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Sustainable energy - without the hot air, by David JC MacKay (ISBN: 978-0954452933, web site)
In short: read this book. Now.
Every so often, when considering 'green' issues, I'll find myself pondering a question like 'compared to a car engine, how much CO2 does a person cycling give off?' or 'surely even inefficient light bulbs give off heat, which means that I have to heat the room less, so how do those savings compare?' When Top Gear broke the story about bio-fuels to the masses back in 2003, one of my first thoughts was: 'OK, that's great, but let's say we take every car currently running on diesel and power it from rapeseed oil instead, how much land are we going to need to grow the rapeseed, and will there be any space left to build roads on?'
Such questions aren't rhetorical. They're amenable to scientific analysis (I did actually make an attempt at looking up the rapeseed one from publicly available figures), and I always harboured a dream of sitting down and working out the figures. But now I don't need to, because David MacKay, a Professor of Physics at Cambridge, has done it for me. And much, much more.
His central simplification is to use a fixed unit throughout; he measures power in kWh/d, or kilowatt hours per day. If this seems odd to the physicists among us - he could just as easily have used a kW, 1kW = 24 kWh/d and doesn't have that awkward 'hours per day' bit - he justifies it by calling it a handy human-sized quantity. a 40W light bulb, for example, uses 1kWh/d when switched on, and allegedly it's also the sort of power you'd get from one human servant. Anyway, the important thing is to use consistent units throughout, which he does. This allows us to compare all the different ways that we use power with the different ways that we can generate it.
For example, someone driving 30 miles every day uses about 40kWh/d. If I fly in a fully-loaded plane to San Francisco and back once a year, I use 30kWh/d. Covering my roof with solar panels could deliver 13kWh/d of heating, or 5kWh/d of electricity (but not both). As the book goes on, he stacks up the per-person consumption of energy in a red bar alongside the per-person possible generation of energy from renewables in green.
I don't want to give away the ending, but basically unless we cover 5% of the UK with solar panels, 10% with wind farms (in the same places), enclose the North Sea in a tidal barrier and burn all our waste, we're buggered. Without reducing our energy consumption (back to the pre industrial era levels, and probably reduce our population to those levels as well), or start using non-renewable sources of energy, the sums simply don't add up.
The good news is that David MacKay has several suggestions for where to go from here. The bad news is that all of them have some aspect that most people won't like, whether it's relying on nuclear power, using 'clean coal' power stations, importing energy from other countries that can make better use of renewables or an expensive and resource-hungry programme of building wind turbines.
In a way, though, that's beside the point. If you have a better plan, this book will help you do the sums for it. This also helps to compensate for one of the other problems with the book, which is that it's very UK-centric - although this is just a narrowing of focus; he considers the global context where it's appropriate, and has a chapter where he does the same sums for the US, and for the rest of Europe.
It's also worth mentioning that this is very much a book about sustainable energy, not climate change or 'carbon footprint'. He does talk a little about both of those, but it's not the main thrust of the book, which is about securing an energy supply that's not going to run out in 100 years or so. Obviously, reducing or eliminating fossil fuels from the power-generating equation is a key component of that, so incidentally CO2 emissions will be reduced, but even if you think that the greenhouse effect is exaggerated, or just scaremongering, you should read this book. The unsustainablity of our fossil fuel use is very real indeed.
That said, not all of the options he offers here are completely sustainable, largely because it's very, very hard to make the figures add up at all when looking purely at sustainable solutions. So he also considers solutions that 'will last us for the next 1000 years', as being close enough to sustainable as to be worth considering.
In part 1 of the book, the chapters alternate between power consumption and power generation, building up an overall picture of the balance. Part 2 considers possible solutions - these vary a lot, but some common themes are: favour electric transport, especially trains; improve the insulation of all buildings, but especially new builds; heat and cool houses through heat pumps. David MacKay likes heat pumps a lot, if I were at all suspicious that his research is being funded by an interested party, it would be a firm that makes heat pumps.
Part 3 goes into the technical details of some of the topics in part 1: the physics of deep-water waves, why aeroplanes are already about as efficient as they're ever going to be. This is a masterstroke - it allows him to stick to the calculations in part 1 without getting too bogged-down in where the figures come from, while giving details of the science behind the figures so that interested science-minded people can check his working. Similarly, there's a section at the end of each chapter where he lists references and further reading. He's separated these out very well, and there's usually enough information in the main body of the text to let you know what he's talking about without it breaking up the flow of the argument. Part 4 gives detailed figures and web links.
Actually, it's worth mentioning that this book is a great read. It's witty, the diagrams and tables are clear, and he comes up with some great analogies, like illustrating the problem with generating sustainable geothermal power by talking about drinking slushies. The whole book is available for free on the web site - if you like reading things on-line, by all means do that, but I found the book itself easier to flick backwards and forwards through.
I really, really like this book. If there's any justice, this book will become as popular a scince read as A Brief History of Time or The Blind Watchmaker, although I think it's both more accessible and more immediately relevant to day-to-day life than both of those. I'm considering buying ten copies and sending them to key politicians talking about the subject. I'm considering refusing to engage with anyone on the subject of energy policy until they've either read the book or demonstrated to my satisfaction that they're clued up enough on the figures not to need to. I like this book enough that I'm very wary of the happy death spiral with respect to it, but I think I can avoid it. At heart, the book is a set of numbers that either add up or don't, from sources that can be checked. I intend to check as many as I can.
And then to buy a heat pump.
In short: read this book. Now.
Every so often, when considering 'green' issues, I'll find myself pondering a question like 'compared to a car engine, how much CO2 does a person cycling give off?' or 'surely even inefficient light bulbs give off heat, which means that I have to heat the room less, so how do those savings compare?' When Top Gear broke the story about bio-fuels to the masses back in 2003, one of my first thoughts was: 'OK, that's great, but let's say we take every car currently running on diesel and power it from rapeseed oil instead, how much land are we going to need to grow the rapeseed, and will there be any space left to build roads on?'
Such questions aren't rhetorical. They're amenable to scientific analysis (I did actually make an attempt at looking up the rapeseed one from publicly available figures), and I always harboured a dream of sitting down and working out the figures. But now I don't need to, because David MacKay, a Professor of Physics at Cambridge, has done it for me. And much, much more.
His central simplification is to use a fixed unit throughout; he measures power in kWh/d, or kilowatt hours per day. If this seems odd to the physicists among us - he could just as easily have used a kW, 1kW = 24 kWh/d and doesn't have that awkward 'hours per day' bit - he justifies it by calling it a handy human-sized quantity. a 40W light bulb, for example, uses 1kWh/d when switched on, and allegedly it's also the sort of power you'd get from one human servant. Anyway, the important thing is to use consistent units throughout, which he does. This allows us to compare all the different ways that we use power with the different ways that we can generate it.
For example, someone driving 30 miles every day uses about 40kWh/d. If I fly in a fully-loaded plane to San Francisco and back once a year, I use 30kWh/d. Covering my roof with solar panels could deliver 13kWh/d of heating, or 5kWh/d of electricity (but not both). As the book goes on, he stacks up the per-person consumption of energy in a red bar alongside the per-person possible generation of energy from renewables in green.
I don't want to give away the ending, but basically unless we cover 5% of the UK with solar panels, 10% with wind farms (in the same places), enclose the North Sea in a tidal barrier and burn all our waste, we're buggered. Without reducing our energy consumption (back to the pre industrial era levels, and probably reduce our population to those levels as well), or start using non-renewable sources of energy, the sums simply don't add up.
The good news is that David MacKay has several suggestions for where to go from here. The bad news is that all of them have some aspect that most people won't like, whether it's relying on nuclear power, using 'clean coal' power stations, importing energy from other countries that can make better use of renewables or an expensive and resource-hungry programme of building wind turbines.
In a way, though, that's beside the point. If you have a better plan, this book will help you do the sums for it. This also helps to compensate for one of the other problems with the book, which is that it's very UK-centric - although this is just a narrowing of focus; he considers the global context where it's appropriate, and has a chapter where he does the same sums for the US, and for the rest of Europe.
It's also worth mentioning that this is very much a book about sustainable energy, not climate change or 'carbon footprint'. He does talk a little about both of those, but it's not the main thrust of the book, which is about securing an energy supply that's not going to run out in 100 years or so. Obviously, reducing or eliminating fossil fuels from the power-generating equation is a key component of that, so incidentally CO2 emissions will be reduced, but even if you think that the greenhouse effect is exaggerated, or just scaremongering, you should read this book. The unsustainablity of our fossil fuel use is very real indeed.
That said, not all of the options he offers here are completely sustainable, largely because it's very, very hard to make the figures add up at all when looking purely at sustainable solutions. So he also considers solutions that 'will last us for the next 1000 years', as being close enough to sustainable as to be worth considering.
In part 1 of the book, the chapters alternate between power consumption and power generation, building up an overall picture of the balance. Part 2 considers possible solutions - these vary a lot, but some common themes are: favour electric transport, especially trains; improve the insulation of all buildings, but especially new builds; heat and cool houses through heat pumps. David MacKay likes heat pumps a lot, if I were at all suspicious that his research is being funded by an interested party, it would be a firm that makes heat pumps.
Part 3 goes into the technical details of some of the topics in part 1: the physics of deep-water waves, why aeroplanes are already about as efficient as they're ever going to be. This is a masterstroke - it allows him to stick to the calculations in part 1 without getting too bogged-down in where the figures come from, while giving details of the science behind the figures so that interested science-minded people can check his working. Similarly, there's a section at the end of each chapter where he lists references and further reading. He's separated these out very well, and there's usually enough information in the main body of the text to let you know what he's talking about without it breaking up the flow of the argument. Part 4 gives detailed figures and web links.
Actually, it's worth mentioning that this book is a great read. It's witty, the diagrams and tables are clear, and he comes up with some great analogies, like illustrating the problem with generating sustainable geothermal power by talking about drinking slushies. The whole book is available for free on the web site - if you like reading things on-line, by all means do that, but I found the book itself easier to flick backwards and forwards through.
I really, really like this book. If there's any justice, this book will become as popular a scince read as A Brief History of Time or The Blind Watchmaker, although I think it's both more accessible and more immediately relevant to day-to-day life than both of those. I'm considering buying ten copies and sending them to key politicians talking about the subject. I'm considering refusing to engage with anyone on the subject of energy policy until they've either read the book or demonstrated to my satisfaction that they're clued up enough on the figures not to need to. I like this book enough that I'm very wary of the happy death spiral with respect to it, but I think I can avoid it. At heart, the book is a set of numbers that either add up or don't, from sources that can be checked. I intend to check as many as I can.
And then to buy a heat pump.
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The environmental equations I have trouble with tend to be the ones that don't lend themselves to being measured in a single unit. Is it better to use cloth kitchen towels (which use cotton fibers, require heat and water and soap to be expended in washing, and can transmit food-borne illnesses) or paper towels (which use trees, are processed with chemicals, and go into landfills)? That's not just about energy; it's about waste management and resource usage and health. I haven't yet heard of anyone figuring out a good general way to address the more complex situations that day-to-day environmentalists face.
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Re: Review: Sustainable energy - without the hot air, by David JC MacKay