Through the years one of the most significant indexes for measuring a nation's progress has been the per capita consumption of inanimate energy in the performance of work, the production of material goods, and the provision of services. Most of us have seen those charts that show the close parallel between the per capita consumption of energy and per capita income.

Much of the industrial and economic growth of the United States for almost 200 years has been based on an abundance of low-cost energy. However, recent events have brought increasing evidence that our fuel supplies, though they appear to be vast, are not adequate to support indefinitely an ever-increasing demand. Furthermore, environmental effects associated with their production and consumption are now a matter of major concern.