July 2019 – Against the backdrop of climate change, gasoline and diesel vehicles are being increasingly placed on the defensive. E-fuels are also available as an alternative to the celebrated – but not entirely uncriticized – electromobility. What lies behind these synthetic fuels and how could they benefit the world economy as a whole?
An idea does not necessarily have to be new in order to be innovative. The foundations of modern e-fuels were laid almost 100 years ago. The German chemists Franz Fischer and Hans Tropsch were researching alongside one another at the Kaiser Wilhelm Institute for Coal Research in Mülheim an der Ruhr. The synthesis they discovered bears their name: the Fischer-Tropsch process.
Today, a good century later, the names Fischer and Tropsch are again on everyone's lips. The reason for this is clear: the world is looking for a solution to the rising global carbon dioxide emissions and the resulting climate change. Whether it be on roads, water or in the air, the transport sector is a major contributor to global warming. Classic gasoline and diesel engines are becoming increasingly maligned. The great hope for advocates of climate protection now rests in electromobility – without questioning how climate-friendly the electricity produced for electric cars actually is, or alone how much carbon dioxide is pumped into the environment during production of the necessary batteries.
Worldwide limit values of selected countries and the EU
To use modern technical jargon, Fischer and Tropsch's old idea promises true climate neutrality; its technical basis is electrolysis, which splits water into its constituents oxygen and hydrogen. Further processes chemically bind the hydrogen obtained in this way to carbon using carbon dioxide. The new compound creates a synthetic liquid fuel. During production, the same amount of carbon dioxide is removed from the environment as is later released during combustion. And if the electricity required for electrolysis comes from renewable sources such as wind or sun, then it is a 100 percent climate-neutral fuel. Engineers generally refer to the technology for storing renewable electricity using synthetic fuels (electricity to liquid/power-to-liquids and electricity to gas/power-to-gas) as power-to-X.
Members of the "Power to X Alliance" interest group include industry leaders such as Audi AG and BP Europe SE, alongside canny newcomers such as GP Joule GmbH from Reußenköge in North Frisia, Germany. Founded in 2009 with the conviction that 100 percent renewable energy supply is feasible, GP Joule is now, in its own words, "a system provider for integrated energy solutions from sun, wind and biomass as well as a partner at the supply level for electricity, heat, hydrogen and electromobility". The medium-sized group of companies employs more than 200 people in Germany, Europe and North America.
GP Joule is also focusing on synthetic fuels with its newly launched e-Farm initiative. "It's the largest green hydrogen mobility project in Germany to date. It will enable us to implement a hydrogen infrastructure in the group – from generation, to processing to fleet utilization," says André Steinau, a management consultant at GP Joule.
Regional wind power will be used to generate hydrogen, which can then be used for refueling at two hydrogen filling stations in Husum and Niebüll. At the start of the project, two fuel cell buses will be purchased for regular bus services and five cars powered by fuel cells. More are set to follow.
Maximum PtX share of selected sectors in 2050
At present, classic liquid fuels still provide around 98 percent of propulsion energy for transport and more than 20 percent of heating energy in Germany. Of around 46 million German cars, only 200,000 are currently powered by electric or hybrid drives; the rest roll the streets with combustion engines. Moreover, this fleet cannot be converted to other technologies as quickly as the German government's climate protection goals require. With e-fuels, on the other hand, no technology exchange is required. According to proponents of e-fuels, all existing infrastructures can continue to be used, i.e. pipelines, tank farms and filling stations. This would give a great boost to the transformation of the energy system: No one would have to build a completely new supply system from scratch. "This is a key argument for market development and its costs," says Nils Driemeyer, Global Head Renewable Energy at Hamburg Commercial Bank.
Consumers can continue to use the green fuels in their proven and already used combustion engines and heaters, but in a climate-neutral way. "They are thus a fast and efficient lever for reducing CO2 emissions," says Kurt-Christian Scheel, Managing Director of the German Association of the Automotive Industry.
E-fuels can do almost everything that is important in the energy world: power cars, trucks and especially ships and airplanes over long distances and fuel boilers and power-generation turbines. Gaseous or liquid e-fuels can also be used as raw materials in industry: as hydrogen, methane and synthetic gasoline and diesel fuels including kerosene.
According to the result of a study on energy system transformation published by the German Energy Agency (dena) in the summer of 2018, e-fuels will be able to cover a demand of 150 to 900 terawatt hours (TWh) in Germany alone by 2050 – above all in areas that cannot be freed from emissions through the direct use of renewable electricity or can only be freed with difficulty.
Since e-fuels can be stored and transported easily, they can be produced more cheaply in sunny and windy regions of the world than in Germany or other European countries; North Africa or the Middle East are just two examples. One kilowatt hour of renewable electricity costs a good six cents in Germany, but only three to four cents in North Africa. "The number of countries or locations that could be considered for the production of e-fuels is definitely higher than the number of oil-exporting countries," says Alexander Tremmel, Project Manager in the Energy Systems Technology Field at Siemens AG, Corporate Technology.
EU Climate Commissioner Miguel Arias Cañete also believes in synthetic fuels: "The production of renewable energy offers a wide range of opportunities for 'green growth' and increased employment in Europe. We spend almost one billion euros per day on oil. Replacing these imports with domestically produced energy is an important way to revive our own economy." But the EU Commissioner also knows: "The specific role of e-fuels compared to other forms of alternative energy will depend on technology development, grid integration and costs."
The latter in particular are still far too high for a real market breakthrough; the most critical estimates range from 4.50 euros to even more per liter. As a scientist, Tremmel is more optimistic and believes that e-fuel production costs of around one euro per liter are feasible within the next five to ten years. A prerequisite for this, however, is the roll-out of the technology, which so far has not progressed much beyond the experimental stage in Germany.
The World Energy Council is also lending both courage and impetus to German climate protection and economic policy courage with its studies. The results of the study "International Aspects of a Power-to-X Roadmap" that he commissioned are clear: If Germany wants to actively shape energy system transformation, synthetic fuels and combustibles from renewable electricity must become the third pillar of a global transformation – alongside energy efficiency and the direct use of electricity from renewable energies.
Carsten Rolle, Managing Director of the World Energy Council – Germany and Head of Energy and Climate Policy at the Federation of German Industries (BDI), calls for state subsidies to achieve this major goal: "As with all major new technologies, the production and use of e-fuels needs a push. In the past this was the case with renewable energies; it was also the case with fossil technologies." He says that only when the necessary awareness is created can the industry take the other steps, such as the construction of pilot and demonstration projects or industrial production.