Our modern societies are highly dependent on energy, especially fossil fuels, for most aspects of our lives (agriculture, medicine, etc.), including transport for moving people and goods. However, the supply of energy can be disrupted by several factors: natural resources shortage, imposition of higher energy prices due to action by OPEC or any other cartel, war, political and economic disputes, or physical damage to the energy infrastructure due to terrorism or natural disasters. Energy independency relates to the goal of reducing the imports of the different sources of energy (oil, coal, uranium, etc.) in order to reduce the uncertainties regarding energy prices or shortage.

The dependency of the European Union (EU) on energy imports, particularly of oil and more recently of gas, forms the backdrop for policy concerns relating to the security of energy supplies. The EU’s increasing dependency on energy imports from non-member countries results from the shortfall between production of primary energy sources and energy consumption. More than half (54.1%) of the EU-27’s gross inland energy consumption in 2010 came from imported sources (Eurostat, 2011).

The energy shortage has direct impacts on the energy costs. However, the future path of energy prices is hard to predict. An energy shortage also entails risks of transport service disruption, as you cannot run a tram or a metro without power.