The aviation industry frequently comes under fire for its negative environmental impact. Synthetic fuel company Synhelion is helping redress the balance by making synthetic fuel using solar energy.
Having spun out from the Swiss Federal Institute of Technology in 2016, the company has developed unique technology that uses concentrated solar heat to turn carbon dioxide (CO2 ) into aviation fuel. The fuel is fully compatible with existing global fuel infrastructure and could contribute to a zero-emission future for the aviation industry.
We speak to company founders and CEOs Gianluca Ambrosetti and Philipp Furler to find out how the fuels are produced and discuss their key benefits over other alternative fuels currently on the market.
Frankie Youd (FY): How does your process create synthetic fuel produced from solar energy?
Philipp Furler (PF): We use solar heat to convert CO2 into synthetic fuels that we call solar fuels. When the sun is shining, solar radiation is reflected by a mirror field, concentrated onto a receiver, and converted into high-temperature process heat.
The generated heat is fed to the thermochemical reactor that turns CO2 and H2O into syngas, a mixture of H2 and CO2. The syngas is then processed into fuels by standard gas-to-liquids technology. We can produce any type of hydrocarbon fuel: jet fuel, gasoline, diesel.
Why was solar selected rather than another means of producing the fuel?
Gianluca Ambrosetti (GA): It’s clean and climate friendly, it’s efficient and it works. Fuel production and many other industrial processes require ultra-high-temperature process heat to function in the first place or to reach viable efficiency.
Up until now these temperatures could only be generated by burning fossil fuels. With our solar technology, we can generate solar process heat at temperatures beyond 1’500°C, which is about three times higher than what other state-of-the-art concentrated solar technology offers. That means we can now efficiently power these industrial processes with solar energy.
When is it planned to be available?
PF: In 2022 we’re building the world’s first industrial-scale solar fuel production plant at Brainergy Park Jülich in Germany. Our solar jet fuel production will begin there in 2023.
By 2025 we’re targeting a commercial production capacity of two million litres of fuel per year and by 2030, we plan to ramp up production capacity to produce 875 million litres of solar fuel, enough to cover about half of Switzerland’s jet fuel consumption.
What are the key benefits of this synthetic fuel over others?
PF: Using solar heat directly, rather than photovoltaic or wind energy, means our process consists of a minimal number of conversion steps. The result is a higher energy conversion efficiency than other synthetic fuel technologies.
Another advantage is that thermal energy storage is much cheaper and environmentally friendlier than battery storage. Thanks to our thermal energy storage, we can produce fuel around the clock, which guarantees a high plant uptime. Altogether this means we’ll be able to offer our solar fuels at competitive prices with fossil fuels.
GA: Our technology doesn’t compete for arable land with agricultural demand and has a smaller land footprint than other synthetic fuel technologies. It requires desertic areas with plenty of sunshine. Such land is available in many regions around the globe. This means that it’s possible to scale our technology to cover global fuel demand, increasing access to clean energy and reducing energy dependence.
Do you think that switching to these types of fuels will be key for the industry on its decarbonisation journey?
PF: We need a range of technologies to decarbonise transport. Electrification won’t do this job alone. The aviation sector for instance requires energy carriers with a very high energy density and electric batteries are still far away from reaching the required energy densities.
However, liquid drop-in fuels can, and they can be used without any adjustments to the existing global fuel infrastructure. Engines won’t need to be refitted. No new aircraft will need building. Airports won’t have to adjust their processes.
GA: We also need to acknowledge the urgency of the climate crisis. We require solutions that can improve the status quo in the next few years and that can also deliver on the ambition to become a net zero industry.
Our near-term approach uses a mix of CO2, water, and methane. It already substantially reduces carbon emissions compared to fossil fuels. Our longer-term solution, which has already been proven under real field conditions at ETH Zurich in Switzerland, uses CO2 and water exclusively. This ultra-clean solar fuel closes the carbon cycle of transport. It uses the same amount of CO2 for fuel production as is released during fuel combustion.
What does the future hold for the industry considering its current decarbonisation strategies and initiatives such as the ones mentioned at COP26?
GA: Looking at the aviation sector, there are three types of technologies that are currently being researched and developed to achieve climate-neutrality: electrification, hydrogen technology and synthetic fuels. We consider synthetic fuels to be the most promising and suitable path. The aviation industry, which calls them Sustainable Aviation Fuels (SAF), counts on them to reach net zero in the future.
To establish a functioning market for synthetic fuels, governments must set the right incentives. The first small plants will not yet be profitable. Only through economies of scale will large-scale plants be able to produce at competitive prices. Politics can support the commercialisation. Defining binding quotas that increase over the years for the use of SAF in aviation is definitely a good start.
PF: The latest EU “Fit for 55” plan sets out a mandatory, successively increasing blending quota of SAF for airlines: 2% in 2025, 5% in 2030, 20% in 2035, 32% in 2040, and 63% in 2050. Aircraft are currently only allowed to operate on a 50% blend of SAF and conventional jet fuel. However, aircraft and engine manufacturers are performing research to certify 100% SAF use.