You can download a pdf version (or purchase a hard copy) of a very useful energy reference book by Professor MacKay of the Department of Physics, Cambridge University from the following website: http://www.withouthotair.com.
The text which includes many informative diagrams and tabulations analyses whether a country like the UK could live on its renewable energy sources. Given the diffuse nature of this energy compared to that of fossil fuels, the book points out that large tracts of land would be required if renewables were to meet current energy demands. This leads the author to conclude
that it will be necessary to reduce energy consumption.
The book provides the energy numbers for all kinds of devices and activites such as driving and flying, as well as those for imported manufactured products which as previously noted, are commonly omitted when estimating a carbon footprint. It also examine ways in which the gap between production by renewables and energy demand could be managed.
