Sustainable Aviation
Delta Air Lines 2025 Sustainability Progress: Fuel Savings and Fleet Upgrades
Delta Air Lines reports saving 55 million gallons of fuel in 2025 while advancing fleet modernization and increasing Sustainable Aviation Fuel use by 50%.

This article is based on an official press release from Delta Air Lines and includes additional industry context.
Delta Air Lines Reports 2025 Sustainability Milestones: Fleet Upgrades and Operational Efficiency
Delta Airlines has released its 2025 sustainability progress report, detailing significant advancements in its “Keep Climbing” strategy. According to the airline, the focus for the year remained on immediate operational efficiencies and long-term technological investments aimed at decarbonization. The carrier reported meeting critical fuel-saving targets while laying the groundwork for future fleet innovations.
In an official statement, Delta highlighted progress across three strategic pillars: fleet modernization, operational changes, and the scaling of Sustainable Aviation Fuel (SAF). The airline confirmed it achieved a near-term goal of 1% fuel burn savings, equating to approximately 55 million gallons of fuel saved throughout the year. These efforts are part of a broader push to mitigate the environmental impact of aviation while managing the economic realities of fuel costs.
Pillar 1: Fleet Modernization and Future Tech
A central component of Delta’s strategy involves replacing older, less efficient jets with next-generation Commercial-Aircraft. The airline reported taking Delivery of over 35 new aircraft in 2025, a move that improved the average fuel efficiency of its fleet by approximately 25% compared to the retired models they replaced.
Next-Generation Orders
Looking ahead, Delta has secured orders for 20 Airbus A350-1000 aircraft, with deliveries expected to commence in 2026. According to manufacturer specifications cited in the release, these widebody jets are 20-25% more fuel-efficient per seat mile than the Boeing 767 and 777 aircraft they are intended to replace.
Investments in Radical Design
Beyond traditional tube-and-wing aircraft, Delta is investing in revolutionary airframe concepts. The airline is a key partner for JetZero, a company developing a “blended wing body” aircraft. Independent analysis suggests this design could reduce fuel burn by up to 50% by generating lift across the entire airframe, though entry into service is projected for 2030 or later.
Additionally, Delta has partnered with Dutch startup Maeve Aerospace to develop the M80 hybrid-electric regional aircraft. This concept promises 40% higher fuel efficiency than current regional jets, with a potential timeline for entry around 2032.
Pillar 2: Operational Efficiency
While fleet renewal offers long-term gains, Delta’s “Carbon Council”, a cross-divisional team, focused on immediate tactical changes to reduce fuel consumption in 2025. These measures allowed the airline to meet its goal of saving over 55 million gallons of fuel.
Key operational initiatives included:
- APU Reduction: Decreasing the use of Auxiliary Power Units on the ground in favor of electric ground power.
- Engine Foam Wash: Implementing a new cleaning technique that removes debris more effectively than water, thereby improving thermal efficiency.
- Drag Reduction: Installing enhanced winglets and implementing reduced-flaps landings on the Boeing 717 fleet to lower drag and noise.
AirPro News Analysis: The Financial Impact
These efficiency gains have direct financial implications. Based on estimated jet fuel prices of $2.50 to $2.70 per gallon, the 55 million gallons saved in 2025 translates to roughly $130 million to $150 million in cost savings. This operational discipline likely contributed to the airline’s strong financial performance, which allowed for a $1.4 billion profit-sharing payout to employees in February 2025.
Pillar 3: Scaling Sustainable Aviation Fuel (SAF)
Delta continues to aggressively scale its use of Sustainable Aviation Fuel (SAF), despite facing industry-wide supply constraints. The airline reported it was on track to increase SAF usage by 50% in 2025 compared to 2024 levels, moving from approximately 13 million to 20 million gallons.
The PDX Milestone
A significant achievement in 2025 was the first commercial-scale SAF uplift at Portland International Airport (PDX). In partnership with Shell Aviation and Montana Renewables, this project demonstrated that SAF can be “dropped in” to existing airport infrastructure, such as pipelines and storage tanks, without the need for specialized modifications.
“This project proved that SAF can be dropped into existing airport fuel infrastructure without requiring specialized modifications, a critical step for mass adoption.”
, Industry analysis regarding the PDX milestone
Industry Context and Competitive Landscape
While Delta is making strides, it operates in a highly competitive environment regarding fuel efficiency. Data from analytics firms like Cirium indicates that ultra-low-cost carriers such as Frontier and Spirit often lead the U.S. market in fuel efficiency per seat mile, largely due to their high-density seating configurations.
Among legacy carriers, Southwest Airlines typically leads in efficiency metrics, with Delta, United, and American closely grouped. However, Delta often outperforms peers on specific international routes due to its investment in newer widebody aircraft like the A350 and A330neo.
Challenges to Scaling
Despite the progress, the “Green Premium” remains a hurdle. SAF currently costs two to five times more than conventional jet fuel, and global production accounts for less than 0.5% of total demand. Delta’s goal of 10% SAF usage by 2030 is ambitious and will require continued government support, such as the incentives provided by the Minnesota SAF Hub, to become a reality.
Frequently Asked Questions
What is the “Blended Wing Body” aircraft Delta is investing in?
The Blended Wing Body is a design by JetZero where the aircraft fuselage and wings are integrated, generating lift across the entire body. It aims to reduce fuel consumption by 50% compared to traditional aircraft.
How much fuel did Delta save in 2025?
Delta reported saving approximately 55 million gallons of fuel in 2025 through operational efficiencies, meeting its 1% savings goal.
What is the significance of the PDX SAF project?
The project at Portland International Airport demonstrated that Sustainable Aviation Fuel can be used with existing airport pipelines and storage, removing the need for expensive new infrastructure to handle the fuel.
Sources
Photo Credit: Delta Air Lines
Sustainable Aviation
Phelan Green Chooses Honeywell Tech for South African eSAF Facility
Phelan Green invests $2.5B in South Africa to build an electro-sustainable aviation fuel plant using Honeywell’s Fischer Tropsch technology.

This article is based on an official press release from Honeywell.
Phelan Green, operating through its clean fuels subsidiary Phelan eFuels, has officially selected Honeywell’s renewable fuel process technology for a major new electro-sustainable aviation fuel (eSAF) facility. The planned production site will be located in Saldanha Bay, Western Cape, South Africa, marking a significant step forward for the region’s emerging green energy economy.
According to a company press release, the facility will utilize Honeywell UOP’s Fischer Tropsch (FT) Unicracking process technology. This system is designed to convert FT liquids and waxes derived from carbon dioxide into sustainable aviation fuel that meets rigorous aviation industry standards.
The development represents a major milestone in the global push to decarbonize commercial aviation. By leveraging advanced processing technologies, the project aims to establish South Africa as a competitive export hub for next-generation aviation fuels.
Project Scope and Economic Impact
The new Saldanha Bay facility is a core component of the broader Phelan Green Hydrogen Project. The initiative represents a private investment of R47 billion, which is approximately $2.5 billion USD. The South African government has formally recognized the endeavor as a nationally strategic green industrial development, underscoring its importance to the country’s economic and environmental goals.
Once operational, the site is expected to be among the world’s first commercial-scale eSAF production facilities. The press release notes that the plant will supply more than 140,000 tons of electro-sustainable aviation fuel to markets in the European Union and the United Kingdom.
Construction Timeline and Job Creation
Construction on the Saldanha Bay facility is scheduled to begin in the fourth quarter of 2026. The multi-phase development process is projected to support thousands of local jobs, providing a substantial boost to the regional economy in the Western Cape.
Company leadership emphasized the strategic value of the partnership. Paschal Phelan, Chairman of Phelan Green, highlighted the reliability of the chosen technology in the official announcement.
“We selected Honeywell’s Fischer Tropsch Unicracking process technology because it provides a proven, bankable pathway to produce sustainable aviation fuel at scale,” Phelan stated in the press release.
Technological Framework and Industry Transition
The transition to sustainable aviation fuel is highly dependent on scalable and efficient processing technologies. Honeywell’s FT Unicracking system plays a critical role by upgrading synthetic liquids into drop-in aviation fuels that do not require modifications to existing aircraft engines or fueling infrastructure.
Rajesh Gattupalli, president of Honeywell UOP, noted that the company’s technologies are specifically engineered to facilitate the flexible production of low-carbon fuels.
“In this case, our Fischer Tropsch Unicracking process technology will help support Phelan eFuels’ goal to encourage commercial scale sustainable aviation fuel production in South Africa,” Gattupalli said in the company statement.
AirPro News analysis
We view the Phelan Green Hydrogen Project as a critical indicator of how global capital is beginning to flow toward commercial-scale eSAF production. The $2.5 billion investment highlights the growing viability of power-to-liquid technologies, which are essential for producing aviation fuels from captured carbon dioxide and green hydrogen.
Furthermore, targeting the EU and UK markets with the planned 140,000 tons of eSAF aligns with the stringent blending mandates recently introduced in those regions. As European regulations increasingly require airlines to incorporate sustainable fuels, export-oriented facilities in regions with abundant renewable energy potential, such as South Africa, are well-positioned to capitalize on the surging demand.
Frequently Asked Questions
What is eSAF?
Electro-sustainable aviation fuel (eSAF) is a type of synthetic fuel produced using renewable electricity, water, and carbon dioxide. It is designed to replace conventional jet fuel while significantly reducing greenhouse gas emissions.
Where will the new facility be located?
The planned production facility will be built in Saldanha Bay, located in the Western Cape province of South Africa.
When does construction begin?
According to the project timeline, construction of the Saldanha Bay facility is set to commence in the fourth quarter of 2026.
Sources
Photo Credit: Honeywell
Sustainable Aviation
Airbus-led ECLIF-X Campaign Studies Aviation Non-CO2 Emissions 2025-2027
The ECLIF-X campaign investigates how low-sulphur and low-aromatic fuels reduce contrail formation and non-CO2 emissions in aviation from 2025 to 2027.

This article is based on an official press release from Airbus.
In a closely coordinated chase across the sky, the aviation industry is taking aim at one of its most visible and complex climate challenges: condensation trails. While carbon dioxide emissions have long dominated sustainability discussions, recent scientific consensus highlights that non-CO2 emissions account for a significant portion of commercial aviation’s total climate warming impact.
To address this, Airbus, the German Aerospace Center (DLR), and engine manufacturer Pratt & Whitney have launched ECLIF-X (Emissions and Climate Impact of alternative Fuels – X). According to an official Airbus press release, this joint research campaign utilizes a “flying laboratory” to investigate the effects of fuel composition on aviation’s non-CO2 impact.
Running from 2025 to 2027, the ECLIF-X campaign captures real-time data on how low-sulphur and low-aromatic fuels interact with advanced engine combustors. At AirPro News, we recognize this initiative as a critical step toward understanding and mitigating the formation of climate-warming contrails before new environmental regulations take full effect.
The ECLIF-X Campaign: A High-Altitude Chase
The Emitter and the Sniffer
The methodology behind the ECLIF-X campaign involves two aircraft flying in tandem at cruising altitude. The “emitter” is an Airbus A321XLR test aircraft (registration MSN11058), powered by Pratt & Whitney PW1100G-JM engines. Research reports indicate these engines are equipped with the TALON-X rich-burn combustor, a technology specifically designed to reduce soot emissions. During the tests, the A321XLR is flown with three different types of fuel to compare their respective emission profiles.
Following closely behind is the “sniffer,” DLR’s heavily instrumented Falcon 20E research aircraft. Drawing on over 30 years of atmospheric research expertise, DLR scientists pilot the Falcon 20E directly into the exhaust wake of the A321XLR.
Flying at distances of just 50 to 300 meters, the Falcon 20E captures precise, real-time data on the physical and chemical properties of the emissions before they dissipate.
This proximity allows researchers to analyze the exhaust plume in real-time, providing unprecedented insights into the immediate atmospheric reactions triggered by different fuel blends.
Decoding the “Sticky Seed” Problem
How Contrails Form and Trap Heat
Contrails are line-shaped ice clouds that form when hot, humid engine exhaust mixes with cold, high-altitude air. Depending on atmospheric conditions, these contrails can persist and spread into cirrus clouds that trap outgoing infrared radiation from the Earth. According to industry research, studies suggest that non-CO2 effects could represent anywhere from 35% to roughly two-thirds of aviation’s total accumulated climate impact.
Airbus refers to the microphysics of contrail formation as the “sticky seed” problem. Conventional jet fuel contains aromatic compounds, which are the primary precursors for soot particles during combustion. These soot particles act as the foundational condensation nuclei, or “seeds,” for contrails. Furthermore, even trace amounts of sulphur in jet fuel result in the formation of sulphuric acid. This acid coats the soot particles, making them “sticky” and highly attractive to water vapor.
By utilizing fuels with low aromatics and low sulphur, such as highly refined Sustainable Aviation Fuels (SAF), engines produce significantly fewer soot particles and less sulphuric acid. Fewer seeds mean fewer ice crystals, resulting in contrails that are thinner, shorter-lived, or completely prevented.
Building on Previous Success
The current campaign builds upon the landmark ECLIF3 study, which concluded in 2024. Data from ECLIF3 proved that flying on 100% SAF reduced the number of contrail ice crystals by 56% and cut the overall climate-warming impact of contrails by at least 26% compared to conventional jet fuel.
Regulatory Urgency and Future Operations
EU ETS and NEATS Compliance
The ECLIF-X research arrives at a critical regulatory juncture. As of January 2025, the European Union Emissions Trading System (EU ETS) requires airlines to monitor and report their non-CO2 effects. With the first verified reports due in 2026, the industry faces immediate pressure to understand and quantify these emissions.
The introduction of the EU’s Non-CO2 Aviation Effects Tracking System (NEATS) means airlines are now legally required to track these metrics. Research initiatives like ECLIF-X provide the foundational science necessary to create accurate monitoring, reporting, and verification (MRV) models for the commercial aviation sector.
AirPro News analysis
We view the ECLIF-X campaign as a pivotal transition point for airline operations. Historically, the push for Sustainable Aviation Fuel has been framed almost entirely around lifecycle carbon reduction. However, the empirical data gathered by Airbus and DLR highlights a crucial dual benefit: SAF physically alters the clouds aircraft leave behind.
Beyond fuel certification, this research paves the way for “climate-friendly routing.” As airlines and meteorologists better understand exactly how and when contrails form, flight dispatchers could soon pair clean fuels with tactical flight path adjustments to avoid atmospheric regions prone to persistent contrail formation. This operational shift will likely become a standard practice as regulatory bodies tighten non-CO2 reporting requirements.
Frequently Asked Questions (FAQ)
- What is the ECLIF-X campaign?
ECLIF-X (Emissions and Climate Impact of alternative Fuels – X) is a joint research initiative by Airbus, DLR, and Pratt & Whitney running from 2025 to 2027 to study how fuel composition affects contrail formation. - Why are contrails a problem?
Persistent contrails can spread into cirrus clouds that trap heat in the Earth’s atmosphere. Studies indicate these non-CO2 emissions account for 35% to two-thirds of aviation’s total climate impact. - What is the “sticky seed” problem?
Soot and sulphuric acid from conventional jet fuel create “sticky” particles that attract water vapor, forming the ice crystals that make up contrails. Low-sulphur and low-aromatic fuels reduce these seeds. - When do airlines have to report non-CO2 emissions?
Under the EU ETS, airlines were required to begin monitoring non-CO2 effects in January 2025, with the first verified reports due in 2026.
Sources: Airbus
Photo Credit: Airbus
Sustainable Aviation
SHEIN Expands Sustainable Aviation Fuel Use with DHL Partnership
SHEIN partners with DHL Express to pilot Sustainable Aviation Fuel in air freight, supporting emissions reduction amid market and regulatory challenges.

This article is based on an official press release from SHEIN.
On March 24, 2026, global fashion retailer SHEIN announced a new agreement with DHL Express to utilize the logistics provider’s GoGreen Plus service. This initiative integrates Sustainable Aviation Fuel (SAF) into SHEIN’s international air freight operations, marking another step in the company’s efforts to address lifecycle emissions associated with its supply chain.
According to the official press release, the partnership is designed as an early-stage pilot to help the retailer evaluate economic feasibility, certification frameworks, and operational integration. SHEIN explicitly acknowledges that the immediate emissions impact will be modest relative to its total air transport footprint, reflecting broader constraints in the global SAF market where alternative fuels represent only a fraction of conventional jet fuel supply.
We note that this move builds upon SHEIN’s previous SAF pilot programs initiated in 2025, signaling a continued corporate push to support capacity-building activities and demand signaling, particularly within the rapidly evolving Asia-Pacific (APAC) region.
Expanding SAF Pilots and Logistics Partnerships
The DHL GoGreen Plus Agreement
Under the new agreement, SHEIN will leverage DHL’s GoGreen Plus service, which utilizes an “insetting” approach to reduce Scope 3 greenhouse gas emissions. Rather than fueling specific cargo planes directly with SAF, the fuel is introduced into DHL’s broader aviation network. The resulting lifecycle emissions reductions are then allocated to SHEIN using internationally recognized carbon accounting and certification frameworks.
“Signing the GoGreen Plus agreement with SHEIN marks another important milestone in DHL Express’s commitment to driving the green transformation of air logistics. As a long-term partner in SHEIN’s global logistics network, we are pleased to work together to explore how sustainable aviation fuel can be integrated into their air cargo operations.”
Building on 2025 Initiatives
The DHL partnership is part of a broader, multi-carrier strategy. Industry research highlights that in 2025, SHEIN procured 187.3 tonnes of SAF across 14 Atlas Air charter flights, achieving an estimated emissions reduction of 579.1 tonnes of COâ‚‚ equivalent (tCOâ‚‚e). Furthermore, the company signed a Memorandum of Understanding (MoU) with Lufthansa Cargo in August 2025 to accelerate SAF adoption.
Regionally, SHEIN is also participating in a China-based SAF pilot program organized by China National Aviation Fuel (CNAF) and the Second Research Institute of Civil Aviation of China (CASRI). Through this initiative, the retailer plans to procure an initial batch of SAF from Air China Cargo, utilizing traceability mechanisms to track usage.
“Working with partners such as DHL allows us to better understand how sustainable aviation fuel solutions may be incorporated into air cargo logistics. Initiatives like this are part of SHEIN’s broader efforts to explore how emerging approaches across the aviation sector may contribute to addressing carbon emissions associated with air transport.”
Global Bottlenecks and the Cost of Decarbonization
Production and Pricing Realities
SHEIN’s press release notes that wider adoption of SAF remains constrained by limited production capacity and higher costs. Data from the International Air Transport Association (IATA) released in December 2025 provides stark context for these limitations. According to IATA, global SAF production reached 1.9 million metric tons in 2025. While this doubled the output of 2024, it still represented only 0.6% of total global jet fuel consumption.
Growth is projected to slow slightly in 2026, reaching an estimated 2.4 million metric tons, or roughly 0.8% of global demand. Furthermore, SAF currently trades at two to five times the price of conventional fossil jet fuel. IATA estimates that this premium added approximately $3.6 billion to the aviation industry’s fuel costs in 2025 alone.
Policy Friction
The macroeconomic challenges are compounded by regulatory friction. IATA has publicly criticized certain regional mandates, arguing that they have distorted markets and increased compliance costs without guaranteeing adequate fuel supply.
“SAF production growth fell short of expectations as poorly designed mandates stalled momentum in the fledgling SAF industry… If the objective is to increase SAF production to further the decarbonization of aviation, then they [policymakers] need to learn from failure and work with the airline industry to design incentives that will work.”
The Asia-Pacific Momentum
Regulatory Shifts and Capacity Building
The press release emphasizes strengthening the demand signal for SAF in the Asia-Pacific region through capacity-building activities. Industry data shows that APAC is currently undergoing a massive shift in SAF infrastructure and regulation, transitioning from voluntary goals to concrete mandates.
Singapore implemented a confirmed goal of 1% SAF by 2026, funded by a passenger levy, while Japan is finalizing a 10% SAF mandate by 2030. South Korea, India, and Indonesia are also rolling out blending roadmaps expected to take effect around 2027.
To support this regulatory push, physical infrastructure is scaling up. Neste operates a significantly expanded SAF refinery in Singapore, and Hong Kong-based EcoCeres is expanding into Malaysia. Additionally, in May 2025, the World Economic Forum (WEF) and GenZero launched “Green Fuel Forward,” an initiative specifically designed to scale SAF demand and build regional capacity for aviation decarbonization in APAC, involving major airlines and logistics firms like DHL.
AirPro News analysis
SHEIN’s latest announcement reflects a maturing corporate approach to aviation decarbonization. By explicitly stating that the emissions impact of these early-stage pilots will be “modest,” the company avoids the pitfalls of greenwashing and aligns its messaging with the stark realities of the global SAF market. The reliance on DHL’s GoGreen Plus “book-and-claim” model highlights that, for global shippers, insetting remains the most viable mechanism to participate in the SAF economy without requiring direct physical access to alternative fuels at every origin airport. As APAC mandates like Singapore’s 2026 target take effect, corporate demand signals from high-volume freight users like SHEIN will be critical in justifying the massive capital expenditures required for regional SAF refineries.
Frequently Asked Questions
What is DHL’s GoGreen Plus service?
GoGreen Plus is a service offered by DHL Express that allows customers to reduce the Scope 3 carbon emissions associated with their freight. It uses an “insetting” or “book-and-claim” model, where DHL purchases Sustainable Aviation Fuel (SAF) and introduces it into its broader aviation network, allocating the certified emissions reductions to the participating customer.
How much of global aviation fuel is currently SAF?
According to December 2025 data from the International Air Transport Association (IATA), SAF accounts for only 0.6% of global jet fuel consumption, constrained by limited production capacity and high costs.
Why is SAF more expensive than conventional jet fuel?
SAF is currently two to five times more expensive than conventional fossil jet fuel due to the high costs of feedstock collection, complex refining processes, and a lack of scaled production infrastructure globally.
Sources: SHEIN Press Release
Photo Credit: SHEIN
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