To produce “e‑gas” (methane), car manufacturer AUDI requires electricity, water and carbon dioxide. Using “green power”, i.e. from renewable energy sources, hydrogen is procured by the electrolysis of water. Carbon dioxide reacts in a second step with hydrogen via chemical coupling to methane. This synthetic natural gas can be used as a fuel in a standard gas engine. In this process solely climate-neutral oxygen and water are generated as by-products. Since 2013, AUDI operates an industrial plant for the production of ~1,000 tons of “e‑gas” per year in Werlte, Germany. During this process ~2,800 tons of carbon dioxide, provided by a nearby waste biogas plant, are utilized, which equals to the amount of carbon dioxide bound per year by a forest consisting of 220,000 beech trees. The produced synthetic methane can be fed into the existing natural gas grid.