E-fuels play an important role as a more environmentally friendly alternative to crude oil, natural gas and coal. The term “Fuels” is English for fuels, the “E” stands for renewable electricity. Because such fuels are produced with the help of regenerative energy. In terms of their chemical structures and basic properties, they do not differ from conventional diesel or petrol made from petroleum. In practice, they should be used to propel aircraft and ships, they serve as raw materials for the chemical industry and can store energy. But how environmentally friendly is the production of these synthetic fuels really?
The Institute for Energy and Environmental Research (Ifeu) investigated this in a study commissioned by the Federal Environment Agency – with surprising results. Production is associated with considerable environmental impacts: the air, water and soil are heavily polluted.
In the study, around 60 different production and transport paths were analyzed in order to determine the environmental impact of e-fuels. In one model, for example, diesel was produced using electricity from photovoltaic systems in Saudi Arabia and CO2 from cement plants there and transported to Germany by tanker. In another, the production of methanol in Sweden from residual forest wood and with electricity from hydropower was analyzed. The production of hydrogen in Germany and the production of biomethane from agricultural raw materials, such as corn, were also considered.
One finding: the production of power generation systems, such as wind turbines or photovoltaic systems, make a significant contribution to the environmental impact of synthetic fuels, as Daniel Münter, one of the authors of the study, explains. Although the global warming potential is low if 100 percent renewable energies are used, there are other negative environmental effects: Among other things, acidification, fine dust pollution and ozone-depleting substances are released. “The production of synthetic fuels does worse in terms of environmental pollution than the production of fossil fuels such as natural gas and diesel,” says Münter. “This is mainly due to loads from the power generation facilities”.
However, this does not mean that e-fuels are generally worse and have to be left out: “You should have a look at the production process and its environmental impact from the outset”. It is clear that modern societies have to move away from fossil fuels, says Münter. The only question is how this can be implemented in such a way that the environment is not additionally polluted.
In addition, synthetic fuel should be used consciously. It is essential in many areas, such as aviation and shipping, but not in mobility: “The use of synthetic fuels is not efficient here, the energy consumption for synthetic diesel and methanol is too high to be used as fuel on the road to waste, ”said Münter. “Wherever electricity can be used directly, it makes more sense than the detour via e-fuels”.
The production of green hydrogen is making progress, and it should soon enable the climate-neutral economy. But this also requires green carbon, which can be extracted from the air. Inventors around the world are currently working on this –