Ideas

The Demotechnic Index: Human Energy Units

What if it was easy to compare energy from the food you eat, exercise you do, fossil fuels you burn and household electricity you use?

By Ted Mitchell
Published April 11, 2011

Does the concept of energy seem confusing to you? Can you envision a joule, calorie or kilowatt hour? What if it was easy to compare energy from the food you eat, exercise you do, fossil fuels you burn and household electricity you use?

Fortunately, there is such a human scale unit that makes intuitive sense. It assigns this unit as the amount of energy contained in the yearly food requirement for the average person. These "demotechnic units" were conceived by a local scientist, Dr. J.R. (Jack) Vallentyne.

Of Mice and Men

Dr. Vallentyne was a limnologist, a scientist who studies fresh water lakes. In his career he promoted the ecosystem approach, lobbied for phosphate reduction and helped establish the experimental lakes in northern Ontario, famous for acid rain research. He even took his message to school children under the alter ego of Johnny Biosphere.

Unfortunately in 2007, Vallentyne was diagnosed with late stage cancer. Three days before he died, Jack signed a little book for my wife, who was briefly his physician, along with a scrawled cartoon Earth.

The book was called "Tragedy in Mouse Utopia". The title comes from a 1968 experiment that placed eight mice in an environment of perpetual plenty and watched them thrive until a peak population of 2200 was reached after a year and a half.

Even before the peak was reached, social dysfunction started building and soon was enough to doom the whole colony to extinction in less than 5 years. At the height of population, food was still being provided and 20% of the mouse apartments were still empty. It was not lack of resources or overcrowding, but the environment of plenty that led to social breakdown, essentially forgetting how to be mice.

The parallel is that the energy glut which fuelled the 20th century's human population, economic and technological explosion, could have a similar ending for humans.

Demotechnics

A real nugget in the book is the term Vallentyne called Demotechnics, from Greek demos (population) and techne (technology). A demotechnic unit is the amount of food energy consumed by the average adult human in a year, something everyone can envision.

For the record, it is 2,333 kilocalories per day for a year, 3.56 gigajoules, or 990 kWh.

Demotechnic units, or D units are a very useful comparison tool for different types of energy. For example, 1 D unit is equivalent to a 113 W bulb burning all year, or 102 L of gasoline, or 210 kg of rice, or 95 kg of body fat (so those contestants on 'The Biggest Loser' start out carrying about a year's supply of energy).

Expending 1 D unit of energy will take you 60,690 km by bicycle, 2205 km with a Toyota Prius, 946 km with a Camry, or 500 km with a Sequoia (at Transport Canada rated city mileage minus 20%).

As a case study, let's look at this guy:

Greg Hill (Image Credit: Stayoutdoors.com)
Greg Hill (Image Credit: Stayoutdoors.com)

This is an astoundingly energetic fellow from BC by the name of Greg Hill who just finished climbing and skiing a record 2 million vertical feet (610 km) in a year. This is like climbing the total height of the CN tower three times a day, every day, all year. In potential energy, that is 80 kg x 9.81 m/s2 x 609600 m = 478 megajoules. Human legs are about 20% efficient on stairs, and backcountry snow and variable slope probably cuts this in half again. Add 10% for skiing down, and you have 1.5 D units. So Greg has to eat 2.5 times normal intake, about 6000 Calories a day.

But Greg doesn't live on the base of the mountain in Revelstoke, and has scaled several other peaks as well as spending the summer in Chile. If he drives 30 km round trip to the base on average, 300 days a year, at the usual city mileage minus 20% with his Subaru, that's about 12.5 D units. A flight to Chile, 11,000 km from Revelstoke, racks up about 10 D units round trip, assuming airliners get 50 USMPG per passenger.

Greg Hill's 2 million vertical foot energy consumption
Greg Hill's 2 million vertical foot energy consumption

The cost of energy and food per D unit is interesting.

Dollar Cost of Energy
Energy Type Common unit Cost (US$) Energy (Joules) US $ per D unit
Gasoline (regular) litre 1.25 3.48E+07 128
Coal (lignite) metric tonne 121.14 2.79E+10 15
Natural gas (henry hub) thousand cubic meters 147 3.90E+10 13
Oil (west texas) barrel 104.32 6.12E+09 61
Electricity (US ind. average) kWh 0.099 3.60E+06 98
Electricity (US res. average) kWh 0.11 3.60E+06 109
Electricity (Euro res. average) kWh 0.17 3.60E+06 168
Rice metric tonne 535 1.70E+10 112
Wheat metric tonne 270 1.70E+10 57
Beef (hoof) pound 1.94 7.60E+06 910
Swine (hoof) pound 0.83 7.60E+06 389
Actual food cost day 5 9.77E+06 1824

The cheapest food source is currently wheat, which is still about four times more expensive than non-renewable coal and natural gas. Record oil price was $147 in June 2008. Natural gas peaked at $456 also in June 2008, so it is capable of even greater price spikes than oil. Note that electricity produced from burning fossil fuels operates at about 40% efficiency, so that each unit so produced actually represents about 2.5 units of thermal energy.

Demotechnic index

The demotechnic index (DI) is the ratio of a country's total technological energy consumption per capita to the D unit of physiological (food) consumption. Hunter gatherer humans have a DI of 0, that is, they consume only enough to feed themselves and harness no other energy source. Pre-industrial societies could enlarge that energy use by including the work of water and wind power and beasts of burden, but we're still talking single digits.

Canada in 1990 had a DI of 118, which is an astounding amount of energy that we clearly take for granted.

The DI has grown rapidly in the last century for industrialized countries.

Demotechnic Index and Consumption adjusted population by country, 1990
Rank Country Demotechnic Index Population (000) Demotechnic Population (000)
1 Qatar 198.5 368 73,412
2 UAE 163.4 1,589 261,200
3 Bahrain 128.5 516 66,822
4 Canada 118.1 26,521 3,158,916
5 Norway 109.2 4,212 464,331
6 United States 91.3 249,224 22,993,406
7 Iceland 83.2 253 21,310
8 Sweden 78.6 8,444 671,720
9 Kuwait 68.2 2,039 141,038
10 Finland 65.7 4,975 331,982
11 German Dem Rep 64.5 16,249 1,064,310
12 Australia 63.4 16,873 1,086,959
13 U.S.S.R. 57.3 288,595 16,827,974
14 Belgium 55.8 9,845 559,590
15 Netherlands 55.7 14,951 848,320
16 New Zealand 55.5 3,392 191,512
17 Czechoslovakia 53.3 15,667 850,561
18 Saudi Arabia 52.3 14,134 752,777
19 Germany, Fed Rep 49.8 61,324 3,112,193
20 Trinidad & Tobago 47.0 1,281 61,526
21 Switzerland 45.9 6,609 310,160
22 United Kingdom 44.4 57,237 2,596,270
23 France 44.1 56,138 2,533,508
24 Bulgaria 43.0 9,010 396,170
25 Austria 42.6 7,583 330,543
26 Singapore 40.9 2,723 114,066
27 Denmark 40.7 5,143 214,617
28 Romania 39.0 23,272 931,345
29 Japan 37.8 123,460 4,784,075
30 Poland 37.7 38,423 1,485,049
31 Hungary 35.6 10,552 386,414
32 Italy 34.1 57,061 2,000,559
33 Libya 33.3 4,545 155,848
34 Ireland 30.4 3,720 116,696
35 Oman 28.2 1,502 43,843
36 Venezuela 27.1 19,735 554,356
37 Greece 26.8 10,047 279,106
38 Korea, DPR 26.5 21,773 599,193
39 Israel 24.7 4,600 118,312
40 Spain 24.4 39,187 993,782
52 Mexico 15.3 88,598 1,439,718
55 Brazil 14.0 150,368 2,255,520
79 China 7.2 1,139,060 9,328,901
109 India 3.6 853,094 3,907,171
121 Haiti 2.9 6,513 25,466
142 Bangladesh 1.3 115,593 260,084
143 Cape Verde 0.8 370 681
144 Comoros 0.4 550 765

From: Consumption: The Other Side of Population Paper prepared for the International Conference on Population and Development Francisco J. Mata, Earth Council Larry J. Onisto, Ontario Hydro. J. R. Vallentyne, Canada Centre for Island Waters.

Note: countries of similar economic standing vary widely in energy consumption, for example Germany has twice Canada's population but similar standard of living and the same total energy use. Since this data is out of date, I ran some ballpark numbers and it appears that Canada hasn't changed much, although China and India are now much bigger contributors.

The Globe in Demotechnic Distorted Geography

Consumption adjusted population cartogram resizing each nation by the ecological load they exert on the planet through their population multiplied by the effects of consumption.
Consumption adjusted population cartogram resizing each nation by the ecological load they exert on the planet through their population multiplied by the effects of consumption.

From: Consumption: The Other Side of Population for Development (May 2010 draft update, unpublished)

What will Canada's future hold?

There are several other scales such as the carbon footprint, and human development index, and all of them have their advantages. None of them really put a hard number to the kind of use, or waste, that the DI does.

Another way of looking at this is the unofficial (but very useful) statistic Gross Domestic Product per Barrel of oil equivalent, which can be used to rank the 'dollar energy efficiency' of a country's economy.

Not surprisingly, Canada ranks high on the DI (undesirable) and low on GDP/BOE (undesirable), in fact is the worst of the large first world economies on both of these scales.

If energy prices are low, being energy wasteful can actually be good for the economy, as most economic activity requires or is at least leveraged by energy use. But if prices continue to rise relative to the rest of the economy and Canada cannot make rapid improvements in efficiency, non energy producing sectors (and regions) could be out-competed by every country on the above list.

Canada could end up demoted to a second class economy. Indeed, with Canadians increasingly embracing regressive leaders like Rob Ford, we are making our beds to do just that. Will we end up like the oil producer nations of Saudi, Venezuela, and Nigeria that have energy wealth but little else? If we keep the status quo, the future is fairly predictable: Alberta's oil patch and other energy producing areas flourish, and the rest of Canada slowly rusts into irrelevance, especially outside of the larger cities.

I really think the key to turning this ship around is getting serious about a carbon tax.

The Happy Medium

I have a pet theory, likely inherited from my father, that there is an optimal level for just about everything. Energy is extremely useful for enhancing our lifestyle, but is it too cheap and too easy to burn away? Based on our behaviour for the last half century, I'd say absolutely yes.

We always have choices: Cycle or drive, apartment or mansion, urban or suburban, local or imported, Canadian or exotic vacation, kayak or seadoo, ski or snowmobile, rake or leafblower. For every lifestyle choice comparison, I tend to favour the lower energy choice, not because it makes me feel conscientious but because it is almost always more fun or at least better for the body and soul.

I think Jack would agree.

Bibliography

Vallentyne, J.R.: Tragedy in Mouse Utopia http://www.trafford.com/Bookstore/BookDetail.aspx?Book=181860

Consumption: The Other Side of Population, Paper prepared for the International Conference on Population and Development 1994, Francisco J. Mata, Earth Council, Larry J. Onisto, Ontario Hydro. J. R. Vallentyne, Canada Centre for Island Waters.

Personal communication: Thanks to Doyle Crosswhite and Larry Onisto for making this article and a 2010 draft update available respectively http://www.sci.sdsu.edu/salton/MataConsumption.html (the link to the above article is dead)

Note: Energy price data is current as of April 4, 2011 or the most recent available month

Dollar cost of energy calculations are available on request

Ted Mitchell is a Hamilton resident, emergency physician and sometimes agitator who recently completed a BEng at McMaster University. He is fascinated by aspects of our culture that are harmful, but avoid serious public discussion.

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By banned user (anonymous) | Posted April 11, 2011 at 21:00:20

comment from banned user deleted

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By Undustrial (registered) - website | Posted April 11, 2011 at 22:42:55 in reply to Comment 62071

Good question.

Colder climates definitely play a role in Canada's leading place among carbon emitters worldwide. We'd be in a very different situation right now if we could grow crops year-round and survive without winter heating like many American States.

On the other hand, the correlation between the rich and poor nations worldwide that they're often spoken of as "the global north" or "south". There are some very clear historical reasons why Europe is far more "developed" than Africa, or North America than South. Colonization produces winners and losers, and in the end even those who didn't colonize and weren't colonized did far better to be near the conquerors.

So can we change? That's up to us. We know how to build homes for this climate that require little or no energy. We just don't. But we could.

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By BobInnes (registered) - website | Posted April 11, 2011 at 23:09:21

Fascinating! I always wondered how metabolism is measured. It seems some folks eat lots and can't put on weight, others seem to put on weight just looking. Any thoughts?

I once had occasion to read Hammurabi's Law Code. It stipulated that a farm labourer must receive what I figured was about 15-18 barrels of corn annually although the different conversions were very problematic - maybe someone has a more accurate source. I guess this must have included an allowance for wife, children, pregnancy, etc. Plus, I guess the labourer would have had to trade some corn for other necessities (clothes, building materials.) I was trying to get a handle on what a real minimum wage might consist of in material terms.

Is the price of gasoline and methane really that different (order of magnitude)? Seems like they're not that wide apart where taxis fill up?? Wholesale vs retail?

BTW, if I place a copy of this article under the sink, do you think the resident mice will take the hint ?;-)

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By Undustrial (registered) - website | Posted April 12, 2011 at 10:43:31 in reply to Comment 62078

Just a note - it probably wasn't corn (New World crop) and would have been wheat, barley or rye. Nice to hear that they had a minimum wage, though.

As for methane v. gasoilne, whatever the price difference now, methane is FAR easier to produce - even with nothing but humans, green waste or draft animals.

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By Jacob (registered) | Posted April 12, 2011 at 11:40:12

this is a fantastic article Ted, thanks.

Seems to me Canada has become an emirate, economically, yet unlike the sheikdoms we let corporations take most of the wealth. So we get the worst of both worlds: resource dependency hindering innovation, controlling government, and destroying environments, but none of the goodies.

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By Mr. Meister (anonymous) | Posted April 12, 2011 at 13:57:09 in reply to Comment 62096

Canada is a lot of things but an emirate? Please.

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By Undustrial (registered) - website | Posted April 13, 2011 at 11:21:35 in reply to Comment 62102

I wouldn't call it an Emirate. Most Emirates don't have world-leading supplies of water, forest products and prescious metals. Canada is, on the other hand, one of very few resource-rich First World countries. And given the amount of resources extracted and how little we charge in royalties, there are certainly a lot of Third-world parallels one could draw. And the farther north you go, the more true this becomes.

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By Ted Mitchell (registered) | Posted April 14, 2011 at 22:21:07

Climate is definitely a factor. But all these peer countries do better. Even Norway, which is a huge natural gas exporter.

More recent data from the "Economist 2010 pocket world in figures" for colder climates:

Country $GDP/cap

%Urban

Energy consumption/capita(kg oil = D-unit, % of 1990)

Net imports(%usage) (+ = importer; - = exporter)

Canada 40330

80.3

8262 = 107.5 (91% of 1990)

-53

US 45592
81.4
7770 = 101.1 (111%)
+29

Denmark 57050
86.4
3850 = 50.1 (123%)

-41

Finland 46260 63.0
7108 = 92.4 (141%)
+52

Norway 82480
77.5
5598 = 72.8 (67%)

-754

Sweden 49660
84.5
5650 = 73.5 (93%)
+36

UK 45440
89.9
3814 = 49.6 (112%)

+19

Germany 40320
73.5
4231 = 55 (110%)
+61

China 2430
42.2
1433 = 18.6 (259%)
+7

(using 76.9 kg oil/D-unit) Couldn't find comparable climate data. But for example, Oslo Norway mean temp 5.9 C, while Canada's mean population center is in the US side of lake superior, nearest data: Marquette MI mean temp 6.1 C.

Percent urban is included because cities are more energy efficient per capita.

Comment edited by Ted Mitchell on 2011-04-14 22:39:40

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By Ted Mitchell (registered) | Posted April 14, 2011 at 23:16:47

Regarding weight and food intake, I've discussed it before: http://www.raisethehammer.org/article/42...

Note the hyperactive person example, it shows that a fidgety Phil burns off more calories than a dedicated runner, because they spend less time sitting but most of the day at slightly increased intensity (which seems like nothing to them). I've since learned from a study that even with equal time spend sitting and exercising, the person who is always up and down, never sitting for long periods will burn off more energy even though the total amount of exercise is identical to people who sit for longer periods at a time.

Beware of Oreos: Eating 1 Oreo cookie more than you need to every day = 60 Cal, so 1 D-unit (95 extra kg) is achieved after 39 years. So if energy burnt off does not change, starting at age 18 with one extra Oreo per day, a 70 kg man could become 165kg morbidly obese by age 57.

But it's not that simple. Some people will burn off that extra oreo more easily, maybe due to enhanced leptin activity.

Energy expenditure in response to the extra Oreo is also non linear and unpredictable. If you continue to do the same thing every day, as you get heavier it takes more work to move around. But past a certain point you just can't do it, slow down, get arthritis, drive more, use a scooter etc, and then you're drastically reducing energy expenditure.

Basically, thin people who eat a lot are constantly doing a lot of activity that they never consider as work, while heavy people who appear to eat normally either are eating more than they think (e.g. Oreo snacking really adds up!) and/or do less activity than they think, such as spending long periods inactive and perceiving any activity as more work than it is.

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By Ryan (registered) - website | Posted April 15, 2011 at 09:25:52 in reply to Comment 62318

Beware of Oreos

Further to this, I highly recommend the following lecture on sugar by Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology:

http://www.youtube.com/watch?v=dBnniua6-...

It includes a fascinating look at the effects of just one bottle of Coke a day.

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