Energy backed currencies? Energy is in a constant state of flux from low to high-entropy states. And 50-100 years from now, energy will be the one thing that is

Energy backed currencies? Energy is in a constant state of flux from low to high-entropy states. And 50-100 years from now, energy will be the one thing that isn't in short supply, given that the sun sends more of it our way per year than we've used in human history: see http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf - page 10: 480 exajoules (EJ) strikes the Earth per 90 minutes. Convert that to the yearly number, and compare to worldwide energy consumption in the year 2001 of 430 EJ, bearing in mind that we didn't use much before the 19th century.