Interview: Practitioners on Sustainable aviation & shipping — what they wish they knew earlier

Sustainable aviation fuel (SAF) accounted for less than 0.2% of total global jet fuel consumption in 2025, yet the European Union's ReFuelEU Aviation regulation now mandates a 6% SAF blending requirement by 2030 and 70% by 2050. In maritime shipping, the International Maritime Organization's revised greenhouse gas strategy targets net-zero emissions by or around 2050, while fewer than 3% of the global fleet currently operates on alternative fuels. For procurement professionals navigating this transition, the gap between regulatory ambition and operational reality creates a landscape of steep learning curves, expensive missteps, and hard-won insights that rarely appear in industry whitepapers. Six practitioners across aviation and maritime shipping shared what they wish they had known before committing capital and organizational resources to decarbonization programs.

Why It Matters

Aviation and shipping together account for approximately 5% of global CO2 emissions, a share projected to grow to 10% by 2050 under business-as-usual scenarios as other sectors decarbonize faster (International Energy Agency, 2025). The EU Emissions Trading System now covers maritime shipping as of January 2024, and the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) entered its mandatory phase in 2027. European procurement teams face direct cost exposure through carbon pricing mechanisms, fuel mandates, and customer-driven Scope 3 reduction requirements.

The financial stakes are substantial. Airlines that secured long-term SAF offtake agreements before 2024 locked in prices of $3.50 to $5.00 per gallon, while spot market SAF prices in early 2026 reached $7.00 to $9.50 per gallon in European markets. In shipping, the cost premium for green methanol over conventional heavy fuel oil ranges from 200% to 400%, depending on feedstock source and regional availability (DNV, 2025). Procurement decisions made today on fuel contracts, vessel specifications, and supply chain partnerships will determine cost competitiveness for the next decade.

Key Concepts

Understanding the sustainable transport fuels landscape requires familiarity with several foundational elements.

Sustainable Aviation Fuel (SAF): Drop-in jet fuel produced from non-petroleum feedstocks including used cooking oil, agricultural residues, municipal solid waste, and synthetic pathways using green hydrogen and captured CO2. SAF achieves lifecycle emission reductions of 50% to 80% compared to conventional jet fuel, depending on the production pathway and feedstock.

HEFA Pathway: Hydroprocessed Esters and Fatty Acids, currently the dominant SAF production pathway representing over 85% of global SAF output. HEFA relies on lipid feedstocks (used cooking oil, animal fats, vegetable oils) and faces long-term feedstock constraints as demand scales.

Power-to-Liquid (PtL) or e-SAF: Synthetic SAF produced by combining green hydrogen with captured CO2 via Fischer-Tropsch synthesis. PtL offers virtually unlimited feedstock potential but costs 3 to 5 times more than HEFA SAF at current production scales.

Green Shipping Corridors: Bilateral or multilateral agreements between ports to establish zero-emission maritime routes, with dedicated fueling infrastructure, regulatory alignment, and vessel deployment. Over 30 green shipping corridor initiatives were announced between 2021 and 2025, though fewer than 5 have achieved operational status with vessels running on alternative fuels (Global Maritime Forum, 2025).

FuelEU Maritime: EU regulation effective January 2025 that sets progressively tightening greenhouse gas intensity limits for energy used by ships calling at European ports, reaching a 80% reduction by 2050 relative to 2020 baselines.

What's Working

Practitioners identified several approaches delivering measurable results across aviation and maritime decarbonization.

Long-term SAF offtake agreements with dedicated production capacity are proving essential for cost management and supply security. Lufthansa Group signed a 9-year agreement with HCS Group in 2024 for 1.8 million tonnes of SAF produced at a facility in Speyer, Germany, securing supply at 40 to 50% below projected spot prices by locking in volume commitments before regulatory mandates created demand surges. The agreement includes feedstock diversification clauses that allow transitioning from HEFA to alcohol-to-jet pathways as production technology matures.

In maritime shipping, dual-fuel vessel orders are accelerating practical learning. Maersk took delivery of its first methanol-capable container vessels in 2024, with 25 vessels in its fleet now capable of running on green methanol. The company's procurement team found that specifying dual-fuel capability at the newbuild stage adds approximately 8 to 12% to vessel capital costs, while retrofit costs for existing vessels range from 25 to 40% of hull value, making newbuild specification the clear economic choice (Maersk, 2025).

Book-and-claim accounting systems for SAF are enabling airlines and corporate buyers to decouple the physical delivery of SAF from the environmental attribute, dramatically expanding procurement options. KLM Royal Dutch Airlines pioneered this approach in Europe through its Corporate SAF Programme, which allows corporate customers to purchase SAF certificates tied to verified production and blending at any qualifying airport. This mechanism solved the logistical challenge that SAF cannot be physically delivered to every airport, allowing corporate buyers in secondary markets to claim emissions reductions without requiring dedicated SAF infrastructure at their departure points.

Collaborative procurement consortia are reducing per-unit costs and sharing risk. The Cargo Owners for Zero Emission Vessels (coZEV) coalition, which includes Amazon, IKEA, Patagonia, Unilever, and Michelin, pools demand commitments to underwrite zero-emission shipping capacity on specific trade lanes. By aggregating cargo volume from multiple shippers, coZEV has enabled vessel operators to justify the capital investment in alternative fuel vessels on the Asia-to-Europe corridor.

What's Not Working

Practitioners were equally candid about persistent challenges and outright failures.

Voluntary SAF purchases without regulatory mandates have failed to achieve meaningful scale. Despite corporate sustainability pledges from over 80 major airlines and 200 corporate travel programs, voluntary SAF procurement remained below 500,000 tonnes globally in 2025 against a production capacity of roughly 1.5 million tonnes. Practitioners attribute this to the "green premium problem": voluntary purchases carry a 200 to 400% cost premium over conventional jet fuel, and without mandate-driven demand, airlines and corporates default to purchasing carbon offsets at a fraction of the cost.

Feedstock competition is already constraining HEFA SAF production. Used cooking oil (UCO), the primary HEFA feedstock, faces competing demand from renewable diesel production for road transport, biodiesel mandates, and the oleochemical industry. European UCO prices increased 65% between 2023 and 2025, and documented cases of virgin palm oil being fraudulently relabeled as UCO have undermined feedstock integrity. The International Council on Clean Transportation estimates that sustainable lipid feedstock availability can support a maximum of 5 to 7 million tonnes of HEFA SAF per year globally, far below the 30 to 40 million tonnes needed to meet 2035 blending mandates (ICCT, 2025).

Green shipping corridors remain largely aspirational. Of the 30-plus announced corridors, most lack binding fuel supply agreements, port infrastructure commitments, or regulatory incentives beyond letters of intent. The Los Angeles-to-Shanghai green corridor initiative, launched with significant fanfare in 2022, has not deployed a single zero-emission vessel as of early 2026 due to unresolved questions around methanol bunkering infrastructure at Shanghai port and disagreements over cost-sharing between vessel operators and cargo owners.

Ammonia as a marine fuel faces safety and regulatory barriers that practitioners underestimated. While ammonia offers high energy density and zero-carbon combustion, its acute toxicity (lethal concentration in air at 300 ppm for 30-minute exposure) creates port safety, crew training, and bunkering infrastructure challenges that have delayed commercial deployment by 3 to 5 years versus initial industry projections. Classification society DNV reported that only 4 ammonia-fueled vessels were in operation globally by end of 2025, versus 68 methanol-fueled vessels (DNV, 2025).

Key Players

Established Companies

• Neste: World's largest SAF producer with 1.5 million tonnes per year capacity across facilities in Singapore, Rotterdam, and Porvoo, Finland
• Maersk: Leading container shipping line with 25 methanol-capable vessels in fleet and target to reach net-zero by 2040
• Airbus: Aircraft manufacturer developing hydrogen-powered aircraft concepts and certifying 50% SAF blend capability across current fleet
• TotalEnergies: Integrated energy company investing $1.5 billion in SAF production capacity targeting 1.5 million tonnes per year by 2030
• CMA CGM: French shipping group with orders for 44 LNG-powered vessels and investments in methanol and wind-assisted propulsion

Startups and Innovators

• Twelve (formerly Opus 12): Produces e-SAF through CO2 electrolysis and Fischer-Tropsch synthesis, with a demonstration facility in Washington state
• Infinium: Power-to-liquid SAF producer with commercial plant in Corpus Christi, Texas producing ultra-low carbon electrofuels
• Bound4Blue: Spanish company deploying rigid wingsails for wind-assisted ship propulsion, achieving 10 to 30% fuel savings on cargo vessels
• Anemoi Marine Technologies: Develops Flettner rotor systems for wind-assisted propulsion retrofittable to existing commercial vessels

Investors and Funders

• Breakthrough Energy Ventures: Bill Gates-backed climate fund with investments in SAF producers including LanzaJet and Infinium
• AP Moller Holding: Family holding company behind Maersk, investing in green methanol production and maritime decarbonization infrastructure
• BlackRock: Institutional investor with dedicated climate infrastructure funds targeting maritime and aviation decarbonization projects

Action Checklist

• Audit current aviation and shipping spend to quantify carbon exposure under EU ETS maritime coverage and CORSIA mandatory phase pricing
• Engage with 2 to 3 SAF producers to explore long-term offtake agreements before 2030 mandate deadlines compress available supply
• Evaluate book-and-claim SAF procurement for corporate travel programs where physical SAF delivery is not feasible at departure airports
• Specify dual-fuel capability in all newbuild vessel orders and charter party agreements to avoid costly retrofit requirements
• Join a collaborative procurement consortium such as coZEV to aggregate demand and share risk on zero-emission shipping lanes
• Develop feedstock diversification requirements in SAF contracts to avoid overexposure to UCO price volatility and supply constraints
• Assess FuelEU Maritime compliance pathway for vessels calling at European ports, including pooling and banking provisions
• Build internal competency on fuel lifecycle analysis to verify supplier emission reduction claims and avoid greenwashing risks

FAQ

Q: How should procurement teams evaluate SAF suppliers given feedstock fraud concerns? A: Require suppliers to hold ISCC EU or RSB certification with full chain-of-custody documentation from feedstock collection to final blending. Request third-party mass balance verification and include contractual provisions for independent feedstock audits. The EU's delegated act under ReFuelEU Aviation specifies eligible feedstock pathways and sustainability criteria, providing a regulatory baseline for supplier qualification. Avoid suppliers who cannot demonstrate feedstock traceability to the point of collection or who offer pricing significantly below market rates for their stated feedstock type.

Q: What is the realistic cost trajectory for SAF over the next decade? A: HEFA SAF is expected to decline from current levels of $5.00 to $7.00 per gallon to $3.50 to $4.50 per gallon by 2030 as production capacity scales, though feedstock constraints cap long-term cost reduction potential. Power-to-liquid SAF, currently at $12 to $20 per gallon, is projected to reach $4.00 to $6.00 per gallon by 2035 as electrolyzer costs fall and green hydrogen production scales. The convergence point where PtL SAF reaches cost parity with HEFA is expected between 2032 and 2036, depending on green hydrogen cost trajectories and carbon pricing levels (IEA, 2025).

Q: Should procurement teams prioritize methanol or ammonia for maritime fuel transition? A: Methanol has a clear near-term advantage due to simpler handling requirements, existing port infrastructure adaptability, and a growing fleet of operational dual-fuel vessels. Ammonia offers superior energy density and zero-carbon combustion but faces 3 to 5 year delays in safety certification, bunkering standards, and crew training protocols. For procurement decisions on vessels ordered today with delivery in 2027 to 2029, methanol-capable dual-fuel specification is the lower-risk choice. Monitor ammonia developments for fleet decisions beyond 2030.

Q: How do European regulations compare to requirements in other jurisdictions? A: Europe leads with the most comprehensive regulatory framework combining ReFuelEU Aviation SAF mandates, FuelEU Maritime intensity targets, and EU ETS coverage for both sectors. The US Inflation Reduction Act provides tax credits of $1.25 to $1.75 per gallon for SAF meeting minimum lifecycle reduction thresholds but does not mandate blending. Singapore has implemented a maritime decarbonization levy starting in 2027. China has not yet implemented SAF mandates but has signaled policy development for its 15th Five-Year Plan period (2026 to 2030). Procurement teams operating globally should design compliance strategies around the most stringent jurisdiction, which currently is the EU.

Sources

• International Energy Agency. (2025). Net Zero Roadmap: Aviation and Shipping Sectors Update. Paris: IEA.
• DNV. (2025). Maritime Forecast to 2050: Energy Transition Outlook. Hovik, Norway: DNV AS.
• International Council on Clean Transportation. (2025). Sustainable Aviation Fuel Feedstock Availability and Demand Projections. Washington, DC: ICCT.
• Global Maritime Forum. (2025). Annual Progress Report on Green Shipping Corridors. Copenhagen: Global Maritime Forum.
• Maersk. (2025). Sustainability Report 2024: Fleet Decarbonization Progress and Methanol Transition Update. Copenhagen: A.P. Moller-Maersk.
• European Commission. (2024). ReFuelEU Aviation: Delegated Acts on SAF Sustainability Criteria and Monitoring. Brussels: European Commission.
• Lufthansa Group. (2024). Sustainable Aviation Fuel Strategy: Long-Term Offtake Agreements and Supply Chain Development. Frankfurt: Deutsche Lufthansa AG.