Security of energy supply, the second wing of the common energy policy, is defined as the ability to ensure the continued satisfaction of essential energy needs by means of, on the one hand, sufficient internal resources exploited under acceptable economic conditions and, on the other, of accessible, stable and diversified external sources. With this definition, most European countries had a more secure energy supply in the 1950s than they had in the 1970s or even in the 1990s, despite their efforts in those three decades. Indeed, at the beginning of the 1950s, the Community's energy economy revolved around indigenous resources, chiefly coal. In 1955, coal met 64% of gross internal energy consumption in the then Community of Six; but little by little, demand switched from primary energy to processed energy, chiefly electricity and petroleum products. Due to strong growth in demand for light petroleum products (chiefly petrol), heavy fuels became residual products, which refiners wanted to get rid of at any price, often below that of crude oil. Unfortunately for coal, its main competitors were these heavy, industrial use fuels. In that oil was almost exclusively imported from third countries, the consequences on the Community's energy independence were plain to see. Energy independence was sacrificed on the altar of rapid industrial growth, stimulated by low energy prices.
The crisis at the end of 1973 brutally highlighted the Community's energy problem and the soaring prices resulting from it aggravated the situation. The problem was structural and not simply short term. By 1973, in fact, the Community was 63% dependent on third countries for energy supplies. The energy crisis clearly illustrated the extent to which the economies of the Community countries and even their political decision-making independence could be jeopardised by a group of countries that held in their grip the bulk of energy supply. The new energy policy emphasises the importance of measures which ensure solidarity between Member States and of the diversification of supply sources and transportation routes. Minimising the vulnerability concerning imports, shortfalls in supply, possible energy crises and uncertainty with respect to future supply is nowadays a first priority for the EU.
Security of supply is closely bound up with energy demand. Steadily growing demand constitutes a major risk where the security of energy supply is concerned. Following a Commission Green Paper, entitled "Towards a European strategy for the security of energy supply" [COM/2000/769], a consensus has emerged around some key issues, such as the need to considerably improve energy efficiency, to step up the promotion of renewables, to reduce environmental damage from energy use, to improve the investment climate in supplier and transit countries, and to develop the producer-consumer dialogue [COM/2002/321].