Abstract
Throughout mankinds history, energy consumption has changed substantially due to the growth of the worlds population and the great changes in human activities. The worlds population continues to increase, having nearly doubled during the past third of this century. World energy consumption has increased even more rapidly, having more than quadrupled over the same period. The observation of historical consumption data over a significant time period clearly indicates that there are no reasons to expect an interruption of this qrowth in the future which is considered to be the most important stage in the history of energy consumption. Each level of energy consumption has been accompanied by the corresponding primary energy sources and by the energy-related technological development. The development of energy systems will be determined in the near future by contemporary energy technologies based on the exploitation of traditional energy resources, but in the more distant future technologies based on the exploitation of thermonuclear and solar energy will play the decisive role. Future energy development will be determined to a great extent by social and ecological factors and by the publics acceptance of new energy technologies.