Robert U. Ayres
Emeritus Professor of Economics and Political Science and Technology Management
Useful Work; Efficiency; Energy Intensity; Decomposition; European Competitiveness; Europe
Energy intensity measures, defined as the ratio of energy use to gross domestic product of a country, are widely used to study the productivity of energy use in an economy.Unlike conventional primary and/or final energy intensities, useful work intensity (useful work/gross domestic product) addresses the problem of aggregating in a single measure the different energy forms used, and allows for a clear distinction between thermodynamic efficiencies and structural changes in the demand for energy end-uses.Here, the aim is twofold: (1) Disclose the factors that control the useful work intensities across the EU-15 countries over the deindustrialization process, performing a decomposition of the useful work intensities from 1960 to 2009. (2) Describe a methodology for the automatization of useful work accounting, based on a general mapping of energy end-uses from IEA (International Energy Agency) energy balances.The authors show that, in contrast to the other conventional energy intensity measures, useful work intensity depends only on the intensity of high temperature heat uses and the relative size of residential energy needs.Aggregate thermodynamic efficiencies slightly increased as a consequence of technological improvements, but were negatively affected by deindustrialization, as a consequence of a transition to less efficient and productive energy uses.