ABSTRACT
Global energy consumption in the last half century has increased very rapidly and is expected to continue
to grow over the next 50 years. However, we expect to see significant differences between the last 50 years
and the next. The past increase was stimulated by relatively “cheap” fossil fuels and increased rates of
industrialization in North America, Europe, and Japan; yet while energy consumption in these countries
continues to increase, additional factors are making the picture for the next 50 years more complex.
These additional complicating factors include the very rapid increase in energy use in China and India
(countries representing about a third of the world’s population); the expected depletion of oil resources
in the not-too-distant future; and the effect of human activities on global climate change. On the positive
side, the renewable energy (RE) technologies of wind, biofuels, solar thermal, and photovoltaics (PV) are
finally showing maturity and the ultimate promise of cost competitiveness.
