The energy system

The world energy system is so huge that it is challenging to modify it. Energy is vital for our life and for our economy. Therefore, the world energy demand is increasing for the growing population and the quality of life improvements. Therefore, energy remains the fundaments of nations strategy. Any Manichaean attitude toward any energy could not be a solution, all primary energies have a role to play. The reserves and geopolitical consequences of conventional and non-conventional energy will be analysed. The limitation of intermittent renewable energy use will be presented; this will justify why so many countries are relying more and more on conventional energies. In chapter 3 we will review the 3 final uses of energy: electricity, heating and cooling and transportation. Energy efficiency is not an energy but its potential but also its limitations will be presented. All this will allow analysing the potential and timing of the energy transition system and conclude that a systemic approach of energy is compelling to understand and act wisely in energy policy.