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Ch 26 Page 199: Sustainable Energy - without the hot air

Thu, 08 Oct 2009 16:37:35 -0000

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Isn't this a little unfair to compressed air? Light containers might be developed, if they haven't been already. Would you consider adding the raw figure? - Keith Bradbury

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by: Keith Bradbury

Can we clean King Coal and live happily ever after?

Fri, 11 Sep 2009 08:46:24 -0000

Comments:

Many of you will have heard David MacKay interviewd this morning on Today - a good moment to pick up our group read again after a v.long summer break. We should aim to finish by Copenhagen. - tony curzon price

Highlights and Sticky Notes:

David adopts an avowedly arbitrary definition of a sustainable burn rate: can a burn-rate be sustained for 1000 years? If yes, it is sustainable. That definition allow shim to relate the UK's coal reserves with a daily per person sustainable consumption rate --- there would be less than 1 kWh of electricity per person available from clean coal. But we consume 180 kWh/day/person, so clean coal is a stop gap --- it will not see our way of life go on for that long.

This relies pretty crucially on the definition of sustainability, which I think is wrong for the purpose. David adopts what one might call the Ise Shrine notion of sustainability. The Ise Shrine was first built in 4BC and has been rebuilt, identically, ever since then every 20 years. It was last rebuilt in 1993. This is "sustainability" as in keeping on and on doing the same thing. David is ISe-esque in choosing our ability to do the same thing - burn British coal - for a very long time to come.

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by: tony curzon price

Ch 24 Page 175: Sustainable Energy - without the hot air

Fri, 21 Aug 2009 08:00:36 -0000

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I added an erratum to the book trying to improve the accuracy of my discussion of the cost of nuclear decommissioning: my error was that I attributed the nuclear decomm. cost to civilian electricity generation, but in fact the lion's share of the clean-up cost is for military mess. C.Duro then posted a comment disputing this fact and accusing me of dishonest presentation. I stand by the fact: I got this same erratum twice from two independent sources, then checked it, and I don't think that the Telegraph article cited by C.Duro disproves the erratum. The lion's share (ie more than half) of the cost is for military clean-up. - David MacKay

The nuclear decommissioning authority has an annual budget of £2 billion. In fact, this clean-up budget seems to rise
and rise. The latest figure for the total cost of decommissioning is £73 billion. news.bbc.co.uk/1/hi/uk/7215688.stm

Now why is this nearly 50% increase over the value quoted in the text tucked into the endnotes? If the text were emphasizing how great a cost this was, the end notes might be appropriate. However, the text main point is that it is a smaller 'subsidy' than that given wind generation. - Ché Duro

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by: David MacKay

Sustainable Energy - without the hot air: Ch 3 Page 30

Sat, 31 Jan 2009 09:19:38 -0000

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It’s been estimated
that making each unit of petrol requires an input of 1.4 units of oil and
other primary fuels (Treloar et al., 2004).

Just to be clear: this means that if I have 2.4 units of "primary fuels" (whatever they are), then I can expect to get 1 unit of petrol out. Quetion -- those 1.4 units ... are they _consumed_ in the refinery process, or are they partly bye-products that can be used for other things? - tony curzon price
No, not 2.4 units, 1.4 units! - David MacKay

The total amount of car travel in the UK is 686 billion
passenger-km per year, which corresponds to an “average distance travelled
by car per British person” of 30 km per day.

I tried to do a quick compare with France. This very attractive site:
http://sansvoiture.free.fr/index.php?menu=textes&sousmenu=autodecroissance
claims 14,000 km per car per year average. At one person per car, driving 250 days per year, we get to 56km per day on average.

I was hoping to say: "High Speed Trains were planned for in 1974 in France; more than 30 years later, their logic becomes clear..." even if this is true, the averages here don't scream it out ... - tony curzon price

I want to estimate
the energy consumed by someone who chooses to drive

I like the idea here; I agree that 'averages' are abused. Somehow similar to everyone believing that they have above average driving skills. However it seems that in using a km/person/day value 66% greater than the average, the calculations later regarding necessary energy production are all suspect (because the total production is simply averaged to a kwh/person/day value). Considering how large a portion of our energy is used by cars, this choice is significant. - Ché Duro

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by: David MacKay

David MacKay FRS: Sustainable Energy - without the hot air: Errata

Fri, 14 Aug 2009 23:37:08 -0000

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The lion's share of the money is thus cleaning up military mess, not civilian-power mess.

Once again I cannot help but feel that MacKay is promoting nuclear power, in spite of his own numbers. Firstly, his own endnote indicates that this £2 bn/year for 25 years is 50% too low. Now he returns to the subject claiming that the 'lion's share' is for military clean up. This article (www.telegraph.co.uk/finance/newsbysector/utilities/2793052/Washington-Group-wins-Sellafield-clean-up-contract.html) indicates that while the majority of the total waste is military in origin, it accounts for only about 20% of the total cost. - Ché Duro

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by: Ché Duro

Ch 19 Page 115: Sustainable Energy - without the hot air

Tue, 21 Apr 2009 21:41:22 -0000

Comments:

OK .. Here is the answer to my earlier quibble doubting the untruth of "every little bit helps" ... - tony curzon price

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a little adds up to a lot,” if all those “littles” are somehow focused into a
single “lot” – for example, if one million people donate £10 to one accident-
victim, then the victim receives £10 million. That’s a lot. But power is a
very different thing. We all use power. So to achieve a “big difference”
in total power consumption, you need almost everyone to make a “big”
difference to their own power consumption.

by reducing our population

I think it's important to note that on current trends the UK population and hence UK energy demands will grow by 10% by 2030 to 70 million. Source UK Government Statistics. - ian d

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by: ian d

Cutting the vampire appliances | open Democracy News Analysis

Sun, 31 May 2009 12:12:12 -0000

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Many gadgets consume a surprising amount of power on standby. David cut his electricity consumption by half by making sure his "vampire appliances" were kept off. There are real savings available here. David and friends set up "ReadYourMeter.org" to try to encourage others to make this sort of saving. According to the International Energy Agency, standby power consumes a surprising8% of residential electricity.

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by: tony curzon price

David MacKay's energy blog

Fri, 15 May 2009 19:09:29 -0000

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Sustainable Energy - without the hot air

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by: tony curzon price

The Economist notices & praises Energy Without Hot Air (Everyone is green now | Meltdown | The Economist)

Fri, 15 May 2009 09:15:56 -0000

Comments:

Hat tip to Paul Mott, from EDF - tony curzon price

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Least woolly of all is David MacKay’s book (which can be bought or downloaded free from www.withouthotair.com). Irritated by the waffle that often surrounds discussions of energy and climate change, Mr MacKay, a physicist at Cambridge University, has chosen to illustrate the challenge of breaking our fossil-fuel addiction armed only with the laws of physics, reams of publicly available information and the back of an envelope.

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by: tony curzon price

Ch 21 Page 153: Sustainable Energy - without the hot air

Sun, 10 May 2009 11:35:20 -0000

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So top-of-the-line air-source heat pumps for warming it is. - tony curzon price

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For forest-dwellers, there’s wood. For
everyone else, there’s heat pumps.

again the whole argument rests on how realistic his COP figures are. - dave woolcock

143The average internal temperature in British houses in 1970 was 13 °C! Source:
Dept. of Trade and Industry (2002a, para 3.11)

I still don't believe it - do you? - dave woolcock

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by: dave woolcock

Ch 21 Page 151: Sustainable Energy - without the hot air

Wed, 13 May 2009 22:19:11 -0000

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In Japan, thanks to strong legislation favouring effi-
ciency improvements, heat pumps are now available with a coefficient of
performance of 4.9.

Am I being cynical in guessing that these figures quoted for COP are peak or best figures? how does the COP vary with external air temperatures that we are likely to see in the UK?... I imagine it is easy and efficient to extract heat from warm air, but what matters is the range -5 to +15C... more COP data please. Otherwise its like car MPG figures. - dave woolcock

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by: dave woolcock

Ch 21 Page 143: Sustainable Energy - without the hot air

Sun, 10 May 2009 11:11:27 -0000

Comments:

Bring the experimental psychologists to the climate change policy table! (And repeat Francis Bacon's "hotness is in the eye of the beholder" experiment) - tony curzon price

Highlights and Sticky Notes:

I do like this method of displaying information. Edward Tufte would be proud ! - dave woolcock

What’s a reason-
able thermostat setting to aim for? Nowadays many people seem to think
that 17 °C is unbearably cold. However, the average winter-time tempera-
ture in British houses in 1970 was 13 °C!

I'm afraid I don't believe the 1970 / 13C assertion. What is its origin? - dave woolcock

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by: dave woolcock

BBC NEWS | Programmes | More Or Less | Counting the Kilowatts

Tue, 12 May 2009 14:53:20 -0000

Comments:

David interviewed on BBC radio about Energy Without Hot Air - tony curzon price

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How much energy does Britain use - and how much could we generate without burning fossil fuels?

Physics professor David MacKay has been doing the sums.

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by: tony curzon price

"Small is beautiful" ... "but big is efficient" in heating systems | open Democracy News Analysis

Sun, 10 May 2009 13:37:54 -0000

Highlights and Sticky Notes:

The average winter-time temperature in English homes in 1970 was 13C. Today, 50% more than that is usually thought of as just about tolerable.

There are three strategies for reducing the carbon footprint of keeping warm: reduce the temperature difference between the inside and outside; reduce heat losses from inside to outside and increase the efficiency with which energy is transformed into heat.

The first two seem obvious and cheap solutions. We hear a lot about "nudging" as a policy, and this seems an ideal area for clever devices to make people aware that they could be heating less and leaking less heat. David does not mention my own favourite long term solution here---a widespread move to small exoskeletons as a substitute to housing: we should be able to walk around with our temperature control close to our bodies and our living spaces open to the elements.

David makes a powerful argument for heat pumps rather than Combined-Heat-and-Power plants, and slips in a big fault-line in eco-politics versus eco-engineering: energy transformation efficiency tends to rise as scale rises, whereas green politics loves to decentralise and make solutions small and local.

This chapter is full of low-ish tech, labor-intensive investments that make energy-efficiency sense today. This is just what government policy should be stimulating our economies with today.

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by: tony curzon price

Ch 21 Page 146: Sustainable Energy - without the hot air

Sun, 10 May 2009 11:18:37 -0000

Comments:

"small is beautiful" ... "but big is efficient" --- a sad fact for environmentalism to come to terms with -- where physics just won't play the politics - tony curzon price

Highlights and Sticky Notes:

A final impediment to rational discussion of combined heat and power
is a myth that has grown up recently, that decentralizing a technology
somehow makes it greener. So whereas big centralized fossil fuel power
stations are “bad,” flocks of local micro-power stations are imbued with
goodness. But if decentralization is actually a good idea then “small is
beautiful” should be evident in the numbers. Decentralization should be
able to stand on its own two feet. And what the numbers actually show is
that centralized electricity generation has many benefits in both economic
and energy terms. Only in large buildings is there any benefit to local
generation, and usually that benefit is only about 10% or 20%.

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by: tony curzon price

Low Carbon Transport: Bicycles, trains, electric cars and nuclear ships | open Democracy News Analysis

Mon, 04 May 2009 19:49:47 -0000

Comments:

Electrify transport. There's not much to beat trains+bicycles, and any government looking for a Keynesian stimulus should find lots of infrastructure opportunities here.

David MacKay comes down softly on the car---which shows great realism---and finds that electrification is the only real solution there. He debunks hydrogen as a good energy carrier. Flying is a really tough case---there is not much that can be done to reduce its energy intensity. (I was sitting in an easyjet plane the other day that tried to convince me of its greenery by saying: "Flying contributes less CO2 than driving to the atmosphere" ...). Batteries are the way to go---though just wait for the peak lithium scares.

David has an interesting aside on nuclear ships. If we could make the (political) world safe for small-scale nuclear power, maybe there's more than ships that could benefit. - tony curzon price

Highlights and Sticky Notes:

Electrify transport. There's not much to beat trains+bicycles, and any government looking for a Keynesian stimulus should find lots of infrastructure opportunities here.

David MacKay comes down softly on the car---which shows great realism---and finds that electrification is the only real solution there. He debunks hydrogen as a good energy carrier. Flying is a really tough case---there is not much that can be done to reduce its energy intensity. (I was sitting in an easyjet plane the other day that tried to convince me of its greenery by saying: "Flying contributes less CO2 than driving to the atmosphere" ...). Batteries are the way to go---though just wait for the peak lithium scares.

David has an interesting aside on nuclear ships. If we could make the (political) world safe for small-scale nuclear power, maybe there's more than ships that could benefit.

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by: tony curzon price

Ch 20 Page 136: Sustainable Energy - without the hot air

Mon, 04 May 2009 19:35:17 -0000

Comments:

Nice congestion charging system. Would make the drive-in cinema expensive. - tony curzon price

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The congestion charge would be proportional
to the number of bleeps received; this charge could be paid at refuelling
stations whenever the vehicle is refuelled. The radio transmitter/receiver
would replace the current UK road tax disc.

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by: tony curzon price

Ch 20 Page 133: Sustainable Energy - without the hot air

Mon, 04 May 2009 19:29:42 -0000

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Long distance travel is a real carbon problem---nuclear powered ships? - tony curzon price

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there is no
prospect of significant improvements in plane efficiency.

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by: tony curzon price

Ch 20 Page 132: Sustainable Energy - without the hot air

Mon, 04 May 2009 19:26:41 -0000

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Peak lithium? - tony curzon price

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the amount of lithium may be
a concern, especially when we take into account the competing ambitions
of the nuclear fusion posse (Chapter 24) to guzzle lithium in their reactors.

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by: tony curzon price

Ch 20 Page 131: Sustainable Energy - without the hot air

Mon, 04 May 2009 19:23:58 -0000

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Electric cars already reduce carbon footprint even before we green the electricity supply. This surprises me. - tony curzon price

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So I conclude that switching to electric cars is already a good
idea, even before we green our electricity supply.

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by: tony curzon price