Posts Tagged ‘Sustainable energy’

Sustainable energy, without the hot air

Tuesday, March 30th, 2010

Sustainable Energy – without the hot air” is a book by David MacKay. It’s a thorough but clear analysis of how Britain could attempt to satisfy its present power-requirements without trashing the climate.

The book is available on the web for free download as a PDF and in other formats. David is more interested in having the book read than in making a profit from it. If you’d like to have a taste before reading the whole book, you can start with the 10-page summary he also provides on his site.

I think this is one of the most important books on tackling climate change that I have come across. Anyone who wishes to understand the complex question of how to reduce the carbon footprint of a nation should definitely read it. There are several reasons why I think that, here are some of them.

David MacKay

David MacKay

Though David is a every inch a scientist, the book is written in plain english, you don’t need a PhD to understand it. That said, non-native English speakers may have to look up words like ‘twaddle’ in a dictionary from time to time.

David starts by considering how much energy the British need to run their daily lives. By converting all uses of energy to a single unit he can produce a simple yet useful picture that includes electricity, transport, heating, food, and other lifestyle factors. This makes it easy to see what part of our lives is responsible for consuming energy, which makes it easy to see where we should look if we want to make changes.

He does not promote or favour a particular technology as part of the solution. He is not pro-wind, pro-solar, pro-nuclear, or pro-clean-coal. Nor is he against any of these or other climate-friendly energy-generation technologies. He considers all possible contributions to lowering Britain’s carbon footprint. Then he goes on to see if any different mix of technologies can possibly meet Britain’s energy requirements, or if it simply doesn’t add up. This makes the whole book very easy to comprehend.

He keeps things simple by looking only at what could potentially be done, if we captured all the available sources of energy. So, he looks at the total amount of wave-power energy arriving along the entire Atlantic coast. He looks at the total solar power we could get if we put panels on every south-facing rooftop. He considers the power we could get from wind if we put up turbines everywhere we feasibly could. He clearly and concisely works out what we could hope to get if we deploy these and other technologies on a nation-wide scale.

He is fully transparent about everything he does. All his assumptions are explained, he tells us where all his numbers come from, and he gives references to the material he used. So you can check his numbers yourself, there is no need to decide if you trust him or not. It’s all there for you to verify. He also uses round numbers, rather than quoting calculations to 10 decimal places like Spock in Star Trek, so we can follow the big picture more easily.

He does not rule out anything for political reasons, or for ethical reasons. He concentrates strictly on the basic facts instead. As he says:

This book is emphatically intended to be about facts, not ethics. I want the facts to be clear, so that people can have a meaningful debate about ethical decisions.

and

I don’t want to feed you my own conclusions. Convictions are stronger if they are self-generated, rather than taught. Understanding is a creative process. When you’ve read this book I hope you’ll have reinforced the confidence that you can figure anything out.

These days, there is so much written about climate change and what we need to do about it, with so many people reaching different conclusions, that is can be very hard to know who to trust. Some authors have their own conclusions that they want to convince us to agree with, so they bias their writing. Some fail to take account of important factors, which makes their conclusions unreliable. Some are deliberately trying to mislead us, working to a hidden agenda, as happens in so many walks of life. Some, finally, are simply too difficult to understand, with complex arguments that non-experts have no hope of following. We live in a world where the opinion of an expert is considered suspect, and is often rejected because, being an expert, we believe that they must be biased.

The result is that we are left with a choice among different viewpoints without knowing the facts, without knowing who is right or wrong, who is honest and who is not, or who is trying to manipulate us for their own gain. That’s not a good position to be in. That’s why it’s refreshing to find a scientist who wants us to reach our own conclusions.

That, in a nutshell, is why this book is important. Rather than pushing an agenda, David wants us to understand the limits of what we can do, and must do. He looks at the possibilities to see how they adds up, and he wants us to understand how he does it.

energy use per Briton per day (left) and energy available in renewables (right)

energy use per Briton per day (left) and energy available in renewables (right)

David’s simple way of looking at how we use energy is to convert everything to kilowatt-hours (kWh). One kWh is the amount of energy used by a 1 kW appliance left running for one hour. A 100 watt lightbulb running for 10 hours also uses 1 kWh. A 40 watt bulb would take 25 hours to use one kWh, and so on. Your electricity meter measures consumption in kWh, so it’s a sensible unit, we can all relate to it because it appears on our monthly bills.

Other forms of energy can also be expressed in kWh. Driving the mythical average car 30 miles (50 km) consumes about 40 kWh of energy in the form of petrol. So if your commute to work is a 30-mile round trip, 5 days a week, that uses about the same amount of energy as running a 1 kW heater all day long, every day. The heater would use 1 kW x 168 hours per week = 168 kWh per week, the car would use 40 kWh per day x 5 days, which equals 200 kWh. That’s close enough to being the same thing, as I’m sure David would agree.

Similarly, if you take one long-distance flight per year, that also works out to be the equivalent of 30 kWh per day for that year. So just getting to your holiday destination uses the same amount of energy as if you left a 1 kW heater on all day long, every day, for the whole year.

That’s not to say that these things are exactly equal. After all, if you do leave your heater on for a year, you won’t suddenly wake up in the Bahamas on New Year’s Day (more’s the pity!). But it does allow you to start comparing things. 1 long-distance-flight = commuting 30 miles per day to work for a year = a 1 kW heater left on all year long. So, if you want to reduce your carbon footprint, you might consider car-pooling with a colleague, which will halve your energy consumption for your commute. Or, if you could cut out that long-distance flight, that’s going to be twice as effective, equivalent to taking your car off the road completely!

David does all the other sums for us too. Heating accounts for 37 kWh per person per day. Lighting accounts for 4 kWh, electrical and electronic gadgets (such as computers, phones, stereos and vacuum cleaners) consume about 5 kWh. The food we eat requires about 15 kWh to produce, when you add up everything that goes into it. Consumer goods (from cars to newspapers and other things that we buy) come with a cost of about 49 kWh. That huge number comes up when you take account of the energy needed to produce the raw materials, manufacture the object, use it, and dispose of it. Packaging alone adds 4 kWh per day to our consumption.

So do you unplug your phone-charger, as we are often told to do? Sure, go ahead, though it won’t make much difference. Change your light bulbs and turn down your thermostat? Definitely some savings to be had there. Trade in that SUV for a real car? Great idea! Don’t overlook how much you can save in other ways, like not buying stuff you don’t need, and not throwing things out when there’s still some use in them. Small economies and reducing waste are always a good idea, but we need to make bigger changes, on a national scale, if we want to save the planet.

David also tackles the question of how to look at the energy needs of the entire country. This is where many analyses come unstuck. For example, take the recently announced wave and tidal energy projects in Scotland. These are described with phrases like “major milestone”, and “Saudi Arabia of marine power”. These projects between them will yield the same amount of electricity as a large nuclear power station. That sounds impressive, but is it really? Could we simply build more of these and satisfy our energy needs that way?

David MacKay points out that Britain has about 1000 km of Atlantic coastline, and the waves crossing it have an energy of 40 kW per metre of coastline. If we build wave-machines that can collect half of that, and build enough to cover half of our coastline, we would get (drum roll please) 4 kWh per person, per day. [update: See also "Tidal power - no thanks" in New Scientist]

That’s not so much after all, just enough to keep the lights on. Is it worth covering half the coastline with wave machines for that? It certainly doesn’t sound like Saudi Arabia to me!

Using a similar approach, David calculates that if we were to cover one tenth of Britain with windmills, that would give us each 20 kWh per day, or one sixth of what we currently use. Covering every south-facing roof with solar water-heating panels would give us 13 kWh per day. Biofuels? If we converted all the farmland in Britain to producing biofuels, that would give at most 36 kWh each per day (and no more food!).

David MacKays five plans for powering Britain

David MacKays five plans for powering Britain

David then goes on to consider what mix of technologies might be used to balance the energy needs of the UK in some foreseeable future, and proposes a number of simple plans to illustrate the possibilities and the limits of what might be achievable. Rather than go into details about them here, I’ll let you read the book for yourself and see if any of them appeal to you.

If you have the slightest interest in sustainable energy, I urge you to read this book. It’s the best illustration I’ve seen of what it means to wean a nation off of fossil fuels. That’s something that is really difficult to grasp, it’s such an enormous undertaking, yet David presents it in a way that makes sense. If you don’t want to let yourself be fooled by people with their own bias or hidden agenda, this is the book you need.

Copenhagen – now what?

Sunday, January 10th, 2010

The Copenhagen meeting finished some time ago now, and didn’t succeed in delivering anything useful. I’ve resisted the temptation to write about it earlier, rather I wanted to see what others said first, before making up my own mind about it. There’s been an awful lot of analysis published in the blogosphere since the meeting ended, I’m sure I’ve not encountered every view, but here are my own conclusions.

One thing is obvious, we did not get the fair, ambitious, and legally binding document we were all hoping for. Not even close. All we got was the ‘Copenhagen accord’, a piece of paper with no legal weight written by a few of the participants. That accord has no numbers in it that we can use to actually set policies. It does not state when emissions should peak, what reduction in emissions is required, in what timescale, or anything like that. There is no way to turn it into a plan of action, to decide how to tackle climate change based on what it says. It is worthless in itself, and is quite possibly worse than having no agreement at all.

By stepping outside the UN framework to produce that accord, those few countries that created it have seriously weakened the UNFCC process.
President Obama announced the accord to the press before most of the national representatives had even seen it, which shows a distinct lack of respect for protocol. How can the UNFCC be taken seriously now that a handful of leaders have ignored it and made up their own agreement?

On the other hand, it is not at all clear that anything else was on the table. I have not seen anything mentioned anywhere that the formal process of the UNFCC had created a document that was ready to be signed at the end of the meeting. If you know otherwise, please let me know via the comments. And, worthless as it is in practise, it is nonetheless significant that America and China have both signed even so weak a document as they did.

In the aftermath, the inevitable finger-pointing has taken place, with most people blaming someone half the world away for the failure. It’s difficult for an observer like myself to know what really happened, who is at fault, and why the process broke down. There was clearly a lot of good intention from many places, I doubt so many world leaders have ever been assembled in one place before. They wouldn’t all go there to look bad, I’m sure many of them wanted to come away with something real. Many countries went to Copenhagen having made pledges which, while inadequate, were much stronger than anything they have comitted to in the past. So what happened?

President Obama was clearly a key player, and he went there empty-handed. He didn’t offer anything new, much to the disappointment of many. The offer of ‘mobilising a fund of $100 billion annually for mitigation’ by 2020 is not worth much. Americans spend that much each year on bottled water, so it’s not exactly digging deep into their pockets. Besides, the International Energy Agency estimates that, for each year we delay action, the cost of tackling climate change will increase by $500 billion. So having $100 billion per year by 2020 really isn’t impressive.

It seems likely that, had America made a bigger comittment to cutting its own emissions, the conference could have gained a lot of momentum. With one of the highest levels of emissions per person in the entire world, America, like many western countires, has a clear debt to pay for the wealth it has accumulated. People were looking to President Obama to take the leading role he claimed he would when he was sworn into office. He failed to do that. To be fair, when you see the political pressure and tactics wielded by the fossil-fuel industries in America, it’s hardly surprising that President Obama couldn’t offer more. He simply doesn’t have that much power.

George Monbiot of the Guardian points out that Obama demanded concessions, despite offered nothing in return. On the other hand, Mark Lynas blames China for systematically blocking all attempts to name concrete targets. In Mark’s own words:

it was China’s representative who insisted that industrialised country targets, previously agreed as an 80% cut by 2050, be taken out of the deal. “Why can’t we even mention our own targets?” demanded a furious Angela Merkel. Australia’s prime minister, Kevin Rudd, was annoyed enough to bang his microphone. Brazil’s representative too pointed out the illogicality of China’s position. Why should rich countries not announce even this unilateral cut? The Chinese delegate said no, and I watched, aghast, as Merkel threw up her hands in despair and conceded the point. Now we know why – because China bet, correctly, that Obama would get the blame for the Copenhagen accord’s lack of ambition.

China, backed at times by India, then proceeded to take out all the numbers that mattered. A 2020 peaking year in global emissions, essential to restrain temperatures to 2C, was removed and replaced by woolly language suggesting that emissions should peak “as soon as possible”. The long-term target, of global 50% cuts by 2050, was also excised. No one else, perhaps with the exceptions of India and Saudi Arabia, wanted this to happen. I am certain that had the Chinese not been in the room, we would have left Copenhagen with a deal that had environmentalists popping champagne corks popping in every corner of the world.

You can read more on Mark’s views of Copenhagen at the New York Times dotEarth blog, it’s worth reading.

I think that both George and Mark make good arguments, as do many other writers, but I have to say I give a lot of weight to Mark’s analysis. Mark was in the room for the negotiations, he saw it all first-hand. I’ve read Mark’s book, Six Degrees, and was impressed at how well he took such a large body of research and summarised it in terms we can all understand. He’s also one of the few environmentalists who has come to understand the importance of nuclear power in addressing climate change. That’s why I trust him as an observer and a critical thinker, and take his opinion seriously.

So, given that the UN framework didn’t yield a result, and that those who wanted to do something were prevented from doing so by those that don’t, what does that mean for the future? Here, the blogosphere seems to be more in agreement, people-power still matters, and there are a lot of people who aren’t giving up.

People from all walks of life have been calling for action on climate change. George Monbiot, in that same article above, is quite blunt about blaming people for complacency.

For the past few years good, liberal, compassionate people – the kind who read the Guardian – have shaken their heads and tutted and wondered why someone doesn’t do something. Yet the number taking action has been pathetic.

I guess he’s right. I know I came late to the party, and wish I had acted sooner.

At the other end of the scale, a group of international investors managing $13 trillion in assets also called for strong action (full report (PDF)). You can bet that they wouldn’t be asking for strong legislation to attack global warming unless they thought that it was needed for the global economy to survive.

Young people are getting in on the act too. Take a look at the video below, produced by the Australian Youth Climate Coalition. Their message to world leaders is load and clear:

Those of you who say it can’t be done should get out of the way of people already doing it. Our future will not be written for us, but by us. You’re not done yet. And neither are we.

It’s great to know so many people from such different levels of society want action, but it won’t be enough to simply tell governments to act. It’s important that people both understand what is needed and agree on how to act, so a clear, unified, and sensible message is sent to political leaders. One of the biggest problems here is that a lot of people think that renewable energy sources can solve our energy needs, and many environmental groups remain opposed to nuclear power.

Advocates of ‘renewable energy’ regularly fail to consider the cost or effort required to satisfy demand. Replacing conventional electricity production with renewable sources is simply not sensible when you look at the amount of raw material (e.g. concrete and steel) that is needed, or at the amount of land that would be needed for the installation. Never mind the fact that solar or wind power are useless in a cold spell of weather like we are having at the moment, so we would still need something reliable to provide power when we need it most. See David Mackay‘s free ebook, Sustainable Energy without the Hot Air, for some clear discussion about the theoretical limits of renewable energy and decide for yourself if you think it’s really a viable option.

I’ve written before about green-groups misguided opposition to nuclear power. Few of them seem to understand the realities of modern nuclear power, which is cheaper, cleaner, safer, and more reliable than it was during the cold-war days of the nuclear arms race. By perpetuating this myth, they are supporting the fossil-fuel industry. How? as Steve Kirsch said recently:

If you want to get emissions reductions, you must make the alternatives for base-load electric power generation cheaper than coal. It’s that simple. If you don’t do that, you lose.

Needless to say, weather-dependant renewable energy cannot provide that base-load, and the only real competition to fossil-fuel is nuclear power. If I were a fossil-fuel CEO, I would certainly want to spread fear of nuclear power, and would happily let the green-groups do my dirty work for me!

If you want a good idea of what it takes to replace fossil-fuel with either renewable or nuclear power, take a look at bravenewclimate.com. They consider the practicalities of cost and build-rate for a range of options, and conclude that anything other than massive deployment of nuclear power simply won’t cut emissions in time.

Until green-groups embrace the need for nuclear power instead of renewable energy, we are not sending a coherent or useful message to world leaders, one that they can use to enact legislation that will genuinely cut emissions. Secretary of Energy Stephen Chu surely understands this, so President Obama must know it too. Small wonder that he couldn’t offer much at Copenhagen when the environmental movement don’t want the changes that will work, and the coal and oil industries are spending a fortune to mislead and misinform the American public.

That’s not to say that this problem is specific to America, it’s a drama that is repeated the world over. The sooner we realise that, the sooner we can start making the changes that matter. Maybe then we can persuade others to do the same too.

How many Physicists does it take to change a light bulb?

Sunday, November 15th, 2009

David MacKay is a professor of natural philosophy at Cambridge University. At the beginning of October he started work for the Department of Energy and Climate Change (DECC) in the UK. He is now their Chief Scientific Advisor, and if you ask me he is clearly the right man for the job.

He’s written a book, Sustainable Energy – without the hot air, which you can download for free from the web (in several formats). Unlike many scientists, he’s an excellent communicator, able to put things in terms that are easy to understand with just a bare minimum of maths. As the book title suggests, he explains a lot about the realities of sustainable energy, in plain english, and with numbers to put it all into context and to set the scale of things.

For example, he converts everything to kilowatt-hours, the amount of energy used by leaving a 1 kW heater on for one hour. By converting everything to the same units, he makes it easier to compare things directly, like the energy you use by driving your car, flying off on holiday, or heating your bath. The kilowatt-hour is also the unit you are charged for on your electricity bill, so it’s something we can all relate to.

He doesn’t have a personal agenda to promote, either. Or rather, he does, but his agenda is to ensure that people can make informed decisions on their own, based on the facts. As he says:

I don’t want to feed you my own conclusions. Convictions are stronger if they are self-generated, rather than taught. Understanding is a creative process. When you’ve read this book I hope you’ll have reinforced the confidence that you can figure anything out.

and

This book is emphatically intended to be about facts, not ethics. I want the facts to be clear, so that people can have a meaningful debate about ethical decisions.

As a scientist, he obviously accepts the concensus view that we need to stop using fossil fuels, and fast. He points out that nine-tenths of the electrical power in Britain comes from fossil fuels, so replacing it means increasing the amount of every other form of energy by a factor of 10, or some equivalent mix.

The British are famous for opposing change. Brits are opposed to having windmills, wave-machines, or nuclear power stations anywhere near them, protest groups will spring up like daisies anywhere you propose to put them. There are currently about 2400 wind turbines in Britain; if we were to attempt to power Britain from wind alone, we would need 600,000 of them. That’s 6 wind turbines per square mile (2.5 per square kilometer). Next time someone tells you that Britain could be powered by wind alone, ask them where they’re going to put all those turbines!

Steel, concrete, and land-use by wind, solar thermal, and nuclear power, from bravenewclimate.com

Steel, concrete, and land-use by wind, solar thermal, and nuclear power, from bravenewclimate.com

Nor is it easy to construct that many wind turbines. They take a lot of steel and concrete to build, and a lot of cable to connect them to the electrical grid. Barry Brook has an excellent article about the cost and effort of building such infrastructure (I’ve borrowed one of his charts, on the right).

Barry is not the only one speaking out, the Institute of Mechanical Engineers have recently criticised the UK government for setting climate-targets without providing the support needed to make them happen. They say there’s no way to build that much new infrastructure without a significant change of strategy.

I’m sure they’re right, but I’m not convinced by some of their proposals for solving the problem, which include carbon capture and storage (as yet unproven) and building ‘artificial trees’ (also unproven technology). I guess engineers would naturally choose an engineering solution! However, they also propose giving much more authority to the DECC, where David MacKay has just started work, and that sounds like a great idea to me.

David has a real knack for putting all these facts and figures into easily understandable forms. But rather than me telling you about him, why not take a look at the video and see for yourself. It’s only six minutes long. (Thanks to Charles Barton of The Nuclear Green Revolution, which is where I found it!)

If you like the video, why not read David’s book, or maybe start with his own 10-page synopsis of it if you’re pressed for time. You’ll get a clear, no-nonsense analysis of what it means to power Britain with sustainable energy, with no politics attached. Though his analysis is specific to the UK, many of the lessons apply elsewhere, of course.

I find it very encouraging that the UK government has decided to listen to David. I hope more people do too, he’s someone we can all understand.