University of Cambridge

In the accessible Sustainable Energy - without the hot air, scientist Professor David MacKay from Cambridge University offers detailed recipes to free Britain of its carbon habit.

His unique book emphasizes two technologies for making Britain more energy efficient: Britain must replace all its petrol and diesel cars by electric transport; and all building-heating systems must be replaced by heat pumps. (Heat pumps work like back-to-front refrigerators, using a little electricity to move a lot of heat into the building from the air or ground outside the building.)

Sustainable Energy - without the hot air describes the scale of effort necessary to provide all Britain's energy from zero-carbon sources and lays out the numbers required for constructive energy discussions. For renewables to make a significant contribution, country-sized renewable facilities are required, either in our country or in someone else's. The other options that could contribute to the zero-carbon energy mix are not unproblematic either - nuclear power, and coal with carbon-capture and storage. Professor MacKay emphasises that "it's not going to be easy to make an energy plan that adds up but it is possible".

During the course of his book, MacKay tackles the following questions in a factual, objective and readable manner. How much energy do we use, per person? How much energy could we produce from renewables, per person? How big will renewable facilities need to be, in order for renewables to make a sizeable contribution? What are our other sustainable energy options, apart from renewables, and how much could they produce? How easy is it to get off our fossil fuel habit? Could Britain live on its own renewables? How does our current energy consumption compare with our sustainable energy options?

MacKay also explores current consumption of energy, what could conceivably be generated by renewables in a country like Britain, and the potential of efficiency measures and new technologies to reduce consumption.

In the following excerpt, MacKay grapples with the debate of wind versus nuclear. As he states in his book, "Greater polarization of views among smart people is hard to imagine."

This heated debate is fundamentally about numbers. How much energy could each source deliver, at what economic and social cost, and with what risks? But actual numbers are rarely mentioned. In public debates, people just say "Nuclear is a money pit" or "We have a huge amount of wave and wind." The trouble with this sort of language is that it's not sufficient to know that something is huge: we need to know how the one "huge" compares with another "huge," namely our huge energy consumption. To make this comparison, we need numbers, not adjectives.

Where numbers are used, their meaning is often obfuscated by enormousness. Numbers are chosen to impress, to score points in arguments, rather than to inform."Los Angeles residents drive 142 million miles - the distance from Earth to Mars every single day." "Each year, 27 million acres of tropical rainforest are destroyed." "14 billion pounds of trash are dumped into the sea every year." "British people throw away 2.6 billion slices of bread per year." "The waste paper buried each year in the UK could fill 103,448 double-decker buses."

If all the ineffective ideas for solving the energy crisis were laid end to end, they would reach to the moon and back. . . . I digress.

The result of this lack of meaningful numbers and facts? We are inundated with a flood of crazy innumerate codswallop. The BBC doles out advice on how we can do our bit to save the planet - for example "switch off your mobile phone charger when it's not in use;" if anyone objects that mobile phone chargers are not actually our number one form of energy consumption, the mantra "every little helps" is wheeled out. Every little helps? A more realistic mantra is: if everyone does a little, we'll achieve only a little.

MacKay also delves into the common misconceptions about energy use. For example, in the chapter 'Gadgets' he highlights one of society's most Lilliputian energy-saving initiatives.

Modern phone chargers, when left plugged in with no phone attached, use about half a watt. In our preferred units, this is a power consumption of about 0.01 kWh per day. For anyone whose consumption stack is over 100 kWh per day, the BBC's advice, always unplug the phone charger, could potentially reduce their energy consumption by one hundredth of one percent (if only they would do it).

Every little helps! I don't think so.

Obsessively switching off the phone-charger is like bailing the Titanic with a teaspoon. Do switch it off, but please be aware how tiny a gesture it is. Let me put it this way: All the energy saved in switching off your charger for one day is used up in one second of car-driving. The energy saved in switching off the charger for one year is equal to the energy in a single hot bath.

In an effort to raise awareness of the energy problems (and solutions) facing the UK, MacKay has made his book available free online.

Endorsements:

The energy book has cross-party support. Industry leaders, scientists, environmentalists, and politicians of all colours have praised David MacKay's new book for its clear and objective presentation of energy arithmetic.

Tony Juniper, former Executive Director of Friends of the Earth, said: "For anyone with influence on energy policy, whether in government, business or a campaign group, this book should be compulsory reading."

Robert Sansom, Director of Strategy and Sustainable Development, EDF Energy, said: "At last a book that comprehensively reveals the true facts about sustainable energy in a form that is both highly readable and entertaining."

Michael Meacher MP, Former Environment Minister, said: "This hugely important book . . . should be a 'must read' not only at home and in industry, but on each Government Minister's desk, and not just in the UK."

Peter Ainsworth MP, Shadow Secretary of State for Environment, Food, and Rural Affairs, said Sustainable Energy -without the hot air, is "engagingly written, packed with useful information, and refreshingly factual."

Prof Martin Rees FRS, President of the Royal Society, said: "Energy policy is crucial for the world, and a wide public should be engaged in debate and decisions on these issues. But such debate must be grounded in realistic numbers and good physics. All the key principles are clearly and accessibly explained in this book. David MacKay has performed a great service by writing it."

Sir David King FRS, Chief Scientific Adviser to the UK Government, 2008, said: "This remarkable book sets out, with enormous clarity and objectivity, the various alternative low-carbon pathways that are open to us."

For more information about the book or to download it for free, please click here

Reproduced courtesy University of Cambridge Office of Communication