Technical efficiency of economic systems of EU-15 countries based on energy consumption

► Technical efficiency index of EU-15 countries is determined through the DEA method. ► Level of the TE index is determined from the energy mix used in each country. ► TE level depends on the maximization level of GDP without waste of energy resources. ► Capacity of an economy to produce more GDP for a given energy input is determined. ► TE differentiation before and after the integration of nuclear energy is performed.