Sustainable Energy - Without the Hot Air

About the book

Sustainable Energy - Without the Hot Air is a book by the physicist David J.C. MacKay about the physical scale of energy demand and supply. It works through consumption figures for transport, heating, electricity and industry, then estimates what wind, solar, biomass, nuclear and other sources could contribute. MacKay keeps the units consistent and sets the numbers side by side so readers can see the gap between a comfortable lifestyle and a fully renewable supply.

The method is the book's main feature. MacKay builds rough estimates from published figures and invites readers to substitute their own assumptions. He treats energy as a quantity to be counted and is candid about the uncertainty in each estimate. The prose is direct and often dryly funny, with diagrams and worked examples doing much of the explanatory work.

MacKay wrote with Britain in mind, and many of the land-use and supply figures are specific to that country. The approach travels better than the particular numbers.

How to read it

Read the book as a set of calculations to audit. Keep a pencil nearby and follow the unit conversions, since the argument depends on them. When an estimate looks generous or stingy, note the assumption behind it and test how much the conclusion moves.

The density of figures can slow a first pass. Skim the arithmetic to grasp the shape of the comparison, then return to the tables and worked examples. Chapters are largely self-contained, so a reader can start with the demand side or the supply side according to interest.

Who it suits

This suits readers who want a quantitative grounding in energy debates and are willing to do arithmetic. Students in physics, engineering and environmental policy will find a model of honest estimation. Citizens who tire of vague claims about renewables will appreciate a book that puts numbers on the table and shows its working.

Reading considerations

The figures reflect the data available around 2009, so costs, efficiencies and grid data have moved on; treat the numbers as a method rather than current facts. The British focus limits direct transfer to other countries, and the estimates are deliberately rough. Test the assumptions against newer sources before relying on any single conclusion.