Denmark launches first domestic flight using sustainable aviation fuel

Denmark has launched its first domestic aviation route powered partly by sustainable aviation fuel (SAF), marking a significant milestone in the country's effort to reduce emissions from air travel. The inaugural flight, operated by Norwegian Air Shuttle, departed from Aalborg in northwestern Denmark and landed in Copenhagen using a fuel blend containing roughly 40% sustainable aviation fuel mixed with conventional jet fuel, according to Agence France-Presse. The route is intended to demonstrate how lower-carbon fuels can be introduced into commercial aviation without requiring changes to existing aircraft technology or airport infrastructure.

A step toward greener aviation

Sustainable aviation fuel is produced from renewable or waste-based sources such as used cooking oil and other organic materials, offering a significantly lower lifecycle carbon footprint than conventional fossil-based jet fuel. According to estimates associated with the project, the use of the blended fuel on the Aalborg–Copenhagen route could reduce carbon dioxide emissions by roughly 3,000 to 3,300 tonnes annually. This is obviously a step in the right direction, Alexander Bjørn Hansen, a transport expert at the environmental organisation Council for the Green Transition, told AFP, noting that relatively few commercial routes currently operate with significant SAF blends. The launch forms part of Denmark's broader strategy to reduce transport emissions and transition toward greener aviation. The aviation sector accounts for up to 3% of global carbon dioxide emissions, and the industry increasingly views sustainable aviation fuel as a key pathway to meeting its long-term target of net-zero emissions by 2050.

Government backing helps offset higher costs

Despite its environmental advantages, SAF remains substantially more expensive than conventional aviation fuel. Industry estimates suggest the alternative fuel can cost between two and eight times more than traditional jet fuel, depending on production methods and feedstocks. In Denmark's case, government support has helped offset the price difference and keep airline ticket prices unchanged for passengers. The Aalborg–Copenhagen route was introduced under the Danish government's "Green Aviation in Denmark" strategy, which has allocated around 800 million kroner (approximately $125 million) between 2025 and 2029 to support sustainable aviation initiatives. As part of that programme, Denmark introduced an eco-tax on airline tickets in December 2023, which is expected to average about $16 per ticket by 2030. Revenue from the levy will help fund investments aimed at reducing emissions from the country's domestic aviation sector. It's important to us that we take part in the transition supported by the Danish government, Norwegian Air Shuttle chief executive Geir Karlsen told AFP. The infrastructure is there in Aalborg and the way the Danish government is helping out is a good incentive.

Early test for cleaner aviation fuels

For now, only Aalborg Airport has the infrastructure required to supply aircraft with the 40% SAF blend, meaning the renewable fuel is currently used only on one leg of the route. The sustainable fuel itself is produced from recycled cooking oil collected across European cities, processed in Gothenburg in Sweden and then transported by ship to Aalborg Airport. While the route represents a milestone for Denmark, airline executives caution against overstating its environmental impact. As long as we still have fossil fuel in the tank, it is technically not green, Norwegian's Denmark country manager Sara Neergaard said in remarks reported by AFP. It is certainly more sustainable than before, but since it's not yet possible to fly on 100% SAF, we as a commercial airline cannot market it as green. Current aviation regulations permit a maximum 50% blend of sustainable aviation fuel with conventional jet fuel for safety reasons.

Industry exploring future fuels

Environmental organisations broadly welcomed the initiative but warned that sustainable aviation fuel derived from used cooking oil and biomass may remain limited in supply. We support all measures that can reduce CO2 emissions from aviation, Hansen said. However, the current fuel comes primarily from used cooking oil, which is available in limited quantities. We need to develop other types of fuels as well. The aviation industry is therefore exploring synthetic fuels, or e-fuels, produced using renewable electricity and hydrogen as a potential long-term solution. Such fuels, if produced at scale, could significantly reduce aviation emissions without requiring major changes to aircraft technology.

Ambitions for fossil-free domestic flights

Denmark's broader ambition goes beyond the current experiment. The government has set a target for all domestic flights in the country to operate on fossil-free fuels by 2030, if the technology and fuel supply become commercially viable. The Aalborg–Copenhagen route is therefore being watched closely as an early test case for integrating sustainable aviation fuels into regular airline operations. As production of alternative fuels expands and costs gradually decline, similar initiatives could play an increasingly important role in reducing aviation's environmental impact. For Denmark, the route represents not just a domestic experiment but a signal of how national policy, industry cooperation and technological innovation could reshape the future of air travel.