If there's one book I would encourage people to read on this subject: http://www.withouthotair.com/ http://www.withouthotair.com/ .. written by a Cambridge The

If there's one book I would encourage people to read on this subject: http://www.withouthotair.com/ http://www.withouthotair.com/ .. written by a Cambridge Theoretical Physicist. Free download. It simply puts real numbers against various different ways of getting our energy, and in terms of EROEI (Energy Returned on Energy Invested).