CONVERTING ELECTRICITY INTO FUEL
IF GERMANY WANTS TO ACHIEVE ITS CLIMATE PROTECTION GOALS, IT MUST ALSO CONVERT THE TRANSPORT SECTOR ALMOST COMPLETELY TO RENEWABLE ENERGIES. USUALLY, THE FOCUS IS ON DIRECT ELECTRIFICATION OF VEHICLES. BUT WHAT ABOUT E-FUELS? OBTAINED FROM RENEWABLE ELECTRICITY, THEY ARE BECOMING AN INCREASINGLY IMPORTANT COMPONENT OF A SUCCESSFUL ENERGY TRANSITION.
AUTHOR: DR. DAVID BOTHE
Plug instead of fuel nozzle – this is how it looks in practice today when private car owners or companies switch to electric or hybrid vehicles. But the electrification of automobile traffic can also be carried out indirectly via the use of so-called e-fuels. With the help of current-based chemical energy sources, such as synthetic diesel, methane or hydrogen, electrical energy can be converted into chemical energy sources and used in conventional combustion engines.
DEPLOYMENT COSTS BEAT EFFICIENCY
Converting electricity into fuel? In energy policy discussions, e-fuels are often criticized for the enormous amount of energy lost through the additional conversion steps. However, the key criterion for use of renewable energies is ultimately not physical, but economic efficiency: Since renewable energy is by its nature inexhaustible, efficiency is not the key factor. Instead, the essential factor is which energetic utilization path carries the least cost.
The entire supply chain from the energy source and the intermediate storage to the vehicle must always be considered – and we should never forget to consider which technologies gain the acceptance of the population.
EXISTING PATHS FOR NEW ENERGY SOURCES
“Covering the energy demand for more mobility while combating climate change is a major challenge,” proclaims a study published in 2018 by the Austrian Association for Automotive Technology. “Power-to-liquid fuels offer a variety of benefits, including high energy density, good shelf life and ease of use.”
Another benefit: Existing infrastructure and applications for liquid and gaseous energy sources can continue to be used, i.e. the well-established supply of fuel and gas as well as the use of traditional combustion
engines. This partly helps avoid costly and time-consuming expansion in the electricity sector, for example for the temporary storage of renewable energy.
In comparison: Based on energy consumption, the storage volume of gas and liquid fuels available in Germany today corresponds to the battery capacity of more than 23 billion BMW i3 vehicles. Such advantages of e-fuels more than outweigh possible disadvantages due to higher conversion losses.
Dr. David Bothe is the associate director of the business consulting firm Frontier Economics