Energy is vital for all types of activities on earth whether living or non-living. This paper first discusses some misconceptions about energy and energy sources. A new classification of energy sources, contrary to traditional renewable and non-renewable sources, is then presented. The energy sources are classified as sun-dependent energy sources (SDES) and sun-independent energy sources (SIES). Total energy use of the world, today and in the long future, and a possible energy scenario is proposed in the light of this new classification of energy sources. Unlike previous energy scenarios which cover few decades to a maximum of few centuries, this paper presents the energy use and policy guidelines for long into the future keeping in view the energy sources available at that time, their optimum utilization, total world population and energy-use-per-person constraints.
