U.S. per capita energy usage
¥
100 quadrillion btu used each year
¥
= 10
20
joules = 100,000,000,000,000,000,000
¥
=
10
20
joules/year /(3x10
7
seconds/year)
¥
= 3x10
12
joules/second = Watts
¥
300 million people in the US = 3x10
8
¥
¥
Energy usage per person =
=
10 kW!