Biofuels have issues – and like a sulky mate, hit us repeatedly with contradictory demands or unanswerable questions. If we plant fuel crops everywhere, their growth leaches the soil and their use as an oil/fuel substitute deprives the starving billions of food. This intractable reality seems to leave us nowhere to go. Audi, and its partner Joule (in America) are promoting a non-fossil compressed natural gas made by a process that mimics photosynthesis, and that pulls CO2 from the atmosphere as part of its makeup. Audi has a clever plan, as presented at the Society of Automotive Engineers (SAE) 2013 Government/Industry Meeting. In Europe, SolarFuel will provide motive power for the first Audi g-tron compressed natural gas (CNG) vehicles. Joule explains its process: “Unlike fuels produced from agricultural or algal biomass, Joule produces fuels directly and continuously from sunlight and waste CO2 – avoiding costly raw materials, pretreatment and downstream processing. The company’s Helioculture™ platform uses photosynthetic microorganisms as living catalysts to produce fuel, not …