Welcome to my rants page! You can contact me by e-mail: bob@goodsells.net. Blog roll. Site feed.

## Thursday, August 04, 2005

### Correction

[Technical warning: This is an esoteric, calculation-filled review of an esoteric book.]

Last week, I quoted from a review of the book Oil Addiction: The World in Peril by Pierre Chomat. Here is a part of the review that I quoted:
One gram of oil gives as much energy as a manual labourer can deliver in a day’s work. He quotes some nice examples: a plane load of tourists, flying from California to see the Great Pyramid of Egypt, consume as much energy as was used in building it. Running a domestic clothes-washer consumes as much energy as it would take a crane to lift the house 23 feet into the air.
I bought the book, and started reading it. It quickly became clear to me that there were serious flaws in Chomat's calculations, particularly the first one, which I'm afraid he used as the basis for making many other mistakes throughout the book. By my calculations, one gram of oil contains approximately 12 watt-hours of energy, something a normal person could easily generate in five or ten minutes of moderate exercise. Chomat did his calculations in calories, and seems to have forgotten that a food calorie (which is also the calorie you see on exercise machine readouts) is equal to 1000 physics-type calories (heat needed to raise 1 ml of water 1 degree C). So most of his calculations seem to be off by a factor of 1000, making oil seem to be a far more potent energy source than it really is (which is still quite potent).

If you're interested in double-checking me, here is what Chomat says:
The thermal energy available in one drop of oil, weighing just one gram, is approximately 10,000 calories, or 10 kilocalories. This is equivalent to the amount of work a laborer can accomplish during a full work day.