A human power station from the BBC’s ‘Bang Goes the Theory’ where human energy slaves were made to power a single household for 24 hours

When I started this blog almost three years ago it had a different title to the one you see today. Scratching my head for a good name for it I decided to call it the Peak Oil Dispatch. My idea was to provide a kind of online resource for peak oil news and other articles relating to the decline of industrial life and catabolic collapse. After all, I was unemployed back then and had plenty of time on my hands for such a project.

This idea didn’t last long. Once gainfully employed again I found I didn’t have time for such a project, so I decided to change the name and stick with the traditional blog format. I used the quote from Colin Campbell as a title. There was something about the number 22 that attracted me – I lived in flat number 22 in our block, my phone number started with ’22’ and so did our car registration – and there is irony in the Catch-22 situation our industrial societies find themselves stuck in in that we have to burn more oil to keep growing the economy which will eventually consume all the oil and destabilise the climate.

Colin Campbell, when giving a talk to the Association for the Study of Peak Oil (ASPO) had said that every day oil provides humanity with the equivalent energy of 22 billion human slaves – or ‘energy slaves’. These slaves do our bidding silently and are unnoticed by the masses, and the way he arrived at the figure, I am told, is by taking the total amount of conventional oil produced each day and dividing it up into ‘drops’. Each drop of oil represents the work of one human in one day, and there are around 22 billion drops of oil produced each day.

Alexandre de Robaulx de Beaurieux, a geologist and board member of ASPO Germany, provided me with the following quote from Colin Campbell from the 2013 edition of Campbell’s Oil and Gas Depletion:

"It was as if oil provided us with an army of unpaid and unfed slaves to do our work for us. It has been calculated that a drop of oil, weighing one gram, yields 10,000 calories of energy, which is the equivalent of one day’s hard human labour. In other words, today’s oil production is equivalent in energy terms to the work of 22 billion slaves. Financial control of the world has led to a certain polarisation between the wealthy West and the other countries which find themselves burdened by foreign debt as they export resources, product and profit. Many people have come to think that it is money that makes the world go round, when in reality it is the underlying supply of cheap, and largely oil-based, energy, that has turned the wheels of industry, fuelled the airliners and the bombers, and generally acted as the world’s blood stream. Midas-like wealth flowed to those who find themselves having a controlling position in the System."

The energy slaves in question were assumed to be involved in work that was the equivalent of lifting a ton of sand 2m into the air. This was all very well but I couldn’t help thinking that the number of energy slaves seemed a bit on the low side. After all, if driving an average 120 horse power car down a motorway were to be done with the power of human slaves alone, you would need upwards of 500 human beings to pull you along (assuming they could run that fast!). And with around a billion cars in the world at present, plus millions of trucks, aircraft, ships, trains etc. the figure of 22 billion would seem very low indeed – and that’s not even taking account of all the other uses for fossil fuels that we have, from heating to electricity generation and so on.

So it struck me that we should consider all fossil energy sources when trying to arrive at some figure of how much assistance we are getting from hydrocarbons. Given that I’m no Einstein when it comes to mathematics I asked for help in arriving at this figure, promising the one who could come up with the best answer a box of Cornish fudge. What I wanted to know was the answer to the following question:

If all the energy we currently derive from fossil fuels alone (i.e. not including nuclear or renewables) was suddenly unavailable, and we had at our disposal a few handy nearby planets populated with well-fed healthy adult human males that we could capture as our ‘energy slaves’, how many of them would we need to allow us to enjoy the same lifestyle currently being provided by fossil fuels?

Of course, this being an entirely imaginary exercise, we would have to overlook the fact that the slaves would need to be fed, and furthermore we would have to assume that they produced energy close to the point where it was needed (e.g. a coal power station would be replaced by serried ranks of energy slaves on exercise bikes fitted with power-generating dynamos). A further assumption is that a slave would only be able to work for 12 hours at a stretch.

Of the responses I received three stood out – and they all come to somewhat similar conclusions despite using different methods. 

Daniel Hägerby from Sweden, taking his data from the 2013 BP Statistical Review, concluded the following about how many slaves we would need per capita:

Total amount of primary fossil energy consumed was 10848 Mtoe in 2012. Multiply by 42*10^6 to get the number of kilojules. Then divide by 3600 to get kWh (which I find easiest to think in terms of). Then divide by population, I used seven billion. That gets you a total of about 18 000 kWh per capita per year. Then we assume that each slave works 12 hour per day 7 days per week. We can also assume that each slave can yield 50 watts of productive power. With a human power efficiency of 20% that means each slave would consume 50/0,2*12*365 = 1095 kWh per year. Divide the two and you get about 17 fossil energy slaves per capita. I think ignoring the efficiency of human power conversion is cheating – because engines and power plant also have big thermal losses. So, if our slaves could eat fossil fuels and have no energy expenditure to survive (only to work for us) – we would need 17 slaves per capita, working 12 hour per day all year round. Then we can of course study the UK separately. That would give us around 30 fossil energy slaves, using the same method.

So that means that with around 17 energy slaves per unit of population, we would need a total of 119 billion energy slaves to keep things ticking over as they do today.

Also from Sweden, Gunnar Rundgren, who writes the blog  gardenearth.blogspot.se, pointed out that he had already made such a calculation for his book Garden Earth. He relates the following:

We can contrast the energy content in human beings with the external energy sources conquered, to give us an idea of the importance of the development of external energy sources. Let us do a back-of-the-envelope calculation.  A human being needs around 2500 calories per day (2.9 kWh ). We use around 80% of that just to stay awake, think, eat, sleep, breathe, etc. So a bit less than 600 Wh is perhaps left for work. Hard-working people could perhaps use 800 Wh, but they will also eat more. On a yearly basis, the average person consumes around a million calories, which corresponds to 1.16 MWh.

The average American uses 7.71 tons of oil equivalents (toes) of energy (the average British 3.8, the Swede 5.65 and the Senegalese 0.25), which corresponds to 90 MWh, that is, the energy in the annual food consumption for 77 persons, or if we calculate on the basis of the 20% that we actually use for work it would correspond to roughly 380 persons. On the other hand, energy losses also occur for the conversion of external energy to useful work. If we assume that this is 40%, we arrive at a figure of 150 persons.

So, depending on how we count, each American has somewhere between 75 and 400 ‘energy slaves’ working for him or her, and the richer ones have thousands. The global average energy use is of course lower, and represents figures between 18 and 90, which translated to the total population would mean somewhere between 120 and 600 billion energy slaves. From this perspective, it is certainly no surprise that human beings have taken over the planet!

Another way of looking at it, from an economic perspective, is that a barrel of oil represents the energy of 25,000 hours of human toil, that is, 14 persons working round the year with normal Western labour standards. The cost for pumping the oil is not more than a few dollars per barrel, and even with an oil price of many hundred dollars per barrel, it is very cheap compared to human slave labour. The beauty of the oil slaves is that they don’t have to be fed at all. The slaves of the past, even under huge oppression and extortion, used a lot of the food themselves just to survive. From this perspective, our current wealth can be easily understood and demystified. Even hundreds of years ago, long before industrial society and capitalism, the person who had hundreds of others working solely for him or her could lead a comfortable life.

Any comments? I guess a difference is if you calculate in-energy or output energy for both fossil and human labour?

As Gunnar points out, the calculation is necessarily a very rough one due to the nature of the underlying assumptions. There is no real way to substitute human labour for coal or oil, but his shot at estimating the true number of energy slaves is illuminating.

Finally, Alex from ASPO Germany, who is mentioned above, provided his own calculations, and brings EROEI and the energy subsidy provided by past slaves (i.e. what quality of oil is Colin Campbell assuming in his calculation?) into the conversation. Alex’s way of looking at it uses a different way of arriving at a figure, but the conclusion he reaches is somewhat similar to the first two:

[T]he party with unconventionals is suddenly over as soon as you stop drilling more and more only in order to stand still [Red Queen effect]. So what we have is the good stuff with EROI-ratios over let’s say 30:1 already gone. Now what the Americans do is trying to substitute conventinal oil with low EROI-sources below 10:1 à la tight oil or tar sands at home …  So, just to project it over my thumb, I would say that if Dr. Campbell used let’s say a ratio of 30:1 for his calculation and if you try to keep the same work done using the "sweet spots" of unconventional sources aka with a net energy surplus 5 times smaller, you are at ca. 100 billion energy slaves. I think this calculation should be done on a per-country-basis to get a better picture, but it will still be only about oil.

Now if you compensate some losses in conventional AND unconventional production [think of the decline-rates an order of magnitude higher than in conventional fields] by trying to incorporate "renewables" that are not renewable, not new and require oil from A to Z, I think you will need additional hundreds of billions of slaves. But this would depend on your conventional/unconventinal-ratio and also on the type of substitutes used. On the other hand, "renewables" are no substitutes for liquid fuels anyway [except local methanol on a small scale perhaps], and I remember a blog-post by Dr. Tom Murphy about algae fuel, comparing its EROI with that from old newspapers being fished out of a pond, dried and burned.

So let’s take "renewables" again out of the equation and only keep liquid fuels from conventional and unconventional sources. If the minimum EROI required to fuel the most simple tasks in society is 3:1 [and I’m not talking about the military-industrial complex here with drones], and we had a ratio of 30:1 for our 22 billion slaves, this gives us a theoretical 220 billion "unconventional" slaves. All else being equal, if we consider that much over 90% of all transportation in the EU27 was based upon oil in 2006 … and will still be at about 90% for a certain time to come, I think 200 billion pure "unconventional" slaves would be the maximum upper limit."

So although Colin Campbell’s figure of 22 billion energy slaves looks safe when you consider decent EROEI conventional oil only, taking into consideration all of the other forms of fossilised life that we are currently extracting as fast as we can, we get much higher figures. Just to recap, these are the likely figures:

Daniel – 119 billion energy slaves
Gunnar – 120 – 600 billion energy slaves (average 360 BES)
Alex – 200 billion energy slaves

Taking an average of the above three results would give us a theoretical figure of 226 billion energy slaves.

What would 226 billion energy slaves look like? Humans occupy around only 2% of the surface of the planet, so assuming our energy slaves are distributed close to us rather than arrayed in horizon-filling ranks in the Gobi Desert or Antarctica, we can expect an energy slave population density as follows:

196,939,900 square miles – surface area of planet Earth
3,938,798 square miles – surface area of human populated areas
226,000,000,000 – number of fossil energy slaves in total (not including ‘nuclear slaves’ or ‘eco slaves’)
53,378 fossil slaves per square mile 

That’s an awful lot of invisible men running around in your neighbourhood! The only question remaining for me now is whether I should change the title of this blog …

PS. Tak to Daniel and Gunnar and danke to Alex – you’ll all be getting some Cornish fudge in the post.