Sunlight and Air Can Be Transformed Into Green Aircraft Fuel

The Swiss Federal Institute of Technology (ETH Zurich), under direct administration by the Swiss Government, built a plant that can fabricate carbon-neutral liquid fuels from sunlight and air.

The Woman Post | Catalina Mejía Pizano

Listen to this article

The Swiss Federal Institute of Technology (ETH Zurich), which focuses mostly on science, mathematics, technology, and engineering, and is under direct administration by the Swiss Government, built a plant that can fabricate carbon-neutral liquid fuels from sunlight and air. The mentioned technology will then need to be produced at an industrial scale to become competitive.

The aviation sector is a relatively small contributor to total greenhouse emissions. However, the trouble is that it is a fast-growing, fossil-fuel intensive transportation mode. According to Boeing forecasts, aviation demand is expected to grow over the next two decades, at 5% per year until 2034 for passengers and cargo traffic.

According to a study by Grobler and colleagues, commercial aviation emissions’ impact on air quality has been estimated to be responsible for almost 16,000 premature mortalities each year around the world. 

In a recent paper published in the journal Nature, scientists from Zurich and Potsdam explain how the new solar reactor works and describe a policy framework that would place incentives to increase the production of solar kerosene. While scientists agree that carbon-neutral fuels are essential for making aviation and maritime transport sustainable, the plant developed in Zurich can produce synthetic liquid fuels that release as much CO2 during their combustion as was previously extracted from the air for their production. CO2 and water are obtained directly from ambient air and split by using solar energy. The process yields syngas, a blend of hydrogen and carbon monoxide, that is then processed into kerosene, methanol, and other hydrocarbons.


If you are wondering who is leading the team of researchers, Professor of renewable resources at ETH Zurich,  Aldo Steinfeld has led the team that operates the mini solar refinery that is located on the roof of ETH’s Machine Laboratory building in Zurich over the last 24 months. In a recent interview, Steinfeld mentioned: "This plant successfully demonstrates the technical feasibility of the entire thermochemical process for converting sunlight and ambient air into drop-in fuels. The system operates stably under real-world solar conditions and provides a unique platform for further research and development."

But how about the costs of the fuel? Analyses of the process have shown that the fuel would cost  1.20 to 2 euros per liter if produces at an industrial scale. Desert regions are optimal production sites, and according to Johan Lilliestam, who is a group research leader at the Institute for Advanced Sustainability Studies, this technology will help us meet the global demand for jet fuel by using less than one percent of the world’s arid land and without competing with the production of food or livestock feed.  

So is everything in place for merging to these types of fuel? It is important to consider that due to the high initial investment costs, solar fuels will need further political support to enter the market. The study authors believe that the European Union’s existing supporting instruments fall short to stimulate market demand for solar fuels and propose the adoption of a European technology-specific quota system for aviation fuel. Despite the difficulties concerning the high costs to enter the market, the possibility of making aircraft fuel from sunlight and air is already great news!