Using liquid air or nitrogen as an energy carrier, either to store electricity or as a vehicle fuel, isn’t a new idea, but creating a viable and efficient commercial technology to do this has been an elusive goal for many years.

Read more: http://www.theengineer.co.uk/blog/the-engineers-top-10-technologies-of-2011/1011314.article#ixzz1iwzjj0Qa