Tuesday, November 10, 2009

Sustainable Energy - without the hot air

Our son Trevor is in the second year of his masters program at UBC and part of his program includes a course on sustainable energy. During his studies he ran across an amazing book that takes on the whole issue of renewable energy, energy consumption, sustainability and climate change in an amazing way. The book is called "Sustainable Energy - without the hot air" and it is written by David JC MacKay, a professor of natural philosophy in the department of physics in Cambridge University. The book is freely distributed on-line and it can be found here:


I have devoted considerable time to learning about energy issues for the past 10 years or so and I have not found any better resource to get a clear perspective of the problems that we face in the coming years. Dr. MacKay does many important things right in the structure of this book. First, he converts all of our energy usage to a single understandable unit. Rather than talk about litres of gasoline for transportation, GigaJoules of gas for heating and calories for food, he converts all energy usage to kiloWatthours/person/day. This allows a direct comparison of how much energy we use to drive to work vs the amount of energy we use to heat our homes.

Next, he directly compares how much energy we consume from the burning of carbon based fossil fuels to the maximum amount of energy that we can possibly produce from renewable energy techniques. It is very sobering to realize that covering the entire land area of Great Britain with windmills, solar panels, solar hot water systems, tidal barrages and bio-fuel crops won't come close to meeting the current energy needs of its' citizens. This is demonstrated through a painstaking analysis of each energy generation system starting from it's basic physical principles. Then he compares these calculations to the actual performance of existing facilities to show the accuracy of the analysis.

On the plus side, David clearly shows that it is much easier to save a kWh of electricity (or any other form of power) than generate a new one. Clearly conservation and energy efficiency are the most important issues to tackle if we want to preserve some semblance of our society in the coming years. Once again, it is very refreshing to see that these problems are best addressed with basic fundamentals rather than exotic science.

Even more significant, the book clearly connects the serious problems of resource shortages, climate change and economic recession and demonstrates how the problems are best addressed with similar solutions. In fact, Dr. MacKay first intended to write a book about green house gas emissions and climate change but felt that this book might be ignored because of the high level of cynicism that has surrounded these discussions. As a scientist, he freely admits that there is uncertainty in science surrounding CO2 emissions and climate change. Then he proceeds to clearly demonstrate the undeniable link between the release of carbon dioxide from the burning of fossil fuel (probably the most comprehensive and understandable treatment I have read). He then compares our refusal to do anything concrete about climate change due to scientific uncertainty about the details to a motorcyclist who is riding along a treacherously narrow road that travels along the edge of a cliff. If fog blows in and obscures the road, should the rider to speed up because he can no longer see the edge of the cliff?

Lastly and perhaps most importantly, the book is written in a very accessible style. A chapter is devoted to each major issue and the text is written in a conversational style - and with a great sense of humour. The chapters are not cluttered with equations or footnotes which could destroy the smooth flow of ideas. At the end of each chapter there are several paragraphs or even pages that provide the evidence for every statement that has been made in the associated text. And as if that weren't enough, there is another chapter at the end of the book which meticulously covers the technical background of the chapter starting from the first principles of physics.

I truly believe that this book provides the complex reality of energy production and consumption in a manner that allows for informed debate and leads to the level of understanding we desperately need in order to face the enormous problems that lie ahead.

1 comment:

BPK said...

I also enjoyed the David Mackay book and created an online tool based on the calculations within it that enables you to create and share your own energy plan that 'adds up.'

It is freely available at:


Please try it out and let me know any suggestions for improvements if you have time.

My Energy Plan that adds up