2050 Calculator Tool at DECC

I'm delighted to report that the Department of Energy and Climate Change has published the 2050 Pathways Analysis, which illustrates six possible energy pathways to achieve secure and affordable energy supplies in the UK while still hitting the 2050 target of reducing emissions by 80 per cent on 1990 levels.
These pathways were constructed with the engineering-based 2050 Calculator, which is now available as an online tool, and as a monster-spreadsheet that you can download, play with, and improve.
The Department is encouraging people to enhance this open-source tool, ideally before October 2010, so that it can in due course be used to engage civil servants, politicians, and the general public in 'grown-up' conversations, as Chris Huhne puts it.
The tool allows the user to explore the consequences - in terms of security-of-supply indicators and greenhouse gas emissions - of any combination of demand-side choices and supply-side choices. The intention of this 'play Secretary of State for Energy and Climate Change' approach is not to imply that the energy system could or should be centrally planned, but to help people understand the range of possibilities that are open to us; the trade-offs; the common themes shared by energy pathways that add up; and the scale of action required.
Here's one journalist's reaction to the tool [Independent]. And the Guardian. To understand what's going on behind the simplified front-end, please read the 2050 document and dive into the monster spreadsheet.
I'd like to praise James Geddes and Tom Counsell for their outstanding work in producing this tool, along with Jonathan Brearley, Graeme Cuthbert, Jan Kiso, Katherine Randall, Clare Maltby, and the whole 2050 team at DECC.

Ocean heat content, and useful units

The recent post at realclimate about measured increases in ocean heat content has an interesting graph whose y-axis is labelled in spectacular units, 10²² J. Even exajoules are not that big! (1EJ = 10¹⁸ J)...
One comment on that blog suggested it would be good to re-express in other units that are more familiar - say degrees Celsius, or watts per square metre.
Here goes...
The graph shows the ocean heat content increasing by about 20 x 10²² J in 40 years.
First, let's express the change in heat content as a average rise in temperature of the top 700 metres of the ocean (which is what was actually measured to make these graphs!).

Temperature rise = (Heat content increase) / (Volume of water) /
                         (Heat capacity)
                 = 20 x 1022 J / 
                   (350 x 106 km2 * 700 m) / 
                   (4.2 x 106 J/K/m3)
                 = 0.19 K (or 0.19 degrees C).

Second, let's express the rate of increase in heat content in terms of a net power per unit area required.

Power per unit area = (Heat content increase) / Time / Area
                    = 20 x 1022 J / (40 years) / 
                      (350 x 106 km2)
                    = 0.45 W/m2.

This can be compared with other things measured in the same units - see for example pages 20 and 170 in Sustainable Energy – without the hot air.
Hope this helps!

SEWTHA online - Index added

I've added an alphabetical index page to the html edition of Sustainable Energy - without the hot air. I hope this helps! This index is identical to the version in the paper edition of the book, except that the page-numbers are clickable hypertext links.

Wind farm wakes

I'd like to highlight a stunning photograph and an interesting paper.

The image shows clouds forming in the wakes of the front row of wind turbines of Horns Rev wind farm.
The paper, Wake effects at Horns Rev and their influence on energy production, by Mechali, Barthelmie, Frandsen, Jensen, and Rethore, describes measurements of the effects of these wakes on wind power production.

The message of the paper is interesting. The downstream wind turbines lose 20% or 30% of their power, and sometimes even more, relative to the front row. The spacing of the turbines is 7 diameters.

'withouthotair' - Alternate website

The website withouthotair.com has gone down today (5 Jan 2010) and I am not sure why... anyway, there is a backup website at www.inference.phy.cam.ac.uk/withouthotair/. (Also known as tinyurl.com/sewtha.)
Thanks to friendly people for pointing out the problem.
Apologies for any inconvenience!

Late entry by The Times for the 2009 Hot Air Oscars

In July 2009, I nominated two newspapers for the Hot Air Oscar for Most inaccurate numbers in a right-wing newspaper.
A late submission has arrived, nominating The Times for their laughably inaccurate statement about solar power.
The US Energy Department has calculated that a 62-square-mile (160 sq km) parcel of the Mojave [desert]... receives enough sunlight to power the entire country.

Anyone who has seen SEWTHA page236 will know this statement is wrong. The average power of tropical desert sunshine is about 250 W/m² [see page 46]. Multiply by 62 square miles and you get 40 GW. That is far smaller than US power consumption, which is about 3700 GW (if they mean power in all forms) or 420 GW (if they mean electricity only).
Being more realistic, we should use a power per unit area of 15-20 W/m², since that's what real solar power stations offer. At that power per unit area, 62 square miles would give you just 2.4-3.2 GW.
What is it about journalists, areas, and squares? One of the ealier nominations for this Hot Air Oscar also featured an incorrectly reported area!

Eat bacon and ride a bike!

About 8 months ago, I made a short video with the help of Cambridge University, called "how many lightbulbs" [1]. This week, Cambridge University has published another 6-minute video in the same series - it's fantastic, and it's called Professor Risk. ← click this link to go to the movie in its own page.

The Energy Game

Some super people have been developing ways of presenting energy numbers and engaging the public and policy-makers in consensus-building conversations.
The next 'Energy Game' will take place at the Science Museum in London at the Dana Centre on 3 Dec 2009 at 7pm-9pm, organized by Serious Change.

How to boil water - the sequel

One year ago, I wrote a blog titled how to boil water, which linked to a short essay, "how much is inside hot water?". Over the subsequent 12 months, a flood of emailers have requested that I answer their follow-up questions: "does it make any difference if the lid is on the pan?" and "how does a microwave compare with the pan and the kettle?". Dutifully, I did experiments this Sunday, and this link describes the results in full.
The conclusions are that keeping the lid on the pan while boiling water saves about 3%; and that the microwave is a hopelessly bad way to boil water for making pasta.

Challenged by Carbon

I'm reading Challenged by Carbon: The Oil Industry and Climate Change by Bryan Lovell.
Bryan Lovell is a geologist who has worked in academia and the oil industry for decades. This is an unusual book, intertwining two stories, one of them 55 million years old, and one less than 55 years old. I've not heard either story told before, and both are fascinating.
For the older, slower story, Dr Lovell delves into the details of the geological history of Iceland, the North Atlantic, and the North Sea. He describes how local heavings of the planet's stomach have caused a sub-ocean ridge between Scotland and Iceland to slightly rise and fall, having knock-on effects on ocean circulation and global climate; how slight variations in the average intensity of sunlight in the Northern hemisphere cause changes in climate on a timescale of 20,000 years which can be detected in sedimnetary rocks; and, crucially, how a large natural rapid release of carbon into the atmosphere, 55 million years ago, led to an enormous global warming event, raising the temperature of the water at the bottom of the ocean by more than 4 degrees C within roughly 10,000 years.
The younger, rapidly-moving story is the `insider's view' of how the oil industry, in the last 15 years, changed its mind about human-caused climate change. Starting from positions of climate inactivism (by which I mean "yeah, it may be true, but there's lots of uncertainty and there's no point doing anything, and we oppose greenhouse-gas-reduction treaties") or outright denial, the big oil companies, driven by the science, changed their tunes. First, in 1997, Shell and BP, then, in 2004, ExxonMobil came round to the view "that there is a big problem and that urgent action is required". Lovell knew all the key players well, he was there at the dinner-table discussions where this "Atlantic divide in Big Oil" heaved to and fro, and he hints at the bruising personal conflicts that took place as the oil experts argued about the science. Lovell identifies a particular BP-ExxonMobil debate held by the Geological Society's Petroleum Group in London in 2003 as a turning point in the argument, and describes at length this conversation, whose backdrop was the start of the 2003 Iraq war.
The two stories are connected in multiple quirky ways: the ancient global warming event was probably associated with an uplifting of Scotland that led to the deposition of the North Sea oil fields, from which the oil-folk derived much of their recent wealth; and, more significantly, Lovell describes the 55-million-year-old global warming event as one of the pieces of evidence that helped swing the climate-change argument: oil-men believe what they see in the rocks, and those rocks give uncomfortable evidence for what happens when a large amount of carbon is suddenly released into the atmosphere.
Both stories have the feeling of incompletely-solved detective mysteries. Where did the carbon come from in the ancient global warming event? Was it methane hydrates? Volcanoes? Or some other form of carbon deposit? Was it Iceland that precipitated the global transformation? As for the present-day conversion story, Lovell leaves the reader wondering whether the detective story is yet over - yes, some oil companies greened up their public facades in 2003, but have they reverted to business as usual behind the scenes? And what about the rest of the oil industry?
In the second half of the book, Lovell indicates how he hopes the drama will unfold: "government intervention is essential" in relation to the transition to the low-carbon economy; "concerted action" is required from all oil companies; oil companies should turn their remarkable technical skills to a new waste management business: capturing and storing carbon, especially carbon from coal power stations.
Now, I love physical numbers, so let's recap some of the key numbers for carbon capture. A standard unit of carbon capture and storage is "the Sleipner": thanks to Norway's implementation of a carbon-emission tax of $55 per tonne of CO<sub>2</sub> (which can be compared to today's EU market price of 14.10 euros per tonne), StatoilHydro is storing 1 Mt CO<sub>2</sub> per year in the Utsira saline aquifer under the North Sea. A 1-GW coal power station, running all the time, produces roughly 7 Mt CO<sub>2</sub> per year. So every 1-GW power station would require roughly 7 Sleipners, and the cost to the consumer for electricity from that source might be in the ballpark of an extra 4p per kWh of electricity (similar to the present subsidy for wind power in the UK). The scale of the waste to be stored is worth mentioning. The volume of 7 Mt CO<sub>2</sub> (the approximate annual waste from 1 GW coal power station), after it's been compressed to the same density as water, is three times the volume of the great pyramid at Giza. If Britain were to build, say, 33 GW of `clean coal', the volume of compressed waste that would have to be pumped through pipelines and into rocks under the North Sea would be 100 great pyramids per year; or, to put it in personal terms, 13 litres per day per person in the UK, every litre of this waste CO₂ having the same weight as a litre of water.
This book is fascinating reading.
David MacKay, 18 October 2009

Regenerative braking works!

I had a brilliant tour of the Modec electric delivery-vehicle factory in Coventry, and they let me take a one-hour test-drive in an instrumented vehicle (pictured above).
The vehicle had perfectly good acceleration and its response to the pedals has been engineered to make it feel just like a 'normal' vehicle.
For me the most exciting details from the data from this 3.5-ton vehicle were: 1) three headline numbers - maximum power 80 kW; maximum regenerative power 20 kW; typical power at top speed 40 kW; 2) one nicely measured deceleration event from top speed to zero, which allowed an estimate of how efficient the regeneration is at capturing kinetic energy (the answer was that it was better than 50%; and the Modec engineers mentioned a redesign of the transmission that might further improve this efficiency). 3) overall regeneration figures, showing that the regenerative braking recovered roughly 15% of the energy used during the whole test-drive. The graph above shows by the green area the energy recovered, and by the red area the energy that went out from the battery.
Thank you, Modec!
Full story with factory tour images and data

The carbon-neutral flexible friend - Hot Air Oscar nomination for Barclays

Oh dear... The 'green' twaddle keep on pouring out of the commercial world...
Theo Markettos writes: "I'd like to nominate Barclays for a Hot Air Oscar:
We've launched a new carbon-neutral debit card, which is being rolled out to our debit card users as their current ones expire. ... blah blah ... The Carbon Neutral Company ... blah blah ... reduce carbon emissions in the developing world.
This effectively balances out the harmful emissions of the card's manufacturing process by preventing the release of the same amount of greenhouse gases somewhere else."
Theo continues: "Given the huge influences economics and finance can have on behaviour towards climate change, I'm so glad this bank is focusing on the contribution of the small piece of plastic, silicon and epoxy in my pocket."

Yes, indeed - a fine nomination for the Hot Air Oscar for best emulation of bailing the Titanic with a tea-strainer.

The future of energy

The International Herald Tribune and New York Times published an article featuring my energy consumption versus population density diagram.
Here is the article -
Illuminating the Future of Energy
and here are several alternative versions I made of the diagram -

• showing lots of countries
  
• showing a minimal set of countries
  
• showing lots of countries, including colour-coding by continent
  
• enlarged view showing lots of countries and green lines indicating the power density of renewables
  

Servants, LEGO, and Kindles

I'm happy to announce that Sustainable Energy - without the hot air is now available for the Kindle. A lot of Kindle users have been asking for this. I hope it works nicely!
Some helpful correspondents sent me some nice links to other people's estimates of the energy output of a human slave. I've added these links to the SEWTHA wiki. If you have additional data or facts relevant to the book, please add them to the wiki. Thanks!
And last but not least, I've been brainstorming with friends about how to make games for understanding energy and for consensus-building. One such game has already been designed using lego to represent energy inputs and outputs.

A new graph, showing countries' power per unit area

When I gave my energy talk in Cambridge two weeks ago, one member of the audience objected to my figure (page 13) showing per capita emissions by country. It would be fairer, she said, to show the emissions or energy consumption of each country per unit land area. (Guess her nationality... Australian!) I've made a few figures following her suggestion, and I'm displaying my favourite here. This figure shows population density on the horizontal axis and power consumption per person on the vertical axis. The diagonal green lines indicate the power consumption per unit land area, in W/m². This is precisely the same unit in which I measured or estimated the power per unit area offered by renewables (page 112). Most renewables offer between 0.5 and 5 W/m².
Conclusion: All countries whose power consumption per unit area is bigger than 0.1 W/m² are countries who should expect renewable facilities to occupy a significant intrusive fraction of their country, if they ever want to live on their own renewables. Countries with a power consumption per unit area bigger than 1 W/m² (eg UK, Germany, Japan, Netherlands, Belgium) would have to industrialize most of their countryside, if they want to live on their own renewables. Alternatively, their options are to radically reduce consumption, use nuclear power, and/or to buy renewable power in from other countries.

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(Image can be downloaded from here)

Air traffic visualized

There is a very nice you tube video showing all planes flying during a 24 hour period. I have extracted a frame every 5 seconds to make an animated gif which you can view on this page - I find that my animated gif, which goes about 60 times faster than the youtube video, allows you to perceive some things that are hard to perceive in the video.

"Diluted" Carbon dioxide is "less harmful" - Hot Air Oscar nomination

Get ready to splutter with astonishment... This Reuters feature about UK Carbon Capture and Storage, featuring the switching on of a new OxyFuel combustion burner contains an astonishing sentence:
The Doosan Babcock burner will not attempt to store CO₂ but release it in a diluted, less harmful, form into the atmosphere.
Presumably a Nobel prize is in order, for the discovery that the climate-change impact of CO₂ is reduced by diluting it.
I'm not sure to whom this Hot Air Oscar nomination would be directed - to Doosan Babcock? to the journalist? - but anyway, this must be a strong contender for the Hot Air Oscar for most jaw-dropping twaddle about greenhouse gas emissions.

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Thanks to Paul for the nomination.

Eco eco eco! And super-efficient too (Hot air oscar nomination)

A Hot Air Oscar nomination for boldest appropriation of the word eco goes to Australian company "todae" for their promotion, in their "eco-lighting" section, of "Super Efficient" Halogen 35W downlights. Their product description explains how awful standard halogen lights are, wasting 80% of the energy as heat. These super-efficient halogen replacements for halogen bulbs will save 30%.
Now, it may seem harsh to nominate an energy-saving product for the Hot Air Oscar when there are so many other "eco" scams out there which save much less energy than this (for example, BMW's "EfficientDynamics" innovations). Well, please keep the nominations rolling in. I notice in Toady's web page (just to the right of Galadriel there) that they are also promoting miniature solar panels. Perhaps more nominations can be harvested right here!

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Thanks to Carl Myhill for the nomination.

Wouldn't it be better? No, I don't think so! (Hot Air Oscar nomination)

The website realtimecarbon.org encourages people to be aware of the carbon intensity of the grid, saying "Wouldn't it be better if we could use power when it's greenest?". I am pretty sure that the answer to this question is No!
Imagine, for the sake of simple discussion, that we have a country in which on average half the electricity comes from baseload nuclear power (intensity, 20 g/kWh) and half from demand-following gas (470 g/kWh). And that at night, demand is 60% of the average, and 83% of the electricity comes from nuclear. And that in the day, demand is 140% of the average, and 36% comes from nuclear.
Under these assumptions, the nighttime grid intensity is 95 g/kWh, and the daytime grid intensity is 310 g/kWh.
People using the RealTimeCarbon service will be advised by the red flashing "carbon alert" icon to avoid using electricity during the day, and will be rewarded with feelings of green smugness if they go to great lengths to use electricity at night instead. They may delude themselves into claiming that they have reduced their carbon footprint. You could even imagine them selling carbon offsets based on this sort of electricity-consuming time-travel. But, in the cartoon world that I have just described, the time at which you use electricity makes no difference at all to the carbon emissions! Imagine that 1000 people all earnestly follow the RealTimeCarbon guidance and turn on their 1kW toasters in the middle of the night instead of during the day. What happens? Well, in response to the increase in demand, an extra 1MW of electricity is generated while their toasters are on; and this electricity (in my cartoon world) comes from the gas power stations being turned up just a little bit, whether they turn their toasters on at night or in the day. The true marginal impact of their consumption is 470 g per kWh, whenever they consume.
Now, I am not saying that this cartoon is a faithful representation of what's going on in the UK. Maybe in the UK there are some times of day that are "good" times to use electricity, and others that are "bad". But I think this cartoon proves that "knowing the grid average" doesn't tell you anything useful about that. And I think that the cartoon is a fairly good cartoon of the UK, since in the UK much of the really low-carbon electricity is wind and nuclear, both of which are (at present) not demand-following.
Moreover, I think that if people go to great trouble to check RealTimeCarbon for guidance on "when it is ok to consume", the end result may be a worsening of the UK carbon footprint! Here's two arguments why:
(1) I can imagine people inconveniencing themselves in order to switch on their equipment at night - their inconvenienced lifestyle may well use more energy (for example, when they wait up late for the RealTimeCarbon to go from red to green, they may keep the lights on for longer at night!);
(2) If people think that their electricity is "green" they may give themselves permission to consume more of it. (I know some people argue, for example, that "their electric car is powered by wind, therefore they can drive as much as they want, and it doesn't do any harm to the planet".)
I therefore nominate RealTimeCarbon for a Hot Air Oscar for "Best intentioned but most useless consumer-engagement".

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Thanks to Kim West for pointing me to the website and asking questions.

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PS - I posted a message on the realtimecarbon forum 3 days ago, querying another aspect of their methodology, and there has been no response.

Table for one

INCPEN, The Industry Council for Packaging and the Environment, have produced a super leaflet called Table for one. It is a detailed document full of numbers estimating the energy footprint of one typical British person's food.
All the numbers are expressed in MJ per week. There's lots of nice diagrams, some showing the breakdown of the energy footprint of, say "Snacks" between food supply, primary packaging, transport packaging, transport from factory, retailing, travel to shops, home storage, and home cooking; and some showing summary numbers.
The one below summarises how much energy the average person gets from all their food (73 MJ/week (2.9 kWh/d)), how much it costs to produce and deliver it (337 MJ/week (13.4 kWh/d)) and how much energy is used to produce the packaging (35 MJ/week (1.4 kWh/d)).

The final figure below shows the breakdown of the footprint by food type, and there is a clear message about meat consumption (as I guessed in my book): meat has a bigger energy footprint than any other foodstuff. [They were assuming that the average person gets 7 MJ per week (1,700 calories per week, or 242 cal per day) of energy from meat; this is a weight of 1029 g per week (147 g per day). For comparison in Ch 13 I assumed a carnivore ate 227 g per day.]

It's nice to see an industry publishing such clear energy-footprint numbers! A copy of "Table for one" (pdf) is sitting on my website. I assume INCPEN don't mind my sharing it there.

Moon, and Age of Stupid

This post is fairly off-topic for a sustainable-energy blog, as it is a review of a film that I enjoyed, and would like to recommend. Moon is a film about the life of a man, Sam, working for the biggest eco-energy company, mining helium-3 on the moon.
I am happy that all I knew about this film was that "Sam was lonely on the moon". The only review I read was Roger Ebert's, and he (good for him!) didn't spoil the movie by revealing its plot.
I recommend that you read no reviews of the film (apart from Ebert's), and don't even watch trailers for this film. Even looking at the strap-line on a poster for the movie may reveal more about the movie than you really want to know.
To make this post increasingly on-topic, I'd also like to recommend Age of Stupid. I wrote a review of it after seeing its UK premiere, of which I quote the opening paragraph here.
"The Age of Stupid" is a splendid film. Here's what sets it apart. Whereas many documentaries interview each subject briefly, on a single topic, "Stupid" slowly unveils each character and their web of relationships. The principal characters are real people, whose life-stories relate to the topics of climate change, energy policy and consumerism in multiple fascinating ways.
Both are great films, thoughtful, with twists, and thought-provoking.