As early as 2020, SWISS and the Lufthansa Group concluded a strategic collaboration with the Swiss cleantech company Synhelion to bring solar aviation fuel to market. This will make SWISS the first airline in the world to purchase Sun-to-Liquid fuel from Synhelion.

“Our team-up with Synhelion is founded on our shared vision to make near carbon-neutral flying in regular flight operations possible through the use of solar fuel,” explained the then SWISS Chief Executive Officer Dieter Vranckx. “We are proud that SWISS will be the first airline in the world to use solar kerosene. By partnering with Synhelion, we are supporting Swiss innovation and are actively pursuing and promoting the development, market introduction and scaling-up of this highly promising technology for producing sustainable fuels”.

"We believe in a globalized world connected by climate-friendly mobility", adds Dr. Philipp Furler, Synhelion’s co-founder and CEO. "Our next-generation renewable solar kerosene is an economically and ecologically viable substitute for fossil fuels. The commitment of SWISS and the Lufthansa Group underlines the aviation sector’s keen interest in our solar fuel."
 

Solar energy – the way to almost carbon-neutral flying

Synhelion has developed a key technology for manufacturing Sustainable Aviation Fuel (SAF) from renewable energy sources. The unique procedure uses solar heat to manufacture syngas which can then be synthesized into renewable solar fuel using standard industrial processes. This sun-to-liquid fuel closes the fuel carbon cycle: when combusted, it will only produce as much CO2 as went into its manufacture. The new fuel thus makes a major contribution to effectively defossilize air transport.
 

A milestone for aviation

2025 marked a milestone for aviation: as the first airline worldwide, SWISS successfully integrated solar fuel into regular flight operations. The starting point was a 190-litre barrel of synthetic crude oil produced at Synhelion’s DAWN production facility. This was delivered to a refinery in northern Germany, where the crude oil produced using solar energy was further processed into certified aviation fuel (Jet A-1). Via Hamburg Airport, the solar fuel was then fed into the existing fuel supply system.

The injected quantity covered around seven percent of the fuel required for a flight between Hamburg and Zurich – seemingly small at first glance, but immense in its significance. This step proves for the first time that solar-based aviation fuel works not only in the laboratory, but also in real-world flight operations. In particular, the seamless integration into existing refinery processes represents a decisive breakthrough. It demonstrates that Synhelion’s technology is compatible with today’s infrastructure – a key prerequisite for rapid scaling and global deployment. A symbolic beginning with the potential to sustainably transform the future of aviation.

Also in 2025, SWISS entered into a partnership with the world’s leading logistics provider Kuehne+Nagel to join forces across several sustainability projects. The focus is on new technologies designed to make the transport sector both more efficient and more sustainable. A key element of the collaboration: from 2027, SWISS and Kuehne+Nagell will source sustainable solar fuel from Synhelion for SWISS WorldCargo freight operations over a period of five years. In doing so, the two companies are sending a clear signal in support of the decarbonisation of logistics – while enabling their customers to measurably and sustainably reduce the CO₂ footprint of their supply chains.

This long-term offtake agreement provides Synhelion with planning certainty for scaling up its solar fuel technology.
 

A look back

In 2024, Synhelion inaugurated the world’s first demonstration plant for the industrial production of solar fuels in Jülich, Germany, which is now in operation. The agreed partnership also includes support from SWISS and the Lufthansa Group for the further development and expansion of Synhelion’s first facility in Germany. From 2027, SWISS will be the launch customer for the first commercial volumes of solar kerosene produced there.

Since 2022, SWISS has also been among Synhelion’s investors. This commitment aims to contribute to reducing CO₂ emissions in Swiss aviation through the use of solar fuels.

The partnership between Synhelion, SWISS, Edelweiss and the Lufthansa Group has been in place since 2020.
 

SWISS assumes a pioneering role in the use of renewable Sustainable Aviation Fuels

For many years, the Lufthansa Group and SWISS have been driving comprehensive CO₂ reduction measures and working together with strong partners to continuously reduce their environmental impact. A key lever in this effort is the consistent expansion of Sustainable Aviation Fuel (SAF), the use of which SWISS will significantly increase in the coming years. However, the limited availability of biogenic fuels makes it clear that additional, scalable solutions are needed to achieve climate targets.

Before solar fuel can be widely used in commercial aviation, further steps are still required. At present, the prerequisites for continuous production and sufficient production capacities are being established, with the aim of market entry from 2027 onwards. Clear regulatory frameworks apply in this context: under the EU Renewable Energy Directive, sustainable synthetic fuels must achieve a reduction in greenhouse gas emissions of at least 70 percent compared with fossil kerosene.

A life-cycle assessment reviewed by an independent body confirms that the fuels produced at Synhelion’s DAWN plant can significantly exceed these requirements. As the next milestone, Synhelion and SWISS are now jointly advancing the sustainability certification of both the production process and the fuel in line with the requirements of the EU directive – a decisive step on the path from a pioneering project to industrial application.
 

About Synhelion

Synhelion produces renewable solar fuels to defossilize the transportation sector. The cleantech company has developed a scalable technology to produce synthetic fuels from solar energy. These solar fuels are nearly CO₂-neutral and fully compatible with today’s global fuel infrastructure and conventional engines. Since the launch of its industrial-scale plant DAWN in 2024, Synhelion has been producing solar jet fuel, diesel, and gasoline and delivering them to its customers. Backed by international partners across various industry and transportation sectors, Synhelion is on a mission to replace fossil fuels with renewable solar fuels. For more information, visit synhelion.com.