In the preface to this extraordinary book the author states, ‘I am concerned about cutting UK emissions of twaddle – twaddle about sustainable energy’. This is exactly what David Mackay has achieved in a remarkable book that is sure to set the standard for all future debate on energy policy and climate change. Mackay attributes ‘twaddle emission’ to the emotional propensity to quote big, impressive or argument-winning numbers, where numbers are quoted at all, in discussions about our need to ensure security of energy supply and solve climate change. We’re told that ‘huge’ amounts of renewable power are available; however, our current power consumption is already ‘huge’. How do we compare ‘huge’ to ‘huge’? MacKay has highlighted a need for numbers, not adjectives and has delivered a ground breaking, ‘straight talking book about these numbers’.

It shows how to estimate those numbers, and what they depend on. Taking the United Kingdom as an example, it asks first “could Britain live on renewable energy resources alone?” and second “how can a country like Britain make a realistic post-fossil-fuel energy plan that adds up?” It answers these questions in detail, bringing home the size of the changes that society must undergo if sustainable living is to be achieved.  It proves without doubt that it is not going to be easy to make an energy plan that adds up – but that it is possible. A technically precise and readable account which, whilst it cannot answer all the questions, provides a solid framework to help us make well-informed choices, as individuals and more importantly as societies. We simply cannot recommend this book highly enough. 366 pages.