(c) Limitations of the Indicator: The aggregate indicator for the industrial sector
reflects both the energy intensity of various branches of manufacturing and the
composition of the manufacturing sector. Changes in the aggregate indicator can
therefore be due either to changes in energy intensity or to changes in relative branch
output (structure). Similarly, differences between countries may be due either to
differences in energy efficiency or to differences in the structure of the manufacturing
sector. A country with large energy-intensive industries, such as pulping, primary
metals or fertilizers, for example, will have a high energy intensity, even if the
industry is energy efficient. For this reason, it is desirable to disaggregate energy
intensity by manufacturing branch and by industry.
Intensities measured as energy per value added at a disaggregated level are affected
by changes in the structure within each branch — for example, by changes in the mix
of metals produced within the non-ferrous metals sector or in the share of pulp versus
paper in total paper and pulp value added. While desirable, detailed calculations, such
as total energy use for particular products using input-output tables, are very data
intensive and difficult to update regularly.
(d) Alternative Definitions/Indicators: Energy use per unit of physical output in
industries. For some purposes, physical output would be preferable, but this is not
possible using the energy-use statistics available in many countries, and there are
many sectors for which aggregate physical output cannot be easily defined.
ASSESSMENT OF DATA
(a) Data Needed to Compile the Indicator: Energy and electricity use by industrial
sector, by manufacturing branch and by selected industries; value added or gross
output.
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