The Top Three Commonly Used Alternative Fuels Today
The top three commonly used alternative fuels are ethanol (bioethanol blended into gasoline), biodiesel and renewable diesel (biomass-based diesel replacements), and electricity for battery electric and plug-in hybrid vehicles. These dominate due to widespread blending mandates, compatibility with existing vehicles and infrastructure, and rapid growth in electric mobility. Below, we explain how these fuels are used, why they lead the market, and what to know about their performance and outlook.
Contents
How “alternative fuels” are defined and why these three lead
Alternative fuels are energy sources used in transport that displace conventional petroleum gasoline and diesel. Definitions vary by country, but most agencies (such as the U.S. Department of Energy and the International Energy Agency) include liquid biofuels (ethanol, biodiesel, renewable diesel), electricity, compressed/liquefied natural gas, propane (LPG), and hydrogen. Among these, ethanol, biomass-based diesel, and electricity are the most widely used today by volume or vehicle adoption and have the broadest policy support and infrastructure.
Why these three dominate today
The following points summarize the main reasons ethanol, biodiesel/renewable diesel, and electricity stand out in current transport energy use.
- Scale through blending and mandates: Ethanol and biodiesel are blended into most gasoline and diesel in major markets (e.g., E10 in the United States, E5–E10 in Europe, E27 in Brazil; B5–B20 diesel blends are common), ensuring mass adoption through existing fuel networks.
- Compatibility and drop-in options: Biodiesel blends work in most diesel engines; renewable diesel (HVO) is a true drop-in. Ethanol up to E10 works with almost all gasoline vehicles. This lowers barriers to use.
- Rapid growth in electrification: Tens of millions of electric vehicles are now on the road worldwide, with EVs approaching one-fifth of global new car sales in 2023 and growing again in 2024, making electricity an increasingly significant transport “fuel.”
Together, these dynamics explain their prevalence: biofuels leverage existing engines and distribution, while electricity is scaling quickly with the transition to zero-tailpipe-emission vehicles.
Profiles of the top three alternative fuels
Ethanol (bioethanol blended into gasoline)
Ethanol is an alcohol fuel produced primarily from sugarcane, corn, or other starches and sugars, with cellulosic (waste and residue) pathways emerging. It is commonly blended into gasoline to increase octane and reduce petroleum use. Typical blends include E10 (about 10% ethanol, widely used in the United States and many other countries), E5–E10 (Europe, parts of Asia), and higher blends like E15/E85 for compatible or flex-fuel vehicles. Brazil regularly uses E27 and pure hydrous ethanol in flex-fuel cars.
By scale, ethanol is the most widely used alternative fuel globally, with annual production on the order of roughly 100 billion liters. Lifecycle greenhouse gas (GHG) reductions vary by feedstock and pathway: sugarcane ethanol commonly achieves around 50–70% reductions versus gasoline; corn ethanol in modern facilities can deliver roughly 20–50% reductions; cellulosic ethanol can surpass 70–80% when fully commercialized. Infrastructure needs are modest at low blends, since ethanol is distributed through existing fuel terminals and retail stations.
Biodiesel and renewable diesel (biomass-based diesel)
Biodiesel (fatty acid methyl esters, or FAME) and renewable diesel (hydrotreated vegetable oil, HVO) are produced from vegetable oils (soy, canola), used cooking oil, animal fats, and other lipids. FAME is typically used in blends such as B5, B10, or B20; renewable diesel is a drop-in fuel chemically similar to petroleum diesel and can be used at any blend level, including RD100, without engine modifications.
Combined global consumption of FAME biodiesel and renewable diesel is on the order of tens of billions of liters annually, with renewable diesel growing fastest in North America and Europe due to favorable policies. Lifecycle GHG reductions range from about 50–80% for biodiesel and roughly 60–90% for renewable diesel, depending on feedstock and process. Biodiesel can face cold-flow limitations at high blends in cold climates, while renewable diesel maintains excellent cold-weather performance and compatibility with modern diesel emissions systems.
Electricity (for battery EVs and plug-in hybrids)
Electricity powers battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs). While it requires purpose-built vehicles and charging infrastructure, electricity has become one of the most consequential petroleum alternatives in light-duty transport. There are now tens of millions of EVs on the road globally; in 2023, electric cars represented around 18% of new car sales worldwide, with further growth through 2024.
Electric vehicles offer zero tailpipe emissions and significantly lower lifecycle GHG emissions in most regions today, with the advantage increasing as grids decarbonize. Total cost of ownership is often favorable due to lower fuel and maintenance costs. Charging options include home Level 2 charging for daily needs and expanding networks of DC fast chargers for longer trips. Grid impacts are manageable with smart charging, and vehicle-to-grid (V2G) pilots are emerging in several markets.
How they compare on key criteria
The following list contrasts the three fuels across practical considerations commonly used by fleets, policymakers, and consumers.
- Compatibility with existing vehicles
- Ethanol: Up to E10 compatible with nearly all gasoline vehicles; higher blends require certified or flex-fuel vehicles.
- Biodiesel/Renewable diesel: B5–B20 usable in most diesel engines; renewable diesel is drop-in (up to 100%).
- Electricity: Requires BEVs/PHEVs; no compatibility with conventional ICE vehicles.
- Infrastructure and deployment speed
- Ethanol and biodiesel: Leverage current liquid fuel logistics and stations; rapid scaling through blending mandates.
- Electricity: Requires build-out of residential, workplace, and public charging; ramping quickly but uneven by region.
- Emissions and air quality
- Ethanol and biodiesel: Significant lifecycle GHG reductions vs. petroleum when responsibly sourced; lower particulate and CO emissions; NOx impacts vary.
- Electricity: Zero tailpipe emissions; lifecycle GHG depends on grid mix but improves as renewables grow.
- Cost and market dynamics
- Ethanol/biodiesel: Costs influenced by feedstock markets and policy credits; typically competitive at blend levels.
- Electricity: Lower per-mile energy cost and maintenance for EVs; vehicle purchase price declining as batteries improve.
Taken together, biofuels win on immediate compatibility and scale through blending, while electricity leads on tailpipe emissions, long-term decarbonization potential, and operational savings as infrastructure expands.
Where other alternatives fit
Several other alternative fuels are meaningful in specific markets and segments, even if they are not among the top three by widespread use.
- Propane (LPG/autogas): Popular for fleets and taxis in countries like South Korea and Turkey; offers lower emissions than gasoline and straightforward refueling.
- Natural gas (CNG/LNG): Used in buses, trucks, and taxis in parts of Asia, Europe, and the Americas; delivers lower tailpipe pollutants and can be renewable when produced as biomethane (RNG).
- Hydrogen: Growing interest for heavy-duty, long-range, and fast-refueling applications; limited but expanding infrastructure, with the cleanest benefits when produced from low-carbon sources.
These fuels can be optimal for particular duty cycles, geographies, or policy environments, complementing the leading trio in the broader transition away from petroleum.
Outlook for 2025 and beyond
Biofuel blending is expected to remain a cornerstone of near-term decarbonization, with renewable diesel capacity expanding and advanced cellulosic pathways progressing. Electric mobility is set to continue strong growth as battery costs fall, charging networks densify, and more models enter the market, including commercial vehicles. Over time, electricity’s share of transport energy is likely to rise markedly, while sustainable feedstocks guide the scale and sustainability of liquid biofuels. Regional policy—such as clean fuel standards, emissions rules, and renewable targets—will shape the exact mix.
Summary
The three most commonly used alternative fuels are ethanol, biodiesel/renewable diesel, and electricity. Ethanol and biomass-based diesel dominate today thanks to blending into existing fuels and compatibility with current vehicles and infrastructure, delivering meaningful GHG reductions. Electricity is rapidly scaling with the global rise of EVs, offering zero tailpipe emissions and improving lifecycle performance as grids decarbonize. Other options—propane, natural gas, and hydrogen—play important roles in specific regions and vehicle segments, rounding out the alternative fuel landscape.
What are the three most commonly used fuels?
Fuels are materials that produce energy when burned or go through other chemical changes. Gasoline, diesel, and kerosene are three common fuels, each suited for different applications. They are crucial for things like transportation, electricity generation, and running factories.
What are the top 3 most used renewable energy sources?
Globally we see that hydropower is by far the largest modern renewable source. However, we also see wind and solar power both growing rapidly.
What are three commonly used alternative fuels?
Three commonly used alternative fuels are Electricity for electric vehicles, Ethanol for blended gasoline and flex-fuel vehicles, and Biodiesel for diesel engines. Other popular options include Compressed Natural Gas (CNG), Liquefied Petroleum Gas (LPG or Propane), and Hydrogen, which are used in vehicles designed to run on these different energy sources.
Here’s a brief overview of each:
- Electricity
- How it works: Electricity powers electric vehicles (EVs) by storing energy in batteries, which are then recharged at home or at public charging stations.
- Why it’s an alternative: It produces zero tailpipe emissions, reducing air pollution and reliance on fossil fuels, and can be generated from various renewable sources like solar and wind power.
- Ethanol
- How it works: This alcohol-based fuel is primarily made from corn and other crops, then blended with gasoline to create fuel for flex-fuel vehicles or used in higher blends like E85.
- Why it’s an alternative: Ethanol is a renewable fuel that has a lower carbon footprint than traditional gasoline and can be produced domestically, which reduces dependence on foreign oil.
- Biodiesel
- How it works: Derived from vegetable oils and animal fats, biodiesel can be used in diesel engines either in blends with petroleum diesel or as a standalone fuel.
- Why it’s an alternative: It offers a renewable option for diesel vehicles, burning cleaner than petroleum diesel and having a lower overall carbon footprint.
What is the best alternative fuel?
When it comes to looking to the energy source that will replace fossil fuels, there are no shortage of options. Solar power, wind energy, ethanol and biofuels are typically the most widely cited contenders to replace petroleum-based combustion engines and coal-fired power plants.
