Synthetic Fuels Synthetic Fuel: "A Supplement to E-mobility, But Not an Alternative"
Synthetic fuels, known as e-fuels, are increasingly being mentioned as an alternative to electro-mobility. A new study has now examined their possible applications and costs.
Increasing climate protection requirements, as agreed to in the coalition agreement of the CDU/CSU and the SPD, call for the targeted use of based synthetic fuels based on electric power and the phasing out of fossil oil and gas in the long term. In order to reduce the current very high costs for the production of such electricity-based energy sources, investments have to be made in the construction of generation plants at an early stage and continuously, the two think tanks Agora Energiewende (Energy Transition) and Agora Verkehrswende (Traffic Transition) recommend. According to a joint analysis of the two initiatives, this involves an "international 100-gigawatt challenge" and an "oil and gas consensus".
In the long term, gas produced from renewable electricity will be needed to return electricity to the grid. It serves as a storage for climate-neutral electricity and returns the energy if wind and photovoltaics are temporarily unable to provide enough energy ("dark lows"). Apart from the direct consumption of renewable energy, synthetic gas or synthetically produced liquid fuel is also indispensable to complement the extensive decarbonization efforts required in transportation, industry and heat supply.
However, synthetic fuels should only be used in a very targeted way — "like Joker in a card game," says Patrick Graichen, Director of Agora Energiewende. He refers to areas, where they offer benefits and cannot be replaced by existing assets. “This concerns in particular aviation and shipping, chemical raw materials and high-temperature heat. However, if we can use the electricity directly, for example in the building sector, we should do so. This will always be cheaper and more efficient than the use of synthetic fuels."
Synthetic Fuel Is Not a Miracle Diesel
Christian Hochfeld, Director of Agora Verkehrswende, thwarts hopes that synthetic fuels for passenger cars with combustion engines offer a bridge into the age of climate neutrality. “A synthetically fueled combustion vehicle requires around five times as much electricity for the same distance as a battery-powered electric car. This is not only extremely inefficient but also expensive. Synthetic fuel is therefore anything but a 'miracle diesel'," says Hochfeld. "It can complement e-mobility, but it is not an alternative to it."
Synthetic fuels are produced from electrical energy. For this purpose, hydrogen produced by electrolysis and then methane or liquid fuel is produced by adding carbon molecules. The advantages of synthetic fuels compared to direct electricity use lie in their high energy density, their good storage capacity and the distribution infrastructure, some of which is already in place. However, its production involves high energy conversion losses: From 100 kilowatt hours of electricity, only 13 kilowatt hours remain to be used for locomotion in a combustion car.
According to the study of the two think tanks, the surplus electricity produced by solar and wind farms in Germany in the short and medium term "does not provide a sufficient basis for a cost-effective operation" of synthetic fuel plants. Instead, the electricity for the production of synthetic fuels has to be generated in specially constructed plants. Therefore, synthetic fuel has to bear the full costs of renewable energy generation. That is why one kilowatt hour of this energy, starting at 20 to 30 euro cents, is around five times as expensive as fossil diesel fuel, for example.
Achieving Long Term Cost Reduction
However, long-term cost reductions can be achieved if synthetic fuels are produced where renewable electricity can be produced at particularly low cost over many hours a year, for example in Morocco, Saudi Arabia or in wind farms in the North Sea or Baltic Sea. This is the result of the second part of the study, which was carried out by the international consulting firm Frontier Economics on behalf of Agora Energiewende and Agora Verkehrswende.
The cost of synthetic gas imported from North Africa could then fall to around 10 cents per kilowatt hour by the middle of the century. If synthetic fuels are imported to help reduce emissions in Germany, special attention must be paid to ensuring that production in the countries of origin meets sustainability criteria.
Among other things, it must be ensured that the renewable electricity required for the synthetic energy sources is added to the energy production and, if necessary, carbon emissions from this additional energy output is removed from the air. Furthermore, energy supply and climate protection strategies in the countries of origin must not be compromised.
Agora Energiewende and Agora Verkehrswende warn against replacing fossil oil and gas with synthetic fuels. The conditions for the phasing out of fossil fuels and the introduction of synthetic fuels should be agreed in an oil and gas consensus between politics and industry.
This article was first published by next-mobility.