19/30325399 DC

This standard 19/30325399 DC BS ISO 50049. Calculation methods for energy efficiency and energy consumption variations at country, region and city levels: relation to energy savings and other factors is classified in these ICS categories:

• 27.010 Energy and heat transfer engineering in general

This document provides guidance on methods for analysing changes in energy intensity and energy consumption, and for measuring energy efficiency progress, for countries and regions. It is composed of three different calculation methods:

• Evaluation of structural effects in the variation of energy intensity;

• Calculation of energy efficiency indices;

• Decomposition analysis of energy consumption variation.

Energy intensity is often considered as indicator of energy efficiency at aggregate level when limited data are available. Their use as proxy for energy efficiency can be improved by removing from their variations changes in economic structures: this is the objective of the first part of this document.

With more detailed data on energy consumption available by sub-sectors or energy uses (e.g. space heating) or by modes of transport (e.g. cars), it is possible to assess energy efficiency trends through a more accurate indicator than energy intensity, called energy efficiency indices: this is the objective of the second method of calculation presented in this document.

The variation of energy consumption can be related to change in economic activity, to energy savings as well as to other explanatory factors: the purpose of the third method of calculation described in this document is to present the method of decomposition of changes in energy consumption. It makes use of the energy savings calculated according to the indicator based method, as described in ISO 17742.

This document considers all end-use sectors, such as households, industry, services (also known as tertiary sector), agriculture and transport. It does not generally incorporate the energy supply sectors, such as power plants, refineries or coal mines. However, the integration of the power sector can be considered in the decomposition of the primary energy consumption to account for the effect of variations in energy efficiency and energy mix in the power sector.

Energy consumption considered in this document excludes feedstock energy, such as oil products for the production of plastics or natural gas for the production of fertilisers, as they are not affected by energy efficiency policies.

This document is not intended to be used for calculating changes in the energy consumption or in energy efficiency at individual consumers’ level (e.g. households, organizations, companies) but rather to provide an aggregated statistical evaluation for a country, region or city.