There's a book soon to be published by David J.C. MacKay, a Cambridge University professor, called Sustainable Energy - Without the Hot Air. There's a draft available for free at http://withouthotair.com/. The site has a number of other interesting documents, including a 4-page summary of the book, and a fascinating experiment with mobile phone chargers. There's even a link to a list of all the URLs in his book - very convenient and thoughtful.
I had the pleasure of meeting Prof. MacKay whilst on sabbatical in summer 2007. What struck me most about him (besides the wry British wit which, I'm told, is due to something in the water) was how level-headed he was. This, I think, comes through in his book.
