Sustainable Energy – Without the Hot Air

Customer Reviews

I’ve just been listening to yet another “news” report pointing out that compact fluorescent light bulbs don’t save much energy because an incandescent light bulb will also heat your house.

Coincidentally I had just read the part of this book dealing with this myth, so I was able to confidently mutter under my breath “true, but only in the winter (when you need the heating) and only if you are heating inefficiently using electricity.”

This book puts real numbers to a lot of hand-waving arguments which are used to justify grandiose claims made for different renewable energy sources or to imply that we could save the world if we all just unplugged our mobile phone chargers. Some of the arguments stand up when the numbers are put in, but many don’t. When you see what the numbers are, it becomes evident how unrealistic and ineffectual many of the proposals are.

Is it worth unplugging a power block when not in use? Can planes be made more efficient? How much space would solar farms or a wind farms need to occupy to meet our energy needs? How much agricultural land would be required for bio-diesel? All these questions (and many more) are answered.

What makes this book really stand out is that it converts energy amounts to comprehensible units (kilowatt-hours per person per day), supplies copious references for the numbers used, and provides the calculations on which the arguments are based. (Detailed calculations are presented in appendices for the math-averse and should be accessible to anybody with a basic knowledge of physics).

Note. Although this book is primarily aimed at a UK audience (energy consumption figures are based upon UK patterns, and land use proposals are related to UK locations), the discussions are of global applicability.

42 of 44 people found the following review helpful
Do the numbers!, March 4, 2009 By  Robert Hargraves (Hanover NH USA) – See all my reviews
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This book is essential for anyone thinking about energy policy. It excels because MacKay does not espouse one specific solution, but rather teaches the reader how to create solutions and evaluate them. He emphasizes that the numbers must add up — total energy production must equal total energy consumption.

In a way the book is very simple. He leads the reader by the hand in estimating the energy requirements of society – transportation, heat, food, gadgets, and so on. He similarly helps you make credible estimates of achievable production from sources such as sunlight, tides, hydro, nuclear, wind, coal, and oil.

Like a good physicist, MacKay is able stand back and estimate these numbers top-down from first principles, with just enough depth to generate numbers that are credible to you and good enough for policy making.

The charts, graphs, tables, and pictures are extensive and clear.

If you have a particularly loved energy source [wind?] or a particularly hated one [coal?] you can “do the numbers” and build your own energy policy. The only requirement is that the numbers add up!