Throughout the 20th century, the yearly consumption of electricity in the US increased exponentially at a continuous rate of 7% per year. Assume this trend continues and that the electrical energy consumed in 1900 was 1.4 million megawatt-hours.

Question

Find the average yearly electrical consumption throughout the 20th century.

Answer 1

after n years,

energy = e(n) = 1.4*10^6 * 1.07^n

e(100) = 1213.8*10^6

(1213.8 - 1.4)*10^6/100 = 1212.4*10^4 = 12.124 megawatt-hr/year