Access to cheap energy has become essential to the functioning of modern economies. However, the uneven distribution of energy supplies among countries and the critical need for energy has led to significant vulnerabilities. Threats to global energy security include the political instability of several energy producing countries, the manipulation of energy supplies, the competition over energy sources, attacks on supply infrastructure, as well as accidents and natural disasters. It is also the limited supplies of the most common forms of primary energy, i.e. Oil and Gas that changes perceptions on this topic. Although plenty of coal, up to 155 years worth, is readily available, coal is not the fossil fuel of choice for many more advanced countries because of its highly polluting nature. The potential need to change our primary energy sources in the foreseeable future is the crux of the energy security question, leading to higher prices, more limited access to sources of energy, competitions and political troubles, which in turn make the threat even larger.