Seattle-Tacoma International Airport has unveiled a plan to transition all departing flights from conventional jet fuel to aviation biofuel. The proposal follows a feasibility study presented at a Jan. 12 event and represents the first regional assessment of this kind in the United States.
Worldwide, roughly 2,500 test flights have already used biofuels — including fuels derived from algae, used cooking oil and industrial oilseed crops — demonstrating that commercial aircraft can travel long distances without relying solely on petroleum-based jet fuel.
Despite those demonstrations, regular commercial use of aviation biofuel remains limited in the U.S. Currently, Los Angeles International Airport is the only U.S. airport that incorporates biofuel into regular operations: United Airlines has a three-year contract with AltAir Fuels to blend a small percentage of biofuel into flights departing LAX.
Outside of that arrangement, a broad commercial supply of aviation biofuel is not yet available in the United States. “We can’t just go buy fuel,” said Carol Sim, environmental affairs director for Alaska Airlines, underscoring that supply chains and production capacity are still developing.
The Sea-Tac feasibility study was intended in part to signal market demand to potential producers and suppliers. By quantifying local demand, the airport hopes to encourage investment in regional biofuel production and distribution infrastructure.
Next steps for Sea-Tac include working through the economics and logistics required to implement the transition. That includes identifying reliable feedstocks, securing long-term supply contracts, evaluating blending and storage requirements at fuel farms, and coordinating with airlines, fuel suppliers and regulators to ensure safe, efficient operations.
Operational challenges extend beyond production. Aviation biofuels must meet strict certification standards and integrate with existing fueling systems without disrupting airline schedules or increasing safety risk. Cost is another major factor: biofuels have generally remained more expensive than conventional jet fuel, so any airport-wide shift would likely require public-private partnerships, incentives, or long-term contracts to make prices competitive for airlines.
Advocates argue that scaling up aviation biofuel use could significantly reduce greenhouse gas emissions from air travel, especially when feedstocks are produced sustainably and lifecycle emissions are carefully managed. By creating a larger, predictable market for sustainable aviation fuels, Sea-Tac’s study aims to help spur regional production and supply chain development.
For now, the study serves as a blueprint rather than a finalized policy. Sea-Tac still needs to refine cost estimates, confirm supply options, and coordinate with stakeholders to develop a practical implementation timeline. If successful, the plan could position the airport as a leader in reducing aviation emissions and provide a model for other regions considering similar transitions.