How will we fuel mobility in the future?

A very good question considering the current climate protection goals. And because the answer needs to be carefully thought out – especially when it comes from one of the world’s largest car manufacturers – first a little background: Volkswagen is firmly committed to the Paris climate agreement and intends not only to achieve a neutral carbon balance in the medium term, but also to reduce the carbon footprint of its passenger cars and light commercial vehicle fleet in the short term. The Group is planning to achieve this primarily by using fully or partly electric-powered vehicles … which already half-answers the initial question posed. As for the second half, that is a little more complex: for example, what happens to existing vehicles, the majority of which have conventional drives – and in most cases still have a long service life ahead of them? Will the combustion engine still have a future after all? Fuels from regenerative sources could provide a good answer to this. Both biofuels, which are produced from residues, for example, and e-fuels, which are produced from regenerative sources with the aid of CO₂ and electricity, can contribute significantly to greenhouse gas-neutral mobility. Biofuels are already available on the market and their share could potentially be increased in Europe in the next ten years to 20 to 30 per cent of the on-road energy market.

e-fuels based on hydrogen

Researchers and car manufacturers – for example the Audi and Porsche brands from the Volkswagen Group – are currently working on synthetic fuels based on hydrogen, which can be produced on a climate-neutral basis using Power-to-X technology:

• Using energy from regenerative sources – for example wind or solar power – water is broken down by electrolysis into oxygen (O₂) and hydrogen (H₂).
• In the next step, carbon dioxide (CO₂) – which is generated as a waste product in industrial processes, for example, or is deliberately extracted from the environment – is combined with the hydrogen.
• Possible end products include synthetic diesel, synthetic petrol and synthetic gas.

These synthetic fuels are still produced in very small quantities at the moment, such as in research and pilot projects. For example, Porsche is developing and implementing a pilot project in collaboration with industry partners, which should result in the world’s first integrated and commercial large-scale plant for producing synthetic, climate-neutral fuels: The “Haru Oni” pilot project in Magallanes Province in Chile takes advantage of the excellent wind conditions in southern Chile to produce climate-neutral fuel with the aid of green wind power. The aim is to produce some 130,000 litres of e-fuels here by 2022 and grow capacity to around 55 million litres of e-fuels per year by 2024 with an impressive tenfold increase by 2026.

Is efficiency the key?

Efficiency losses are still high at present owing to the numerous individual steps involved in producing e-fuels. Of the energy used in the process, only around 25 to 30 per cent remains at the end – or even less. In comparison, an electric vehicle converts the energy used into power at a rate of around 70 to 80 per cent. A research project by the Karlsruhe Institute of Technology (KIT) is therefore examining how to substantially increase efficiency in the production chain. Efficiency rates of up to 60 per cent are theoretically possible in this context. A core aspect of the trial system is a new synthetic reactor, which requires significantly less process energy than before.

However, there is also another aspect to consider. The electricity needed to produce regenerative fuels can be generated anywhere – for example, where there is a constant wind blowing. An identically constructed wind turbine generates four times as much electricity annually in the wind bands of the Andes mountains as in the North German lowlands. This location advantage can counterbalance the efficiency disadvantage of energy conversion.

Status: 01.09.2021
© Volkswagen AG