Minimum per capita energy requirement of man is about 2000 kcals. Which is the quantity required to keep him alive and is obtained from food he eats. In a primitive society, apart from cooking, lighting, heating etc. there was little need of more energy. Industrial Revolution has, however, brought in an era of concentrated use of large amounts of energy.
Per capita energy consumption, which was a little more than 2000 kcals, has now shot up to about 100 times in technologically advanced countries of the world. There has been a rapid and steady rise in global energy consumption ever since the fossil fuels came into wide spread use. We have entered an Age of rapid consumption of fossil fuels, which represents the photosynthesis of millions of years ago.
Per capita consumption of energy is not the same all over the world. It is highest in advanced; Western countries. Only 20% of the world’s people consume about two-third of the total energy produced by man while the rest of the population has to live with only one-third of the energy supply. To millions of people living in developing countries of the world electricity is still a dream, fossil fuels are difficult and costly to obtain and biomass constitutes the only source of energy.