Sustainable aviation fuels, battery technology and design innovation show path toward lower aviation industry emissions

SAF use for long-haul flights can eliminate 50% of sector emissions but will not be cost-effective for medium-haul, regional, or short-haul, which will benefit from hybrid and electric models

Widespread use of sustainable aviation fuel (SAF) could eliminate nearly two-thirds of aviation industry emissions by 2050, according to Cleantech Group. 

Currently, such uptake is cost-effective for long-haul flights, but not for flights of shorter duration. Use of SAF in long-haul flights — which account for only 6.2% of all flights — alone can eliminate half of all aviation industry emissions. Hybrid-electric or hydrogen fuel has the potential to address emissions caused by regional, medium- and short-haul flights making up the other half of industry emissions.

“Global SAF production is increasing rapidly, but uptake remains at 0.2% of all global aircraft fuel. Airlines and operators are actively engaging with decarbonization solutions such as electric, hydrogen, and hybrid aircrafts to achieve high rates of decarbonization without relying on the uncertain SAF market,” said Nicole Cerulli, Associate, Transportation & Logistics.

“These technologies reduce fuel and operations costs and will be compatible with SAF when supply scales sufficiently to meet demand,” she added.

Other key findings: 

Europe is early leader. Europe and European carriers dominate use of SAF with an 80% market share. North America comes second with 16%, while the rest of the world uses about 4%. Air France-KLM, logistics giant DHL and IAG, the parent company of British Airways, have led Europe, as usage across the continent grew to 167,000 tons in 2023. Europe has now set a higher goal — targeting another 1 million tons of SAF by 2025. 

Corporates driving uptake. Key drivers are decarbonization goals for 2050 set for their members by the International Air Transport Association (IATA) and International Civil Aviation Organization (ICAO) as well as minimum SAF uptake mandates in the EU. While SAF premiums are currently exorbitant, many major airlines and operators have established uptake targets. Key demand owners for SAF are financial corporations aiming to reduce Scope 3 emissions (emissions emerging outside of an organization’s direct control but still seen as a result of the organization's business activities). 

Hybrid offers fastest path. Hybrid-electric aircraft with capabilities to cut emissions from 40% to 100% offer the quickest way to market. Such solutions can be enabled via retrofitting or new build aircrafts and can be scaled to regional narrowbody flights carrying about 150 passengers over the next decade. Additionally, by cutting operational cost by about 40%, hybrid aircraft improve route economics and offset green premiums. 

SAF supply remains a bottleneck. Supply of SAF remains constrained, posing a challenge to greater adoption. The U.S. is a leader with 79,000 tons in 2023. It remains on track to produce more SAF in 2024 than the world’s production in 2023. Yet, it needs a challenging 97% compound annual growth rate (CAGR) for the next several years to meet 2030 targets. 

Battery technology is key barrier. Energy density of batteries poses the single most important challenge toward electrification of larger aircraft and in expanding the flying range for all aircraft. For effective electrification of regional and short-haul aircraft alone, battery density needs to triple. Limited advances in hydrogen fuel cell technology similarly limit the adoption of an alternative technology to power aircraft, but a breakthrough could be sighted from innovations in storage of liquid hydrogen. 

Design solutions emerging. Innovative aircraft design that reduces weight and drag, lowering engine or motor requirements and improving fuel efficiency, is expected to provide a new thrust to the quest to cut aviation industry emissions. Early results have shown promise. Jetzero’s blended-wing-body aircraft halves emissions, while Natilus’ similar aircraft for cargo transport can cut emissions by 50%. Hybrid Air Vehicles, which has developed an airship leveraging helium to increase hull buoyancy, says its innovation can cut 75% of emissions. The technology enjoys a key advantage because it is compatible with aircraft running on an internal combustion engine and electric propulsion.