Sustainable energy – how does it add up?

1 June 2010

It is reasonable to claim that people only get interested in energy matters when a crisis is upon us. A crisis is when the lights are about to go out owing to power shortages, or there are queues at the gasoline pumps following difficulties in the oil product supply chain. But now we have a rather different crisis that is set to last much longer than these relatively short-term incidents. This is the realisation that the way we are currently using energy is non-sustainable, both in terms of the depletion of finite natural resources but more importantly owing to its anticipated impact on the world’s climate. Climate change has increasingly grabbed the attention of the world’s media over the past decade and everyone has a view on it.

Whether one believes the majority of climate scientists or not, the precautionary principle and the fact that air pollution from the burning of fossil fuels is certainly responsible for the premature deaths of thousands of people worldwide, argues for the world getting off fossil fuels as soon as possible. Added to this is the likelihood that world oil output will likely soon peak and lack of resources will prevent developing countries following the same route as developed nations have done in energy use. A better way has to be found that is sustainable yet allows sufficient energy to be available to promote economic development.

The problem is that discussions about energy matters inevitably get bogged down by a large amount of dogma and masses of numbers, produced to promote one solution or another. If we are to get off fossil fuels by 2050, as the International Energy Agency (IEA) suggests in some of its scenarios, it seems essential that we must both use energy much more efficiently and develop all of the low greenhouse gas emitting sources as much as possible, including carbon capture and storage. Yet renewable energy advocates continue to claim that it can all be achieved by wind, solar, tides and waves, mixed with significant conservation. And some nuclear advocates continue to disparage the renewable sources, going beyond citing their obvious shortcomings to damning them as completely useless.

It would seem intuitively obvious that a lot of light could be thrown on these debates by referring to agreed numbers. Yet this isn’t as easy as it sounds – the energy business is notorious for a huge number of measuring units, and it is difficult to compare like with like. Energy publications such as the annual BP Statistical Review contain conversion tables, but it is not easy for anyone but the specialist to make any sense of all the data series that are available.

Enter a Cambridge University physicist, Professor David MacKay, with his book "Sustainable Energy – Without the Hot Air [ISBN 978-0954452933]". He became tired of what he saw as the amount of ridiculous nonsense written about energy matters and spent a few years writing a book that, above all else, tries to put some sound numbers behind the claims for one source of energy or another. The outcome is probably the best book written about energy matters for many years, which will challenge most of any readers’ preconceptions.

It is, however, a somewhat quirky book, which will surprise readers by the demands it puts upon them to maintain the same degree of common sense through all its pages that the author so ably demonstrates. It bears repeated reading in order for the strength of his analysis fully to come across.

Its theme is not so much ‘which technology should we shift to?’ as ‘why can’t otherwise sensible people add up?’ The main construct of MacKay’s book is working out a plausible budget, as if on the back of an envelope, with the red column listing how much energy we consume and the green column listing how much we produce (or could produce using various low greenhouse gas-producing technologies). Can this budget possibly be balanced and how?

Through a number of relatively brief and insightful chapters, with anything too technical or mathematical relegated to appendices, the author gives us a few simple intellectual tools to figure out the answer for ourselves, with simple maths plus a useful human-scale framework for thinking sensibly about energy. As a good scientist, his tune is ‘numbers not adjectives,’ as he mercilessly cuts through the fog of empty propaganda words that has tends to surround energy debates.

A major advance of the book is in the explaining of the units of power and energy and trying to compare them on a consistent basis. This involves several heroic assumptions, but the end definitely justifies the means. The result is to dispel the hot air of most claimants for sustainable solutions as well as those who deny the need to take any action at all.

MacKay clearly has an admirable talent for making quantitative ideas easy to understand, and even satisfyingly fun to work out. He quickly debunks some of the more silly myths, such as that turning off mobile phone chargers will ever make a serious dent in energy use. ‘Every little helps’ is correctly seen as evading the real issue – in other words, that we need large-scale changes. After responding with a simple calculation to the objection that building a nuclear power plant would consume ‘huge’ amounts of concrete and steel and therefore cause ‘huge’ pollution, he simply notes, “Please don’t get me wrong: I’m not trying to be pro-nuclear. I’m just pro-arithmetic.”

Another strength of the book, and where it differs from many others, is that the author does not preach to the reader from a position of untouchable authority. Instead he invites the readers to analyse their own energy usage, providing them (if they are keen) with the tools to calculate the numbers that appear in the book from their own sources (gas and electricity bills, supermarket receipts, petrol station receipts, etc.). The author then takes the reader through many kinds of sustainable energy generation methods. The book includes easy-to-follow calculations of the impact that each method can make on our personal energy usage. Finally, a number of possible solutions are discussed.

“It would seem intuitively obvious that a lot of light could be thrown on discussions about energy matters by referring to agreed numbers. Yet this isn't as easy as it sounds - the energy business is notorious for a huge number of measuring units, and it is difficult to compare like with like.”

The book is not only about how your personal energy usage makes a difference, but is also a crystal-clear case study of the application of scientific methods to everyday problems. As such, it educates the reader not only about the issues of sustainability, but also about how ordinary people can apply scientific thinking in their lives.

Doing so only requires average school-leaver mathematics. In fact, there is no need to apologise about a simple bit of maths and science that puts some rational arguments behind the vast array of political and bandwagon ‘solutions’ to our environmental problems. The questions posed are many and varied. Wind energy might well work for the UK if we are prepared to devote huge amounts of land to it and there were feasible storage systems available. Growing crops for transport fuel is the least efficient way of using our limited land resources. Can air travel be made much more efficient, as proponents of the third Heathrow airport runway would have us believe?

Most of what we hear about energy science (and climate change) comes via the questionable filter of journalism. Journalists instinctively soften, harden or spin stories according to the needs of their publication and their career. After all, no journalist wants to write a heavily committed story only to find that it’s all disproved and they have been publicly duped. Also, journalists dislike being too definite about anything because it will alienate readers. Much better to uses phrases like ‘suggests that’ rather than ‘proves that’ if you are looking to enrage the fewest possible readers. Unfortunately, such approaches tend to dilute, and sometimes even emasculate, the original message.

Unfortunately for the interested but non-scientific reader, the results of most scientific work are published in forms that assume far too much foreknowledge to be accessible. This means that scientific knowledge is often only accessible to the man in the street in regurgitated form through the mainstream media, with all the problems outlined above. MacKay’s book essentially provides a solution to this. For those who want to investigate matters further and have a higher understanding of maths and science, many later chapters match the earlier ones with more detailed explanations. Even for those less well-versed, these chapters are worth persisting with as they are themselves very illuminating.

Climate-change sceptics should certainly read the book, not to be converted, but to understand that these challenges need to be faced even if our fossil fuel habits had no impact on climate. And renewable energy enthusiasts should read it to understand the practical limits of the various low-carbon options. Nuclear opponents should read it to realize the costs of avoiding the risks they reject.

The conclusion from reading it is that the IEA is right in its recent work – we need to diversify our options to include renewables, nuclear, possibly some carbon capture and storage, but also achieve huge efficiency improvements. But we don’t yet have the policies in place to make this happen, partly because most people are not very good at adding up.

One interesting aspect of MacKay’s work is that he admittedly ignores economic factors. This may initially be seen as a weakness, but it turns out to be a sensible decision; omitting economics removes one additional possible additional area of confusion. If critics fail to debunk the arguments in favour of any solution, their last line of defence is always to claim that ‘it will cost too much’. And the book is none the worse for this simplification, as MacKay can draw ready conclusions about the real, quantifiable and measurable potential of each energy source without getting bogged down in billions of pounds, Euros or dollars.

The analysis is initially couched very much in terms of what the UK could do to solve its energy problems, but it is then extended to the wider world, albeit with another set of assumptions. As ever his main recommendation is, “Make sure your policies include a plan that adds up”.

If there is a weakness, it lies in the inadequate treatment of the issues of intermittency and unreliability of renewables. Although demand management and storage are discussed, the treatment is not persuasive and one is left with the impression that the case for renewables supplying a high percentage of world energy is actually even weaker than stated. Nuclear clearly can avoid such issues but it is not endorsed with much enthusiasm by the author, who seems to have been influenced by advocacy of the many conceivable difficulties attached to major nuclear programmes.

To summarise, the book is sharp, accurate, quantitative and at the same time clear, entertaining and compelling. It is also well-illustrated with good photographs and informative diagrams and maps. It’s even available at no charge as a full-quality PDF download from the author’s own web site www-withouthotair-com, while there is a good interview-with-david-mackay-on-youtube. Although he clearly didn’t set out to make money from his book, David MacKay has become quite famous and has been appointed as an adviser at the UK Department of Energy and Climate Change. He will hopefully shake up as many things as possible while he is there.


Author Info:

Steve Kidd is director of strategy & research at the World Nuclear Association, where he has worked since 1995 (when it was the Uranium Institute). Any views expressed are not necessarily those of the World Nuclear Association and/or its members.

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