Why We Don’t Use Biofuels Everywhere

We don’t rely on biofuels more widely because truly sustainable supply is limited, climate benefits vary by feedstock and farming practices, costs remain high in many cases, engines and fuel infrastructure impose blend limits, and electrification often delivers more energy and emissions savings per hectare and per dollar. Biofuels are used today—sometimes at scale—but they fill specific niches rather than replacing fossil fuels across the board.

What We Mean by “Biofuel,” and How Much We Use Now

Biofuels are liquid or gaseous fuels made from biological material such as crops, agricultural residues, forestry waste, used cooking oil, or animal fats. The most common are ethanol (blended with gasoline), biodiesel (FAME), renewable diesel (HVO, a drop-in diesel), biogas/renewable natural gas, and sustainable aviation fuel (SAF). They already account for a single-digit share of transport energy globally—roughly in the low-to-mid single digits—mostly in road transport. The United States blends ethanol (typically E10) into almost all gasoline; Brazil runs extensive sugarcane ethanol use with flex-fuel cars; Europe has relied heavily on biodiesel and is rapidly adopting renewable diesel. SAF use is rising from a tiny base as mandates start to bite—Europe’s ReFuelEU Aviation requires a minimum share of SAF beginning in 2025, and the United States has new tax credits under the Inflation Reduction Act to stimulate production. Still, overall penetration remains modest relative to total transport energy demand.

The Main Constraints

Several systemic factors limit how far and fast biofuels can scale without unintended consequences. These include environmental, resource, and economic realities that don’t disappear with better refineries alone.

• Land use and food competition: Turning cropland to fuel can displace food production and drive indirect land-use change (ILUC), which can erase climate gains. Expanding biofuel crops may push agriculture into carbon-rich ecosystems.
• Limited sustainable feedstocks: Waste oils, fats, and residues are finite—globally only on the order of tens of millions of tonnes per year—far short of the hundreds of millions needed to replace petroleum at scale.
• Variable climate benefits: Lifecycle emissions range widely. Sugarcane ethanol and waste-based fuels often cut emissions substantially, while some crop-based fuels can deliver small benefits—or even net harm—once fertilizer use, nitrous oxide, and ILUC are included.
• Water, fertilizer, and pollution: Many biofuel crops demand significant irrigation and inputs, contributing to water stress, nutrient runoff, and air pollution from ammonia and particulate matter.
• Biodiversity impacts: Large monocultures reduce habitat diversity; residue removal can deplete soil carbon and harm soil health if not carefully managed.
• Energy return and density: Some biofuels offer modest energy returns compared with the fuel and inputs invested, and ethanol’s lower energy density reduces vehicle range without engine optimization.
• Cost and price volatility: Renewable diesel and SAF often cost 2–4 times more than fossil counterparts without credits; feedstock prices swing with global food and oil markets.
• Competition from electrification: Battery-electric vehicles convert energy to motion far more efficiently than internal combustion engines, making electricity a more land- and energy-efficient decarbonization path for many road uses.
• Accounting uncertainty: Disputes over how to count ILUC, soil carbon, and non-CO2 gases (notably nitrous oxide) create policy and investor uncertainty.

Together, these constraints mean that while some biofuels deliver real climate benefits, scaling indiscriminately can shift problems rather than solve them, and the most sustainable feedstocks can’t cover total demand.

Technical and Market Limitations

Even when feedstock is available, engines, standards, and infrastructure limit how much biofuel the market can absorb today—especially for road transport.

• The “blend wall”: Most U.S. gasoline is E10; moving to E15 faces vehicle warranty limits, fueling infrastructure upgrades, and seasonal volatility rules (though temporary waivers have allowed some summer E15 sales).
• Engine compatibility: Many carmakers approve only low biodiesel blends (B5–B20). Higher blends can create problems without modifications; E85 requires flex-fuel vehicles.
• Cold-flow and emissions issues: Biodiesel can gel in cold weather and historically increased NOx emissions in some engines; renewable diesel mitigates many of these issues but is costlier.
• Infrastructure and logistics: Ethanol is shipped separately and splash-blended because it absorbs water; dedicated tanks, seals, and dispenser upgrades add cost and complexity.
• Refinery and pipeline constraints: Co-processing bio-oils in refineries and transporting high-oxygen fuels in pipelines remain limited by materials, standards, and corrosion risk.
• Seasonality and supply chains: Agricultural harvest cycles, quality variability, and competing uses (food, feed, oleochemicals) complicate steady fuel supply.
• Sector-specific performance: Aviation and shipping require “drop-in” fuels meeting strict standards (e.g., ASTM for SAF), narrowing eligible pathways and feedstocks.

These practical barriers don’t preclude growth, but they slow adoption and keep many markets anchored to low-blend levels or more expensive drop-in options.

Policy and Economics Shape the Ceiling

Government mandates and credits are pivotal for biofuels, but design choices and uncertainty also curb investment and deployment. Markets move where incentives are predictable and sustainability rules are clear.

• Policy uncertainty: Shifting targets under the U.S. Renewable Fuel Standard, changing state clean-fuel credit prices, and evolving EU sustainability criteria complicate long-term planning.
• Sustainability caps: The EU’s Renewable Energy Directive limits crop-based biofuels (capped around 7% of transport energy) and favors advanced fuels, constraining growth from conventional feedstocks.
• Competing incentives: Electrification policies (EV mandates, charging investments) steer capital toward batteries for light-duty transport, where they are most efficient.
• High capital costs: Biorefineries are costly, with feedstock risk, permitting hurdles, and community concerns about air and water impacts.
• Feedstock competition and fraud risks: Rapid demand for used cooking oil and tallow has outpaced audited supply, triggering investigations and tighter verification in Europe; trade barriers and sustainability audits affect flows.

Where policies are stable and targeted—such as California’s Low Carbon Fuel Standard, Europe’s ReFuelEU Aviation mandate from 2025, and U.S. tax credits for SAF and low-carbon fuels—investment rises, but still within the bounds of sustainable feedstock and technology readiness.

Where Biofuels Are Likely to Matter Most

Biofuels have a strategic role where batteries or direct electrification are hardest: long-haul aviation, parts of maritime shipping, and segments of heavy-duty road transport. Drop-in renewable diesel has already overtaken biodiesel in places like California due to better performance, and SAF is set to grow as mandates tighten through the 2030s. Advanced pathways—cellulosic ethanol, gasification-to-liquids, alcohol-to-jet, and co-processing of bio-oils—can deliver deeper emissions cuts when based on wastes and residues, though commercial scale remains limited. Even with robust growth, limited sustainable feedstock means biofuels will complement, not replace, electrification.

What Would Need to Change for Wider Use

To expand biofuels without compromising climate, food security, or biodiversity, several developments would be necessary across technology, policy, and land management.

1. Scale sustainable feedstocks: Tap agricultural and forestry residues, cover crops, municipal solid waste, and manure while protecting soil carbon and ecosystems.
2. Commercialize advanced conversion: Bring cellulosic, gasification/FT, pyrolysis, and alcohol-to-jet pathways to reliable, bankable scale.
3. Sharpen carbon accounting: Harmonize lifecycle methods for ILUC, soil carbon, and non-CO2 gases to guide investment toward genuinely low-carbon options.
4. Invest in infrastructure: Upgrade blending, storage, and dispensing systems and enable engines certified for higher blends where appropriate.
5. Stabilize policy: Long-term, technology-neutral carbon pricing or durable clean-fuel standards can support investment without boom–bust cycles.
6. Protect food and nature: Set firm sustainability guardrails and traceability to prevent deforestation, habitat loss, and food-price shocks.
7. Boost agricultural efficiency: Precision fertilizer use, better crop rotations, and soil management to cut nitrous oxide and enhance yields.
8. Pursue breakthroughs: Develop high-yield feedstocks (including algae) and biotechnologies that lift energy returns and reduce inputs.

These steps won’t make biofuels a silver bullet, but they would expand the sustainable slice of the energy mix where liquid fuels are hardest to substitute.

Bottom Line

We don’t use biofuels everywhere because the sustainably available resource is limited, climate benefits depend heavily on how and where fuels are made, costs are still high for the best options, and engines and infrastructure constrain uptake—while electrification is simply more efficient for many uses. Expect biofuels to play a growing but targeted role—especially in aviation, shipping, and some heavy-duty applications—within a broader transition led by efficiency and electrification.

Summary

Biofuels are part of today’s energy mix, but their expansion is constrained by land and feedstock limits, uneven climate performance, higher costs, and technical and policy barriers. The most credible growth lies in drop-in fuels made from wastes and residues for sectors that are hard to electrify, supported by stable, sustainability-focused policy and continued technological improvement.

What is the main problem with biofuels?

Biofuel production and use has drawbacks as well, including land and water resource requirements, air and ground water pollution. Depending on the feedstock and production process, biofuels can emit even more GHGs than some fossil fuels on an energy -equivalent basis.

What are 5 disadvantages of biofuel?

What are 6 disadvantages of biofuel?

• Biofuels, derived from organic matter like plant materials and animal waste, offer a promising avenue for renewable energy.
• Land Use Issues.
• High Cost.
• Food Security.
• Energy Intensive Production.
• Limited Availability.
• Greenhouse Gas Emissions.

Why don’t we have functional biofuel yet?

And growing corn for ethanol can directly compete with food production. After growing it we have to then process that raw corn into fuel. This is time money and energy expensive.

Why don’t we use biofuels?

Disadvantages of Biofuels: Biofuels Threaten Public Health
In addition to spewing climate-warming emissions, biofuels also pollute our air. Burning these fuels produces tiny toxic particles, ozone, and nitrogen dioxide.