Nature shows the way. In ecological systems, CO2 released into the atmosphere is bound and recycled. This natural cycle has inspired Audi. A key to CO2-neutral mobility: the Audi e-gas plant.
The Audi e-gas project is all about sustainability – not only with regard to the car itself, but also the entire chain of energy sources. With the Audi e-gas plant, Audi is taking a decisive step towards CO2-neutral mobility and looking beyond corporate boundaries. Because power-to-gas technology links the electricity grid with the natural gas network. Audi is the first manufacturer worldwide to introduce this innovative process. The end products are hydrogen and Audi e-gas, a synthetic natural gas.
“We support this technology as power-to-gas can become a milestone in the history of automobility in Germany. Because this form of mobility is CO2-neutral”, explained Peter Altmaier, German Federal Minister for the Environment, at the opening of the Audi e-gas plant in Werlte in June of this year, thus sharing the view of Heinz Hollerweger, Head of Total Vehicle Development.
The power-to-gas plant in Werlte produces the eco-friendly Audi e-gas in two stages. First, surplus electricity from renewable energy sources is used to split water into oxygen (O2) and hydrogen (H2) in three electrolysers. A process known as electrolysis.
The second stage, methanisation, combines hydrogen (H2) and carbon dioxide (CO2). The reaction produces renewable synthetic methane (CH4): Audi e-gas.
Driving with Audi e-gas generates only as much CO2 as was previously bound by the plant. It is practically identical to fossil-based natural gas and is fed into the existing natural gas network and distributed to the filling stations. The amount of Audi e-gas produced annually, namely around 1,000 metric tons, is enough to power some 1,500 Audi A3 Sportback g-tron cars, each of which can clock up 15,000 kilometres of CO2-neutral driving.
The Audi e-gas project is the first step towards achieving the goal of sustainable CO2-neutral mobility. But e-gas production is not the only aspect of the project. As soon as there is a functioning infrastructure, the power-to-gas plant will also be able to provide the hydrogen produced through electrolysis to power fuel-cell cars. In addition, the e-gas can also be converted back into electricity and can therefore also be used for intermediate storage of renewable energies.
Reiner Mangold, Head of Sustainable Product Development, describes the special nature of the plant as follows: “Audi is the only manufacturer worldwide with such innovative technology. Research into synthetic eco-friendly fuels is part of our vigorous Audi e-fuels strategy.” Besides the e-gas project, the e-fuels strategy also includes e-ethanol and e-diesel. Both fuels are produced with the aid of microorganisms at a research facility in New Mexico. The only basic materials required for this are water, sunlight and carbon dioxide.