The Independent is running a story about Air Fuels Synthesis Ltd and their process for obtaining petrol from water and air using electricity as energy source.
Tim Fox, head of energy and the environment at the Institution of Mechanical Engineers has seen the process working. Cost of the fuel per litre in energy terms is not stated.
Maybe cheaper to get more concentrated CO2 from gas power stations to help slash rate of carbon emmissions per kwh of energy used or better still get cars to collect their own CO2 output in reusable abosorbers which then be exchanged at petrol stations when you fill up.
I would have thought collecting CO2 from air is always going to remain slow (in industrial process terms) and thus expensive.
A description of their process is on their website.
These sort of potential developments make it all the more important that wind farm projects like Greenwire should have export points near industrial centres so surplus green electricity that cannot be used on the grid, can be used off-grid.