Alternative fuel options: what’s available now and what’s coming next

Alternative fuel options today include electricity (battery-electric), hydrogen (fuel cells or combustion), biofuels (ethanol, biodiesel, renewable diesel, sustainable aviation fuel), natural gas (CNG/LNG) and renewable natural gas, propane (LPG), synthetic e-fuels (power-to-liquids and power-to-gas), and emerging choices such as methanol, ammonia, and dimethyl ether. These fuels target different vehicles and use cases, offering pathways to cut petroleum use and greenhouse gas emissions with varying trade-offs in cost, infrastructure, and performance.

The main categories of alternative fuels

Transportation energy is diversifying. The following categories capture the principal alternatives to conventional gasoline, diesel, and heavy fuel oil, grouped by how they’re produced and used.

• Electricity (battery-electric vehicles and plug-in hybrids)
• Hydrogen (fuel cells; limited use in hydrogen combustion engines)
• Biofuels (ethanol, biodiesel/FAME, renewable diesel/HVO, sustainable aviation fuel, biomethanol, renewable propane)
• Natural gas family (CNG/LNG) and renewable natural gas (RNG/biomethane)
• Propane autogas (LPG), including renewable propane
• Synthetic e-fuels made with green hydrogen and captured CO₂ (e-diesel, e-kerosene, e-methanol, e-methane)
• Emerging maritime/heavy-duty options (methanol, ammonia, dimethyl ether)

Each category differs in maturity, scalability, and emissions profile; in practice, the “right” fuel depends on duty cycle, infrastructure, and policy incentives.

Electricity (battery-electric vehicles)

Battery-electric vehicles (BEVs) use grid electricity stored in batteries to power motors. They dominate the light-duty decarbonization pathway and are expanding into buses, delivery vans, and short-haul trucks as batteries improve and charging networks grow.

Advantages

BEVs bring several technical and operational benefits relative to combustion engines.

• High efficiency: roughly 60–80% of grid electricity becomes motion, versus about 20–35% for gasoline/diesel drivetrains.
• Zero tailpipe emissions: no local NOx/PM; lifecycle emissions depend on the electricity mix, which continues to decarbonize in many regions.
• Lower maintenance: fewer moving parts and no oil changes reduce service needs.
• Regenerative braking: recovers energy in stop-and-go duty cycles (e.g., urban delivery and transit).

These attributes translate to strong total-cost-of-ownership (TCO) in many light- and medium-duty applications, especially with high annual mileage.

Limitations and infrastructure

BEVs also face constraints that planners must consider.

• Charging time and access: fast charging mitigates downtime but requires high-power infrastructure and grid capacity.
• Range variability: cold weather, high speed, heavy loads, and elevation reduce range.
• Upfront cost and battery supply chain: costs have fallen but remain sensitive to mineral prices; recycling and new chemistries are scaling.
• Grid readiness: depot charging may need upgrades; managed charging and on-site storage can help.

These factors are improving with network buildout, battery advancements, and smart charging strategies.

Best-fit applications

Current technology and economics make BEVs particularly compelling in specific segments.

• Passenger cars and SUVs, especially in regions with robust charging networks.
• Urban buses and school buses with predictable routes and depot charging.
• Last-mile delivery vans and medium-duty trucks with return-to-base operations.
• Two- and three-wheelers, which electrify rapidly in Asia, Africa, and Latin America.
• Short-haul and regional heavy trucks on fixed corridors with megawatt charging emerging.

As batteries and charging improve, BEVs are expanding into heavier and longer-range use cases.

Hydrogen

Hydrogen can power fuel-cell electric vehicles (FCEVs) or, less commonly, internal combustion engines designed for H₂. Its value lies in quick refueling and long range for high-utilization, heavy-duty duty cycles, but end-to-end efficiency and infrastructure costs are challenges.

Production pathways

Hydrogen’s climate impact depends on how it’s made.

• Green hydrogen: electrolysis using renewable electricity; lowest lifecycle emissions when powered by clean grids.
• Blue hydrogen: reforming natural gas with carbon capture and storage (CCS); emissions hinge on capture rates and methane leakage.
• Turquoise hydrogen: methane pyrolysis producing solid carbon; real-world emissions depend on heat source and leakage.
• Nuclear/“pink” hydrogen: electrolysis powered by nuclear energy; low-carbon where available.

Policy incentives (for example, U.S. production tax credits and EU support mechanisms) are accelerating lower-carbon pathways, especially green hydrogen.

Pros and cons

Hydrogen’s strengths and drawbacks vary by application.

• Pros: fast refueling, long range, strong cold-weather performance, and suitability for heavy-duty, rail, and some maritime applications.
• Cons: lower well-to-wheels efficiency than batteries, high station and logistics costs, storage complexity (700 bar or liquid), and sensitivity to methane leakage for fossil-based routes.

Where routes, utilization, and depot-scale fueling align, hydrogen can be competitive despite efficiency penalties.

Applications

Hydrogen is finding traction in niches that value uptime and range.

• Fuel-cell buses and regional/heavy trucks on hub-and-spoke or corridor networks.
• Material-handling and forklifts in warehouses with on-site fueling.
• Passenger and freight trains on non-electrified lines as diesel replacements.
• Maritime pilots (often via ammonia or methanol as carriers) and stationary backup power.

Scaling requires coordinated investments in production, transport, and dispensing infrastructure.

Biofuels

Biofuels are produced from plant matter, waste oils, or biogenic gases. They can often blend with—or fully replace—conventional fuels, enabling near-term emissions cuts without swapping out engines. Sustainability depends on feedstock sourcing, land-use impacts, and processing.

Ethanol

Ethanol is widely used in gasoline blends (E10, E15) to cut carbon intensity and boost octane; flex-fuel vehicles can run on E85. Lifecycle emissions vary by feedstock and farming practices; cellulosic ethanol offers deeper reductions but remains supply-constrained.

Biodiesel and renewable diesel

Biodiesel (FAME) blends into diesel (e.g., B5–B20) and can modestly raise NOx without modern controls. Renewable diesel (HVO) is a “drop-in” fuel—chemically similar to diesel—with higher cetane and better cold-flow performance; it can be used at 100% (RD100) in approved engines and infrastructure.

Sustainable aviation fuel (SAF)

SAF includes multiple pathways (HEFA from waste oils, Fischer–Tropsch from biomass residues/renewable electricity and CO₂, alcohol-to-jet). Commercial flights generally use blends up to 50% today under ASTM D7566; 100% SAF flights have been demonstrated but are not yet routine. Mandates in the EU and incentives in the U.S. are driving scale-up through the 2020s.

Renewable natural gas (RNG)

RNG (biomethane) is produced by upgrading biogas from landfills, wastewater, or manure. Injected into pipelines or used as CNG/LNG, it can deliver substantial lifecycle reductions; some dairy-manure pathways achieve very low or even negative carbon intensity under programs like California’s LCFS.

Pros and cons

Biofuels’ practicality comes with important caveats.

• Pros: drop-in compatibility, immediate fleet emissions cuts, use of waste streams, and applicability to hard-to-electrify sectors (aviation, legacy diesel fleets).
• Cons: limited sustainable feedstocks, potential indirect land-use change, varying air-pollution profiles, and competition with food and ecosystems if poorly managed.

Robust sustainability standards and advanced pathways help maximize climate benefits while minimizing unintended impacts.

Natural gas and propane

Compressed (CNG) and liquefied (LNG) natural gas, as well as propane (LPG), are established alternatives in fleets, with mature engines and fueling. Climate benefits depend on methane leakage control and the use of renewable variants like RNG or renewable propane.

CNG and LNG

CNG suits urban and regional fleets (transit, refuse), while LNG targets longer-haul operations thanks to higher energy density. Relative to diesel, fossil natural gas can reduce CO₂ by roughly 10–20% per unit of work if methane slip is minimized; uncontrolled leakage can negate benefits. RNG can dramatically improve lifecycle performance.

Propane autogas (LPG)

Propane is popular for school buses and medium-duty fleets due to lower NOx/PM than diesel, fast refueling, and cold-weather performance. It’s typically a byproduct of natural gas processing and petroleum refining; renewable propane from biomass or e-fuel pathways is emerging in small volumes.

Pros and cons

The gas family offers practical advantages with clear constraints.

• Pros: mature technology, lower local pollutants than diesel, lower fuel cost volatility in some markets, and quick refueling.
• Cons: methane leakage concerns (for natural gas), modest CO₂ reductions if fossil-based, and infrastructure that may face long-term policy headwinds as zero-emission rules tighten.

Targeted use with tight methane controls and renewable supply can deliver credible benefits in selected fleets.

Synthetic e-fuels (power-to-liquids and power-to-gas)

E-fuels synthesize hydrocarbons using green hydrogen and captured CO₂ (or use green H₂ alone for e-methane). They are chemically similar to conventional fuels, making them drop-in for existing engines and infrastructure, notably in aviation and shipping. The trade-off is cost and energy intensity: converting electricity to fuel and back to motion is far less efficient than direct electrification.

Where they fit

Given their cost and limited early supply, e-fuels are best reserved for hard-to-electrify segments.

• Aviation (e-kerosene) where energy density and global compatibility are critical.
• Shipping, particularly as e-methanol or e-diesel for existing engines.
• Legacy vehicle fleets where drop-in compatibility avoids equipment turnover.
• Remote regions lacking grid capacity but with strong renewable resources for local production.

Policy support and abundant cheap renewables are prerequisites for scaling e-fuels sustainably.

Emerging options: methanol, ammonia, and dimethyl ether

Several carbon-light or carbon-free molecules are gaining traction, especially in maritime and heavy-duty applications, where liquid handling and engine compatibility matter.

Methanol

Methanol is a liquid at ambient conditions, easier to store than LNG or compressed hydrogen. Engines and fuel systems tailored for methanol are entering service in shipping. Fossil methanol offers limited climate benefits, but biomethanol and e-methanol can sharply cut lifecycle emissions. Lower energy density means larger tanks or more frequent bunkering.

Ammonia

Ammonia contains no carbon; it can be combusted in modified engines or used in fuel cells after cracking to hydrogen. It poses toxicity and NOx control challenges and has lower volumetric energy density than diesel, though higher than liquid hydrogen. “Green ammonia” made from renewable hydrogen and nitrogen is a leading candidate for long-distance shipping.

Dimethyl ether (DME)

DME burns soot-free in compression-ignition engines with modest modifications and can be produced from methanol, biomass, or biogas. It stores like LPG and can be blended into propane. Renewable DME is being piloted for trucking and off-road equipment.

Choosing the right fuel: key decision factors

Selecting an alternative fuel is a systems decision. The following factors typically drive choices for fleets, shippers, and policymakers.

• Duty cycle and range: daily miles, payload, grade, climate, and idle time.
• Infrastructure: depot vs. public fueling, grid capacity, and space constraints.
• Total cost of ownership: vehicle price, fuel/energy cost, maintenance, incentives.
• Lifecycle emissions: well-to-wheels carbon intensity and local air quality.
• Policy and compliance: zero-emission mandates, LCFS credits, tax incentives.
• Safety and training: handling, storage, and emergency response needs.
• Supply chain and scalability: feedstock limits and technology maturity.

Aligning these criteria with operational reality ensures climate gains without compromising reliability or budgets.

Quick comparison snapshot

Here’s how the major options generally stack up across common goals and constraints.

• BEVs: highest efficiency and lowest operating cost in many light/medium-duty uses; infrastructure is the main hurdle for heavy-duty corridors.
• Hydrogen: strong for high-utilization heavy-duty and rail where fast refueling matters; efficiency and station costs are challenges.
• Biofuels: immediate, drop-in emissions cuts for existing engines; sustainability and feedstock constraints cap scale.
• CNG/LNG and propane: mature, clean-burning alternatives; best when paired with RNG/renewable propane and tight methane controls.
• E-fuels: drop-in for aviation/shipping and legacy fleets; currently costly and energy-intensive, suited to scarce-renewables-rich regions.
• Methanol/ammonia/DME: emerging maritime and heavy-duty choices with growing engine support; safety, NOx control, and tankage are key.

No single fuel wins everywhere; the optimal pathway depends on sector, geography, and timelines.

Outlook through 2030

By the end of the decade, BEVs are poised to dominate new light-duty sales in many markets, supported by expanding charging and ongoing battery cost declines. In heavy-duty road transport, expect a split: battery-electric leading in regional and return-to-base operations, with hydrogen fuel-cell pilots scaling on dedicated corridors. Aviation decarbonization hinges on SAF supply growth and mandates (e.g., EU ReFuelEU Aviation), while shipping orders for methanol-capable vessels are rising and ammonia pilots are advancing. RNG will remain a niche with high climate value where waste methane can be captured. Synthetic e-fuels should expand from demonstrations to early commercial volumes in aviation and shipping, constrained by cost and renewable power availability. Policy frameworks—from the U.S. Inflation Reduction Act to EU FuelEU Maritime—will continue to shape economics and speed of adoption.

Summary

Alternative fuels now span a broad toolkit: electricity for efficiency and urban air quality; hydrogen for high-uptime heavy-duty routes; biofuels and SAF for immediate drops in existing fleets and aircraft; natural gas and propane as transitional options, especially with renewable supply; and synthetic e-fuels plus methanol, ammonia, and DME for hard-to-electrify sectors. The best choice is context-specific, balancing lifecycle emissions, infrastructure, cost, and safety. With supportive policy and targeted deployment, these fuels can collectively cut transport emissions this decade while paving the way to deeper decarbonization beyond 2030.

What are the 7 alternative sources of energy?

The 7 common alternative energy sources are Solar, Wind, Hydroelectric, Geothermal, Bioenergy, Ocean Energy (including tidal and wave), and Hydrogen Energy. These are non-fossil fuel sources, with most being renewable and replenished naturally, helping to reduce greenhouse gas emissions and combat climate change.
 
Here’s a brief description of each:

1. Solar Energy: Harnesses the sun’s light using photovoltaic cells to generate electricity. 
2. Wind Energy: Converts the kinetic energy of wind into electricity using large turbines. 
3. Hydroelectric Energy: Generates electricity by using the power of moving water in dams or rivers to spin turbines. 
4. Geothermal Energy: Utilizes heat from within the Earth to generate energy. 
5. Bioenergy: Produces heat or electricity from organic materials like wood, crops, and waste products. 
6. Ocean Energy: Captures the mechanical energy from tides and the thermal energy from differences in ocean water temperature. 
7. Hydrogen Energy: Aims to use hydrogen as a fuel, which, when used in a fuel cell, produces only water and heat as byproducts. 

What are examples of alternative fuels?

Examples of alternative fuels include ethanol (from corn or sugarcane), biodiesel (from vegetable oils or animal fats), electricity (from renewable sources), natural gas (including compressed and renewable forms), hydrogen (for fuel cell vehicles), propane (LPG), and renewable diesel (from biomass). These fuels are considered alternatives to petroleum-based fuels and are used in a variety of vehicles to help reduce greenhouse gas emissions.
 
Biofuels

• Ethanol: Opens in new tabA type of alcohol fuel made from crops like corn or sugarcane, used in flex-fuel vehicles and blended with gasoline (e.g., E85). 
• Biodiesel: Opens in new tabA fuel derived from vegetable oils or animal fats, which can be used in diesel engines, either alone or blended with petroleum diesel. 
• Renewable Diesel: Opens in new tabA biomass-derived fuel that is suitable for use in diesel engines and offers reduced lifecycle carbon emissions. 

Gaseous Fuels

• Natural Gas (CNG/RNG): Opens in new tabCompressed natural gas (CNG) and renewable natural gas (RNG) are methane-based fuels used in specially designed vehicles to reduce emissions. 
• Propane (LPG): Opens in new tabA readily available gaseous fuel that has been used for decades in various vehicles, offering advantages like lower non-carbon emissions. 
• Hydrogen: Opens in new tabAn emissions-free alternative fuel for fuel cell vehicles, which can be produced from renewable resources to further reduce carbon footprints. 

Other Alternatives

• Electricity: Opens in new tabUsed in electric vehicles (EVs), this fuel source can provide significant reductions in greenhouse gases when generated from renewable sources. 
• Methanol: Opens in new tabAn alcohol fuel that can be produced less expensively for internal combustion engines, though less common than ethanol. 
• E-fuels: Opens in new tabAlso known as synthetic fuels, these are produced using low-carbon, renewable electricity, offering the lowest GHG emissions among many alternatives but are very costly to produce, according to DieselNet. 

What are three alternative fuel sources you would choose?

Some popular alternative energy sources are wind power, hydroelectricity (water power), solar power, biofuels, and hydrogen. These fuels all have two things in common: their small environmental impact on the earth and their sustainability (never ending supply) as an energy source.

What is the best alternative fuel to use?

Contents

• Biodiesel.
• Ethanol.
• Liquefied Natural Gas.
• Liquefied Petroleum Gas.
• Compressed Natural Gas.
• Compressed Air.
• Liquid Nitrogen.
• Coal.