In this episode of our ‘Sustainability in the Air’ podcast, Sabrina Tekle Krarup Jensen, Head of Strategic Partnerships and Innovation at Copenhagen Airports A/S, speaks with SimpliFlying’s CEO Shashank Nigam about how the airport is navigating some of aviation’s most complex sustainability challenges.
Copenhagen Airports A/S, commonly known as CPH, operates and develops the airports in Copenhagen and Roskilde. CPH has committed to reaching net zero across its scope 1 and scope 2 emissions by 2030, a target it expects to achieve ahead of schedule. CPH is also developing comprehensive plans to address its scope 3 emissions, which present the greatest challenge due to their dependence on external actors across the aviation value chain.
Here are the key highlights of the conversation:
Net zero by 2030 and why scope 3 is the real challenge (4:04)
Future fuels at CPH: SAF, e-fuels, hydrogen and electric aircraft (6:22)
Denmark’s green domestic route with 40% SAF (20:58)
The ALIGHT Project: proving SAF’s air quality benefits and building smart energy systems (25:23)
How battery energy storage is enabling airport electrification and resilience (26:45)
Measuring real world fuel emissions with the FuelTrack campaign (31:12)
Rapid Fire! (38:51)
Keep reading for a detailed overview of the episode.
How CPH is measuring SAF’s real-world impact on communities
In 2023, as part of the European Union-financed ALIGHT project, CPH conducted a sustainable aviation fuel (SAF) measurement campaign that lasted several weeks. A dedicated Scandinavian Airlines (SAS) aircraft was first fuelled with regular Jet A fuel to set the baseline, and was flown between Copenhagen and Stockholm with 3-4 turnarounds daily. The same aircraft was then flown across the same route using a 40% SAF-blend. A mobile laboratory operated by the German Aerospace Centre (DLR) measured the aircraft emissions during landing and taxiing.
The campaign yielded positive results. “We demonstrated a 30% improvement in local air quality, specifically through a reduction in the emission of ultra-fine particles,” Jensen shares.
The airport followed this with the FuelTrack campaign in 2025, which is designed to capture what Jensen describes as “real-world complexity” that laboratory settings cannot replicate. “While laboratories offer controlled conditions, they cannot fully reproduce the operational realities of an airport, including shifting winds, variable temperatures, and the complex mix of fuel blends,” she says.
The campaign collected fuel samples from arriving aircraft and tracked specific aircraft plumes during taxiing. The goal was to understand how variations in fuel chemistry affect emissions. “We wanted to uncover the ‘invisible variability’. Jet fuel varies significantly in aromatic and sulphur content, even within specification limits. Through FuelTrack, we were able to observe these variations both in fuel from arriving aircraft and in the jet fuel uplifted at CPH during the campaign,” Jensen notes.
The research produced a unique dataset that directly links fuel chemistry to tailpipe emissions during day-to-day airport operations. For an airport located in the middle of the city and surrounded by residential areas, this level of insight is significant. It goes beyond regulatory compliance and speaks directly to community concerns about air quality.
4 takeaways from the conversation
1. The airport as ecosystem connector across the SAF value chain
CPH plays a facilitative role in the SAF ecosystem rather than a procuring one. As Jensen explains, SAF supply arrangements sit outside the airport’s direct remit, shaping how it engages with SAF development more broadly.
Within this context, CPH focuses on enabling collaboration across the value chain. This includes supporting multiple SAF initiatives in parallel, from eSAF projects to bio-based SAF pathways, and working alongside producers, airlines, and other stakeholders as these projects evolve.
A key part of this role is sharing operational insight. The airport provides operational data and insights on what it would take to scale SAF, helping project developers and partners understand infrastructure readiness and system requirements. It also seeks to connect actors across the aviation ecosystem, creating opportunities for dialogue between producers, airlines, and other participants as the SAF market continues to evolve.
2. The eSAF financing gap no single actor can close
Despite growing interest in eSAF across Europe, the primary barrier to scale is financial rather than technical, says Jensen. While producers, airlines, and airports are increasingly aligned on the need for synthetic fuels, the economics remain prohibitive.
“The business case is not yet viable, given that eSAF remains eight to ten times more expensive than Jet A-1,” says Jensen.
For producers, this price differential creates a fundamental challenge. Scaling production requires airlines to commit to long-term offtake agreements, often extending ten years or more. At current price levels, however, most offtakers are unable to make those commitments.
CPH has seen this dynamic first-hand through its involvement in several eSAF programs. Initiatives such as Project SkyPower, which sought to bring a European eSAF facility to final investment decision by the end of 2025 in order to enable production by 2030, have illustrated the complexity of moving from ambition to execution, shares Jensen. “It proved to be much more complex than what we initially thought,” she adds.
Jensen is candid about the limits of what airports can do in this context. “I don’t think [the financing for eSAF projects] will come from airports, because the level of funding required is too high.” Instead, she points to coordinated action by states and EU institutions as critical to supporting domestic markets while ensuring a level playing field across countries.
3. Denmark’s green domestic route
In her 2022 New Year’s address, Danish Prime Minister Mette Frederiksen set an ambitious goal that by 2025, Danes should be able to “fly green” on a domestic route. Within the aviation industry, Jensen says, the announcement sparked both enthusiasm and concern.
What followed was a prolonged period of dialogue between government and industry to align ambition with what was technically and operationally possible. Eventually, a tender was issued by the government, which was won by Norwegian Air Lines. The airline proposed a model for a green domestic route operating with a 40% SAF blend. Following a year’s delay, the route is now expected to launch in March 2026 between Aalborg and Copenhagen.
The central challenge was not the SAF blend itself, but how the fuel is accounted for and delivered. “The Danish government insisted that the green domestic route be demonstrated using a drop-for-drop principle, meaning that the specific aircraft flying the route must be fuelled directly with SAF,” Jensen explains. In practice, this rules out the use of the mass balance principle and, by extension, excludes the hydrant system, and even the book-and-claim method.
Under a mass balance model, SAF would be supplied through the airport’s existing hydrant infrastructure and allocated across multiple flights instead of being delivered to a specific aircraft. By contrast, the drop-for-drop approach requires SAF to be transported by truck and uplifted directly into the aircraft operating the green route.
As Jensen sees it, the method of allocating SAF to individual flights does not change the underlying outcome. “From a climate perspective, it makes no difference whether the fuel is used by a single aircraft or multiple aircraft,” in her view, “using the mass balance principle will not harm the climate at all.”
While both approaches result in SAF entering the fuel system, a hydrant-based model would be far easier to manage in a busy airport, Jensen adds. Moreover, expanding the green domestic aviation more broadly via the drop-for-drop model would be far more complex. Even so, CPH welcomes the initiative and views the route as a valuable learning opportunity to test SAF operations.
4. Battery storage systems and the infrastructure for electrification
As part of the ALIGHT project, CPH has installed a battery energy storage system airside. Jensen describes it as being “the size of 18 refrigerators,” and capable of storing low-cost, renewable energy during periods of high production from sources such as solar and wind, and deploying it when the grid is more carbon-intensive or electricity prices peak.
It also supports the airport’s broader electrification efforts. “As we transition to more electric ground support equipment and prepare for electric aviation, we need some kind of buffer to manage the massive power spikes that will follow,” Jensen explains. The battery system helps smooth these demand peaks, reducing strain on grid connections.
The process of installing the system has also provided the airport with practical insights. These include safety and compliance considerations, the configuration of energy management systems, and the importance of a holistic approach to integration. These lessons will feed into a replication toolbox that will be publicly available to other airports through the ALIGHT project, allowing them to draw on CPH’s experience when planning similar installations.
For Jensen, the approach reflects a clear-eyed view of how aviation decarbonisation will progress. “The sustainable transition of aviation cannot be achieved by any single industry actor alone,” she says. CPH’s focus on infrastructure readiness and shared learning underscores a model of transition built on coordination, not isolated efforts.
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