David JC MacKay’s ‘Sustainable Energy Without the Hot Air‘ has justly won plaudits for being the first objective, level-headed assessment of our energy problem. MacKay is that wonderful and rare combination, an articulate physicist. His opening chapter, entitled ‘numbers not adjectives’ crisply summarises the book’s argument: do the maths, then look for the solution. Don’t wang on about how turning off phone chargers will save the world or how nuclear power is colossally expensive. The book is a superb example of the power of clear language, with short, active sentences deftly flinging around some very complex subjects. It’s free to download from Mackay’s site, or you can buy it in hard copy.