Someone at work put me onto this: Sustainable Energy - Without the Hot Air. It's a website and a book (free download or a print version is coming out). Dealing with the current debate on reducing energy use and what sort of energy supply we should use in the UK, it seems to have some hard numbers to work from. Or at least I hope so: the author is a Professor at Cambridge Uni.Here's one of the slides on the site (quite similar to some in 'An Inconvenient Truth'):

AuthorJonathan Clark