Question

Useful conversions: 1 BTU ~103 J; 1 kcal ~ 4 x 103 J; 1 food calorie = 1 kcal

1. The average US citizen uses 1 million BTUs per day as a member of our industrialized society. Assume this energy is provided entirely by a group of laborers, each capable of generating a steady 200 W of power (generous assumption) for an 8 hour shift. How many laborers does an average citizen require? Assume your laborers are 100% efficient at converting a 200 watt output into whatever form of power you require. State clearly any additional assumptions you make.

2. Assuming you pay your laborers the federal minimum wage of $7.25, what are your daily labor costs? For comparison, if you satisfy your energy needs entirely with coal, what would be the cost? (Last week, good quality, Central Appalachia coal futures were trading for about $80 per tonne.)

Answer 1