Well, I just came across this article:

http://www.informationclearinghouse.inf ... e11213.htm

which sources back to:

http://www.lifeaftertheoilcrash.net/Res ... #anchor_71

1. How Much Human Energy Is Contained in One

Gallon of Gas?

From Dr. David Pimentel:

"That is, the 38,000 kcal in one gallon of gasoline can be transformed into 8.8 KWh, which is about 3 weeks of human work equivalent.(Human work output in agriculture = 0.1 HP, or 0.074 KW, times 120 hours.)"

He, of course, is accounting for the energy lost in the process of converting the gasoline into usable energy.

My calculations excluding the energy lost in the conversion process are as follows:

1 Gallon of Gas = 125,000 BTUs

Source: US Department of Energy

3,400 BTUs = 1 KWH

Source: US Department of Energy, Bonneville Power Mgt.

1 Gallon of Gas = 37 KWH

(125,000 BTUs in a gallon of gas divided by 3,400 BTUs in 1 KWH)

1 Gallon of Gas = 500 hours of human work output

(37 KWH in 1 gallon of gas divided by human work output in agriculture of .074 KW = 500)

2. How Much Human Energy Is Contained in One

Barrel of Oil?

1 Barrel of Oil = 5,800,000 BTUs

Source: Louisiana Oil and Gas Association

1 Gallon of Gas = 125,000 BTUs

Source: US Department of Energy

1 Barrel of Oil thus contains the energy contained in 46.4 gallons of gas

(5,800,000 divided by 125,000 = 46.4 )

1 Gallon of Gas = 500 hours of human work output

Source: Calculations Done Above.

1 Barrel of Oil = 23,200 Hours of Human Work Output

(Energy equivalent of 46.4 gallons of gas per barrel of oil x 500 hours of human work ouput per gallon of gas = 23,200 hours)

If you assume about 21 million barrels per day for the US, that's roughly 21million/300million = 0.071 barrels per day per person.

0.071 * 23,200 = 1647 man-hours per day per person.

Assuming 12 hour workdays: 1647/12=137 slaves per person.

It makes the "return to feudalism" scenario painted by S.M. Stirling in "Dies the Fire" all that much more plausible:

"There are only two ways to live now; farming, and running the farmers."