I suspect that this book review may qualify as the longest ever in the Guinness Book of Records. I make no apologies for this because this book contains as many authoritative, concentrated facts as others which are five times longer. However, if you want to summarise this book into one sentence, I cannot do better than plagiarise Matthew Moss' review of it, "I took it into the loo and almost didn't come out again."! This kind of criticism may be common for the latest thriller, but for a technical book on energy and the environment, it must be unique - and deservedly so. David MacKay has a fantastic ability to captivate his readers, whether they be beginners or experts, with a mix of easy-to-understand fact, humour and readability. This is largely because he does not try to blind the reader with abstruse science when a simpler expression will do. I'll quote him to try to illustrate some of the points I'd like to make:
Perhaps the worst offenders in the kingdom of codswallop are the people who should know better - the media publishers who promote the codswallop - for example, New Scientist with their article about the "water-powered car."
In a climate where people don't understand the numbers, newspapers, campaigners and politicians can get away with murder...
The book, a good kilogram (not bad for a paperback!) of sturdy fact and opinion, is divided into four parts plus a host of other useful references, links and that rare bird, a good index. Each part is divided into a number of chapters, 43 in all. The title of the first part, 'Numbers, not adjectives' may sound off-putting to the layman, but none of it; the quotation above is from the initial chapter, one of the longest, 'Motivations'. I'll translate the theme into my own words: why the heck am I reading yet one more book on the eternal subjects of energy conservation and climate change? The answer is simple: it is without the male bovine excrement common to works written by vested interests; it is easy to understand and richly illustrated. For example, a graph shows how the EDF projects electricity production capacity from 'conventional' sources will evolve in the UK (the book is rather Brit-oriented, but the situation is similar elsewhere), because of power plant closures.
Congratulations, Britain! The UK has made it to the winners' podium. We may be only an average European country today, but in the table of historical [CO2] emitters, per capita, we are second only to the USA.
The second chapter discusses the balance between all forms of energy consumption and sustainable production. It includes the important concept of differentiating between power and energy, a trap that many fall into. The author explains why he has chosen to use the kWh for his unit of energy throughout the book, no matter whether the energy is used in an electric kettle, a car or burning wood in a fireplace, and kWh/day as his unit of power, with his now-famous 40 W light bulb consuming 1 kWh/day, simply because ordinary people, like myself, can better visualise what this means.
For the next chapters, there is an alternation between consumption and production: cars, wind, planes, solar, heating and cooling, hydroelectricity, light, offshore wind, gadgets, wave, food and farming, tide, stuff, geothermal, public services and part 1 winds up with the question, 'Can we live on renewables?' Colours (red for consumption, green for production) for these chapter titles are used throughout the book! Space does not permit me to give a detailed review of each chapter in the first part, so I'll restrict myself to a few sound-bites or, rather, keyboard-bites:
What about the energy-cost of producing the car's fuel?
The maximum plausible production from on-shore windmills in the United Kingdom is 20 kWh per day per person [consumption of a car is 40 kWh/d] ... wind farm (speed 6 m/s) 2 W/m2 [of land] ... 4000 m²/person
Flying once per year [from London to Cape Town or Los Angeles] has an energy cost slightly bigger than leaving a 1 kW electric fire on, non-stop, 24 hours a day, all year.
Typical solar [photovoltaic] panels have an efficiency of about 10%; expensive ones perform at 20%... The average power delivered by south-facing 20%-efficient photovoltaic panels in Britain would be ... 22 W/m²
Fantasy time: solar farming
...Well, if we covered 5% of the UK with 10%-efficient panels, we'd have ... 50 kWh/day/person ... the solar power capacity required to deliver this 50 kWh per day per person in the UK is more than 100 times all the photovoltaics in the whole world.
The biggest use of hot water in a house might be baths, showers, dish-washing or clothes-washing - it depends on your lifestyle. ... So the energy required to heat up the water [for a bath] is ... about 5 kWh.
The actual power from hydroelectricity in the UK today is 0.2 kWh/d per person, so this [practical limit of] 1.5 kWh/d per person would require a seven-fold increase in hydroelectric power.
In some countries, drivers must switch their lights on whenever their car is moving, How does that extra power required by that policy compare with the power already being used to trundle the car around? ... So having the lights on while driving requires 2% extra power.
The outcome: if an area equal to a 9 km-wide strip all around the [UK] coast were filled with turbines, deep offshore wind could deliver a power of 32 kWh /d per person. A huge amount of power, yes; but still no match for our huge consumption. And we haven't spoken about the issue of wind's intermittency.
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 1% (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.
First, let's clarify where waves come from: sun makes wind and wind makes waves ... Let's assume that brilliant wave-machines are 50%-efficient at turning the incoming wave power into electricity, and that we are able to pack wave-machines along 500 km of Atlantic-facing coastline.... That's 4 kWh per day per person. As usual, I'm intentionally making extreme assumptions to boost the green stack - I expect the assumption that we could line half of the Atlantic coastline with wave absorbers will sound bananas to many readers.
The embodied energy in Europe's fertilisers is about 2 kWh per day per person. According to a report to DEFRA by the University of Warwick, farming in the UK in 2005 used an energy of 0.9 kWh per day per person for farm vehicles, machinery, heating (especially greenhouses), lighting and ventilation and refrigeration.
The engineers' reports on the proposed Severn barrage say that ... it would contribute 0.8 kWh/d per person on average.
Let's assume you have a Coke habit: you drink five cans of multinational chemicals per day, and throw the aluminium cans away. For this stuff, it's the raw material phase that dominates. The production of metals is energy intensive, especially for aluminium. Making one aluminium drinks-can needs 0.6 kWh. So a five-a-day habit wastes energy at a rate of 3 kWh/d. As for a 500 ml water bottle made of PET (which weighs 25 g), the embodied energy is 0.7 kWh - just as bad as an aluminium can!
But sadly for Britain, geothermal will only ever play a tiny part.
Sometimes people ask me "surely we used to live on renewables just fine, before the Industrial Revolution?" Yes, but don't forget that two things were different then: lifestyles, and population densities.
Turning the clock back more than 400 years, Europe lived almost entirely on sustainable sources: mainly wood and crops, augmented by a little wind power, tidal power, and water power. It's been estimated that the average person's lifestyle consumed the power of 20 kWh per day. The wood used per person was 4 kg per day which required 1 ha (10,000 m²) of forest per person. The area of land per person in Europe in the 1700s was 52,000 m². In the regions with the highest population density, the area per person was 17,500 m² of arable land, pastures and woods. Today the area of Britain per person is just 4000 m², so even if we reverted to the lifestyle of the Middle Ages and completely forested the country, we could no longer live sustainably here. Our population density is far too high.
So, what does the second part of the book say? It bears the title, "Making a difference". The first chapter, "every BIG helps", tells us, very clearly, that we have little choice that, to get off fossil fuels, it requires both reductions in demand and increases in supply, both of which must be big. To reduce the demand would require reducing our population, changing our lifestyle and reducing our lifestyle's energy intensity through better efficiency and more technology. To increase the supply beyond the little we can obtain from renewable sources, we could use nuclear fission, possibly "clean coal" technology or we could "buy, beg, or steal renewable energy from other countries.". The first of these has, of course, emotive issues, the second is still experimental and must be costly and the third must be surrounded by a very large question mark.
Obviously, transport is something that we can improve either with more efficient vehicles or increased use of public transport. Some Japanese data provide us with the energy consumption in kilowatt-hours per hundred passenger-kilometres: car 68, bus 19, rail 6, air 51, sea 57. One of the many charts shows that the carbon dioxide emissions from some popular cars on the market vary from 99 to 420 g per kilometre. One omission from this book is the way that car manufacturers cite their consumption and emissions. A recent television programme that I watched showed how these figures were able to be manipulated to be as favourable as possible, so that the ordinary user could not possibly duplicate the numbers! This leads us to some sections on hybrid cars and electric vehicles, giving some data on what is available on the market. He gives full marks to the electric vehicle (personally, I'm not so convinced), assuming the principle that the energy is generated from a non-fossil fuel source, which is unlikely in most countries, except France. He then discusses compressed-air cars, which are energetically inefficient and hydrogen cars, which idea he believes is a "hyped-up bandwagon" (I agree with him wholeheartedly!). The author's favourite suggestion is to use the common or garden bicycle where this is feasible; where I live, it would be a sure way of committing suicide! In Britain, the author offers two photographs of cycle tracks which have been obstructed by steel barriers and lampposts!
The chapter on smarter heating is quite interesting and covers many aspects from insulation, using the thermostat, better building the use of combined heat and power and that great invention, the heat pump:
Let me spell this out. Heat pumps are superior in efficiency to condensing boilers, even if the heat pumps are powered by electricity from a power station burning natural gas.How can you use electricity efficiently? The International Energy Agency states that roughly 8% of residential electricity demand is consumed by equipment that is not even being used. Prof MacKay blames the equipment manufacturers for much of this because they penny-pinch rather than seek efficiency. He found that by regular meter-reading, he could trace the "electricity-sucking vampires" and make substantial reductions in his electricity consumption.
His next question is whether fossil fuels can be sustainable. In the sense that they are all extracted from the ground and are therefore limited in quantity, the answer must be a resounding no. However, he begs the question a little by suggesting that if known reserves and assumed consumption offer more than 1000 years of operation, then this could be classed as sustainable. If known reserves of coal were to be divided amongst the population of the world to generate electricity, this would provide only about 1.6 kWh of electricity per day per person, over that time period. In practice, it would be even less than this tiny amount because the world would want no carbon dioxide emissions and "cleaning" flue gases would take up a large slice of the generated power. "Clean coal is only a stop-gap." This brings us neatly into the next chapter and whether the uranium fuel for nuclear power is sustainable. The answer is positive but it requires the use of fast breeder technology and extraction of uranium from the oceans. Adding on thorium reactors increases the sustainability of nuclear-power. This form of generation has the advantage of very small land footprints. The big questions revolve around safety and storing spent fuel. The book was written before Fukushima and the author has concentrated more on the scandal of the Sellafield leaks than, say, Chernobyl. In reality, nuclear-power kills fewer people than any other method of generating electricity, with wind coming second. As for waste:
Whereas the ash from 10 coal-fired power stations would have a mass of four million tonnes per year (having a volume of roughly 40 litres per person per year), the nuclear waste from Britain's 10 nuclear-power stations has a volume of just 0.84 litres per person per year - think of that as a bottle of wine per person per year.
Most of this waste is low-level waste. 7% is intermediate level waste, and just 3% of it - 25 ml per year - is high-level waste.
The high-level waste is the really nasty stuff.... After 40 years, the level of radioactivity has dropped 1000-fold... after 1000 years, the radioactivity of the high-level waste is about the same as that of uranium ore.
Can we live on renewable sources from other countries? Because of the amount of land required to generate electricity, renewable facilities have to be country-sized to be effective. Essentially, this boils down to using concentrating solar power in deserts, up to 15 W/m². This is potentially feasible in the Sahara and Arabian deserts. It is equally feasible to have high-voltage DC power lines to transmit the power throughout Europe and the Middle East, albeit with losses. Nevertheless, the implementation will take decades and I don't think anybody knows how much it will cost!
Of course, most forms of renewable power fluctuate. For this reason, it is usual to have some form of backup from other sources to prevent interruption of supplies. Prof MacKay brings out the distinction between lulls (which may last for days) and slews where the power output might change in a matter of minutes. Pumped hydroelectric storage is the only way we have for storing large amounts of energy but few countries have the topography which renders it feasible, at least on a reasonable scale. He also offers an idea which sounds far-fetched but may just help, provided that electric cars become mainstream; this is to use their batteries in conjunction with smart chargers to cover fluctuations.
On the presumption that we shall require a given quantity of energy each day, five different scenarios are offered with different combinations of solar in deserts, clean coal, nuclear, tide, wave, hydroelectric, waste to energy, pumped heat, wood biomass, solar hot water, biofuels, photovoltaic and wind. These scenarios are easily adapted for the requirements and potential sources of any country. The only proviso is that the stack from each combination is the same size as the stack from the consumption in the same area.
On the whole, this book does not enter into much detail regarding the economics of moving into sustainable energy. Notwithstanding, there is a chapter which gives a rough costing of a scenario for the UK, showing the area of land required, the capacity in gigawatts, the total cost of implementation and the per person cost and the average power delivered. Again, these are flexible according to the availability of resources; for example, tidal lagoons are hardly feasible in landlocked countries like Switzerland or Austria! He compares the apparently astronomical costs with those of other projects such as widening motorways, the London Olympics, refurbishing the Ministry of Defence offices, space projects, corporate profits, the expenditure on arms and war, the bailout of banks and so on.
So what can be done now? We are not on track to a zero carbon future and this should be one of our top priorities to ensure a continuity of energy supply. This can be taken down to individual actions such as "put on a woolly jumper and turn down your heating thermostat."
There is an interesting chart showing the power consumption of different countries per capita against the GDP per capita in purchasing-power-parity US dollars, in the chapter of energy plans for Europe, America and the world. Recalculating the scenarios for Europe, if the aim is to get off all fossil fuels, Europe needs nuclear-power or solar power in other people's deserts or both. North America has enough potential of expansion of solar power in its own deserts, nuclear-power or both. The bottom line for the world is that the non-solar renewables may be huge but are not huge enough so, again, it is necessary to rely on more forms of solar power or use nuclear-power or both.
Is it possible to remove carbon dioxide from the atmosphere? This leads to four other questions: "is climate change happening?", "Is it caused by humans?", "Does it matter?" and "What should we do about it?". Reading this chapter leaves one in little doubt that doing so may not be very practical and certainly would be very expensive, at least on a scale that would make any difference to climate change.
The 32nd chapter is the shortest, less than half a page, but it is nonetheless very important and can be summed up in the single paragraph, "We need to stop saying no and start saying yes. We need to stop the Punch and Judy show and get building."
I'll dismiss part three of the book into one single paragraph, even though it is very important. It is entitled "Technical chapters" and there are eight of them. They detail the physics and mathematics of the subjects of eight of the red and green chapter headings in the sixth paragraph above. Each chapter is looked at analytically, usually far beyond what the average person would think about. For example, one of the shorter chapters is that on wave power. Superficially, we may think that harnessing waves is simply putting a device into the water in such a way that it mechanically converts the movement of the wave into electricity. More analytically, we have to look at the wave speed produced by a given wind speed, the periodicity of the wave, the wavelength and the power, as well as the means to do the conversion. These variables are simplified graphically, but also with the formulas for each one. Then there is the difference between deep water and shallow water waves. Similar analyses are done for all the other chapters in this part of the book.
The fourth and last part of the book is simply entitled "Useful data". The first chapter is a quick reference, starting with SI units and other ones, some of which the author has made up himself. This is followed by "a whole bunch of commonly used units that are annoying for various reasons". The author lists them to allow the reader to understand (perhaps) what he reads in the media! He then goes on to a list of funny units which include the fact that 9,000,000 cups of tea per year is another way of saying 20 kW and that one Wembley is 44,000 double-decker buses! The following chapter is on populations and areas and the next one after that is on the history of UK energy. This is completed with web links and a good bibliography.
As I trust I have made it very clear, this book is oriented on the situation in Britain. This does not mean that it should be read only by Brits. As it happens, I live in Cyprus. As I have gone through the book to write this review I have mentally converted the data and the hypotheses to the Cypriot situation, without any difficulty. About the only thing in common between Britain and Cyprus is that they are both islands. One has a population of 60 million and the other has a population of 800,000. One is a place which experiences strong winds and the other is a place with a relatively weak ones. One has strong ocean tides and the other has practically none. One has comparatively little sunlight and the other has much. One has reasonable public transport, the other doesn't. One has an area of 244,000 km², the other 9,241 km². No, I was wrong! They have one other thing in common: very poor energy and environmental policies, although the UK is ahead of Cyprus in a number of important ways.
In my view, it doesn't matter two hoots where you live; this book is relevant to where you are and who you are. I do not hesitate in recommending it to anyone with just, at the least, the very slightest interest in the world around him or her. It doesn't cost you a penny to download it from the Internet, especially if you don't mind reading it off the screen. I bought the cheaper hard copy version because printing it out would have cost more than purchasing it (my Scottish blood comes to the fore!). Finally, I emphasise that Prof MacKay has written it to be eminently readable and he has a great sense of humour, as well as being right with his reasoned arguments (at least, for 98% of the time, in my opinion!).
Enjoy it!show more