Review: "Sustainable Energy - Without the hot air"
"Sustainable Energy - Without the hot air" - David Mackay.
This book is is a practical, hands-on exploration of whether or not the human race can survive on "renewables". MacKay seeks to take the "hot air" out of energy politics, and instead determine "what adds up", by using back-of-the-envelope math to estimate and compare generation echnologies vs consumption patterns.
In the first section, alternating chapters each deal with either an element of energy consumption, or a method of power generation. Using publicly available knowledge and simple arithmatic, Mckay arrives at numerical estimates of power usage and generation. An ongoing tally is kept of generation potential vs energy usage, and the suspense grows: Is it possible to generate enough renewable energy to power our society?
It should come as no surprise that it turns out that we aren't able to generate enough renewable energy to power our energy-hungry society. This brings us to the second section, which explores opportunities and efficiencies to reduce our energy consumption.
This chapter explores personal energy consumption, energy transmission, transport practices, and building methods, looking at each, and how they can be modified, or re-engineered to reduce energy consumption. He quantifies where energy can be saved, how much energy can be saved, and shows us how to do it. He adjusts his ongoing tally, and slowly, the gap between consumption and generation doesn't seem insurmountable.
Mackay is critical of initiatives that stress "Everyone doing a little bit", emphasizing that if everyone does a little, we'll only save a little. He sees little value in micromanaging personal power consumption, but big benefits in making changes to the way we do things as a society. In Mackay's view, we should be focusing on implementing efficient house heating, not fussing over the making sure we unplug cell-phone chargers.
The final third of the book is a technical appendix, going into great detail on the math and technical specifics of topics discussed in previous chapters. This chapter would probably not be of interest to anyone but engineers, and I did not read it myself.
The math done in this book is done in broad strokes, with rounded estimates. Mackay's approach is more about comparison than about accuracy, and some may may find room for criticism here. This willful imprecision is fundamental to the author's method, which isn't to quantify power usage to the 10th decimal point, but instead to show, comparatively, how different generation methods measure up to each other, and our consumption. In the end, all that is really required is order-of-magnitude accuracy. Most importantly, by walking the reader through his calculations, the author empowers the reader to "roll their own", using their own data sources.
This book is a masterpiece, and it is with great reluctance that I criticize it. Nonetheless, a few points stand out:
1) The author focuses on operational output of energy sources, but inconsistently acknowledges the constraints of up-front investment or scalability limits. While this conscious omission may be necessitated by his methodology, I think it is a significant fudge, and one that could result in misleading conclusions. Hopefully, in a future release, the author will expand his framework to include these considerations in a consistent manner.
2) Additionally, I took issue with the chapter on Nuclear power. MacKay focuses disproportionately on prototype nuclear technologies such as breeder reactors and refining Uranium from seawater. While he does delineate the prototype technologies from what's currently available, his emphasis on them leaves the reader with a skewed impression of the energy generation potential of Nuclear. Given the glacial pace of nuclear innovation, it is not likely these technologies will see primetime in the forseeable future. It's good to touch on what's possible, but it shouldn't eclipse what's practical, particularly in a book that emphasizes a realistic approach.
Mackay makes many valuable insights throughout his book. One example is his observation that nuclear waste is comparatively small, making it a lot easier to manage than the waste output of coal.
The book is well layed out, with plenty of graphs and diagrams to support data comparisons and assist with explanations.
This isn't a feel good read about the possibilities of technology. This technical book for those who are serious about understanding the underlying economics of energy usage. Nonetheless, it is far from a dry read, is engaging, and hard to put down. Hopefully it will gain the attention of policy makers, for it would be an invaluable tool in their hands. On an individual level, there is still a great deal of value in helping understand the breakdown of personal energy usage, and how it can be curtailed.
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