12 of 13 people found the following review helpful
A stimulating, numerate guide to alternative energy,
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This review is from: Sustainable Energy - Without the Hot Air (Paperback)
Prof MacKay's starting point is that there is a great deal of vague flummery talked about energy production and consumption. It is easy to make vague claims of "huge" potential green sources or to obsess over what turn out to be very minor energy savings. His goal in this book is to have a hard-nosed discussion of real numbers, so that there can be a more sensible discussion of options. He avoids making explicit recommendations, but his one continual plea is that we create a plan that "adds up" rather than merely reflecting wishful thinking. The world currently consumes enormous quantities of fossil fuel, so any viable alternative plan also has to deal with very large numbers, either as savings or as alternate sources.
MacKay writes in a very readable and entertaining style. But he is also very careful to explain his numbers and to build his scenarios from the ground up. I found his analyses convincing and stimulating. Sometimes more detailed or more mathematical analysis is pushed off to supplementary appendices, but those are also well worth reading.
I learned many things. One key factor I hadn't appreciated was the enormous land areas required for renewable sources, such as wind, solar, biofuel, or geothermal to make a substantial difference. For example, MacKay calculates that it would probably require 10% of the UK's surface to be dedicated to wind farms in order to make a significant contribution to the UK's current energy needs. Even larger areas are required to generate meaningful quantities of biofuel. If an area the size of Africa were dedicated to growing biofuel, that might only replace a third of current world oil needs. But MacKay also points out there may be places where building vast energy farms makes sense. For example, a 20,000 square km solar power farm in the Sahara could be one way to meet the UK's energy needs.
MacKay explains how technologies such as electric cars or heat pumps reduce energy needs, independent of how the electricity is generated. He shows us that because electric motors are extremely efficient, burning oil in a central power plant and using the electricity to run an electric car actually requires much less energy than traditional cars. Similarly, he shows how using a central electric power station to power home heat pumps is a significantly more efficient way to heat houses than burning gas or oil at the house. (I had definitely not understood this before!) MacKay would prefer we use green technology to create the electric power, but it is interesting that even using fossil fuel power stations, electric cars and heat pumps still reduce overall fossil fuel consumption.
In his concluding chapters, MacKay outlines several possible plans that "add up". All of them have significant negatives, either through reliance on nuclear power, or enormous environmental impact, or enormous expense. He doesn't pick a winner from among these options, but he emphasizes that we need to chose a plan rather than simply saying "no" to every possible option.
Regardless of whether you agree with Prof Mackay's goal of shifting to alternative energy supplies, this book is definitely worth reading. MacKay succeeds admirably in explaining the raw numbers, so we can see what realistic energy choices are available.
Having read this book (and having it available as a reference) I now feel much better equipped to read the plethora of ideas, plans, suggestions, trivia, wishful thinking and occasional good sense that circulate around energy policy. MacKay is right that numbers matter, and plans need to add up!