogen to power your car might evoke thoughts of the Hindenburg disaster, it’s actually a very safe option. Hydrogen can fuel two distinct types of vehicles: those with fuel cell technology and those with internal combustion engines modified to run on hydrogen instead of gasoline.

In fuel-cell vehicles, hydrogen generates electricity to power electric motors. Instead of relying solely on batteries, these cars use fuel cells to produce their own electricity. Through a chemical reaction in the fuel cell, hydrogen and oxygen combine to create electricity, with water vapor as the only byproduct. The Honda FCX Clarity employs this technology and is currently available for lease in southern California.

In a hydrogen combustion engine, vehicles operate similarly to gasoline-powered cars but use hydrogen as the fuel source instead of gasoline. Unlike traditional cars that emit harmful CO2, hydrogen cars release only water vapor. Many automakers are currently experimenting with hydrogen vehicles. The BMW Hydrogen 7 is one of the most notable examples, with several leased to prominent figures in Germany and the U.S. Some studies even suggest that the vehicle can purify the surrounding air [source: U.S. News Rankings and Reviews].

The limited adoption of hydrogen cars is primarily due to the lack of a widespread fueling station infrastructure. However, our next alternative fuel is far more accessible—in fact, you’re likely using it at this very moment.

9: Electricity

While it might seem that electric cars have taken a long time to develop, the reality is that some of the earliest vehicles relied on electric motors. However, it’s only in recent years that advancements have made electric cars a practical option for daily transportation.

So, what’s been the delay? The main challenge has been battery technology. Propelling a car requires significant power, and maintaining high speeds over long distances can rapidly deplete an electric car’s batteries. In the past, electric vehicles had limited range, and recharging their batteries could take an impractical amount of time.

Thanks to advancements in battery technology, automakers are now overcoming these obstacles. Modern batteries, specifically lithium-ion batteries, are the same type used in cell phones and laptops. They charge faster and hold their charge longer. Vehicles like the Tesla Roadster leverage these batteries to deliver high-performance electric driving. Upcoming models, such as the Chevy Volt, combine these batteries with internal combustion engines to create extended-range electric vehicles. These cars can be charged by plugging into a standard wall outlet, and when the battery runs low, an onboard gasoline generator kicks in to recharge the batteries and extend the vehicle’s range.

8: Biodiesel

While a low-fat diet with minimal fried foods is beneficial for your health, the same principle doesn’t necessarily apply to your vehicle.

Biodiesel is a fuel derived from cooking oil and grease. Any diesel engine can run on it—but don’t think you can pour leftover fast-food grease directly into your tank. The oil and grease must undergo a chemical conversion process to become usable biodiesel.

This process can even be done at home. Many biodiesel enthusiasts produce their own fuel using used cooking oil from nearby restaurants. However, there are risks involved. Mistakes in the process can harm your vehicle, your home, or even yourself. It’s wise to learn from someone experienced before attempting to make biodiesel on your own.

Biodiesel enthusiasts are passionate about its benefits. Not only is it cheaper and cleaner than traditional diesel, but it also leaves your car smelling like french fries. Seriously! Just ensure you and your vehicle are prepared before diving into homemade biodiesel production.

7: Ethanol

Now that you know cars can run on fry grease, what if you prefer a healthier option and don’t want your vehicle smelling like fries? What alternatives are available? Well, how about ensuring your car gets its daily dose of vegetables too?

Ethanol is a growing alternative fuel. It’s frequently blended with gasoline during summer to reduce emissions. Ethanol, a type of alcohol (not for consumption), is produced from plant materials. In the U.S., it’s typically made from corn, while countries like Brazil use sugar cane.

Many automakers provide vehicles with flex-fuel engines, capable of running on either standard gasoline or E85 ethanol, a blend of 15% gasoline and 85% ethanol. Ethanol is often praised as a solution to reduce America’s reliance on foreign oil. Since it can be domestically produced and isn’t a finite resource like oil, it offers a sustainable alternative. However, producing ethanol requires significant energy, and critics argue that farmers might prioritize growing crops for ethanol over food, potentially driving up food prices.

Despite these concerns, ethanol provides numerous advantages as an alternative fuel, and the number of ethanol fueling stations continues to grow.

6: Liquefied Natural Gas

Continuing the culinary theme, another alternative fuel already in use is something you might find in your kitchen. Unlike ethanol or biodiesel, it’s not made from edible ingredients, but it’s a favorite among professional chefs: natural gas.

Natural gas, a fossil fuel, is extracted from underground rock layers. Like oil, it’s drilled, but the U.S. has abundant reserves, and it burns cleaner than oil or gasoline. The natural gas used for cooking and heating is in a low-pressure form, remaining gaseous and releasing less energy when burned.

When natural gas is cooled, it becomes liquefied, significantly increasing its energy density. Liquefied natural gas (LNG) releases far more energy when burned. While low-pressure natural gas is great for heating soup, LNG can power heavy machinery, such as trucks, making it ideal for long-distance, heavy-duty transportation.

5: Liquefied Petroleum Gas

If you’ve attended a barbecue recently, you’ve likely encountered our next alternative fuel: liquefied petroleum gas, or LP gas. Still unsure? Think propane grills—that’s LP gas in action.

Propane is the popular term for liquefied petroleum gas, though it’s not entirely accurate. LP gas is a low-pressure hydrocarbon gas, primarily composed of propane but including other hydrocarbon gases. It’s stored under pressure to maintain its liquid state, similar to liquefied natural gas, making it energy-dense and ideal for powering vehicles.

LP gas fuels vehicles through specially designed internal combustion engines. While it’s not widely used for cars in the U.S., it makes up 10% of automotive fuel in the Netherlands, and many other countries have also adopted it [source: California Energy Commission].

4: Compressed Natural Gas

Imagine if, instead of visiting a gas station to refuel your car, you had a fuel line connected directly to your home, available whenever needed.

With a compressed natural gas (CNG) vehicle, this is possible. CNG is the same fuel used for cooking and heating in homes, delivered via gas lines. For CNG vehicles, the gas is stored in high-pressure cylinders. However, fueling a CNG car requires more than just connecting to a household gas line—you’ll need a home fueling station capable of compressing the gas. The compressed gas is then stored in the car’s fuel tanks, as CNG occupies more space than gasoline.

Honda launched the Honda Civic GX in 1998, a standard Civic model powered by compressed natural gas. Since CNG is cheaper and cleaner-burning than gasoline, these vehicles could become more popular, especially if the cost of installing a home fueling station is offset by fuel savings. However, a major drawback is the lack of a nationwide CNG fueling network, meaning running out of fuel far from home could leave you stranded.

3: Compressed Air

Air is abundant, so why not harness it to power vehicles? Compressed air cars do exactly that.

In these vehicles, air is stored in high-pressure tubes. Unlike traditional engines that mix air with gasoline or diesel and ignite it with a spark to generate power, compressed-air engines use the expansion of released air from the tubes to drive the pistons.

Compressed-air vehicles don’t rely solely on air. They also feature electric motors to compress air into high-pressure tubes. However, they aren’t classified as fully electric cars because the motors don’t directly drive the wheels. These motors are smaller than those in traditional electric vehicles, where their primary role is to power the wheels. Like electric cars, compressed-air cars require charging, but due to the lower energy consumption of their motors, charging times are significantly shorter.

2: Liquid Nitrogen

Liquid nitrogen serves as another alternative fuel. Like hydrogen, nitrogen is plentiful in the atmosphere. Similar to hydrogen-powered vehicles, nitrogen cars produce fewer harmful emissions compared to gasoline or diesel. However, while hydrogen is used in fuel cell vehicles and hydrogen-combustion engines, liquid nitrogen cars operate on an entirely different type of engine.

A liquid nitrogen car operates with an engine similar to that of a compressed-air car. The nitrogen is stored in a liquid state by keeping it cold. To power the vehicle, the nitrogen is released into the engine, where it heats up and expands, generating energy. Unlike gasoline or diesel engines that rely on combustion to move pistons, a liquid nitrogen engine uses the expansion of nitrogen to drive turbines.

While liquid nitrogen is a clean and efficient fuel source, it faces the same challenges as many alternative fuels: there’s currently no nationwide network of fueling stations to make it accessible to consumers.

1: Coal

The last alternative fuel on our list might come as a surprise. How can coal possibly power cars?

Technically, coal is an indirect and relatively new alternative fuel for vehicles. As electric cars, plug-in hybrids, and extended-range electric vehicles grow in popularity, coal will play a role in fueling them. No, you won’t need to shovel coal into incinerators—that’s not how it works.

Electric vehicles, for the most part, don’t generate their own electricity. They store energy in their batteries, which are charged via standard wall outlets. These outlets draw power from electricity plants, many of which burn coal. In fact, 50% of U.S. electricity comes from coal-fired plants [source: PBS.org]. This means that, when you trace the energy chain, many electric cars are essentially coal-powered.

While coal shares some disadvantages with gasoline, it also offers benefits. On a per-mile basis, electricity from coal is cheaper than gasoline. Additionally, the U.S. has abundant coal reserves, reducing the risk of supply disruptions due to international relations. Moreover, those who source electricity from hydroelectric or nuclear power plants can charge their electric cars without contributing to coal emissions.

However, the reality that some of the most anticipated eco-friendly cars may rely on a less-than-clean energy source highlights a key truth: in the energy world, there’s no such thing as a free lunch.