Productivity of Energy: Engineering and Economic Factors

A simple and practical graphical method for making international or interregional comparisons of energy productivity has been developed and applied to some specific significant cases. The method is based on definitions of national energy productivity as gross domestic product (GDP) per unit of energy consumed, annual per capita energy consumption, and the product of these two numbers which is GDP per capita. In order to facilitate realistic assessment of comparisons of unlike economics, two indexes are defined for individual products and energy forms. The product value index is defined as the value of product (e.g., steel or cotton) per unit of energy consumed in production. The cost of fuel index is defined as the cost to the user per unit of energy content in fuels. Application of the method, using United Nations statistical data, shows that variations of about 2 to 1 in energy productivity are essentially uncorrelated to much larger variations of over 50 to 1 in annual per capita energy consumption.