LITERATURE REVIEW

Harry C. Wilting et al. studied the energy intensity trends for 56 Dutch economic sectors for a period of20 years (1969-1988).⁵ The intensities were calculated by using input-output analysis. Energy intensities have error margins due to uncertainties in the parameters of the input-output model. Uncertainties in energy intensities for any year are less than 8 percent for most sectors. The effects of energy price changes were examined. More than half of the economic sectors show significant declines in energy intensities as a result of increasing energy prices. The results estimate that there was an 18-percent decrease in the ratio of domestic primary energy use and the GDP (energy intensities) for the period 1973-1987. Energy intensities decreased in 40 of the 56 sectors; in 30 of these sectors, the decrease was greater than 10 percent.

Kees Vringer and Kornielis Blok analyzed the changes in energy consumption patterns of Dutch households for a period of 48 years (1948 to 1996) in order to discover whether these changes have influenced the energy intensity of the society.⁶ Due to the rise in consumption, the total household energy requirement per capita grew an average of 2.4 percent annually over the 48 years. In the same period, the total energy intensity of households fluctuated but on average changed from 5.6 to 6.3 megajoules/1995 Dutch guilder (MJ/NLG), an increase of 0.25 percent per year. By excluding the direct energy consumption, there is a slight decline in the indirect energy intensity, from 3.8 to 3.6 MJ/NLG (-0.14 percent per year). No significant trends to lower energy intensity are found, and there is no indication of dematerialization of the consumption patterns.⁷

T. V. Ramachandra et al. have studied the energy prospects in the industrial sector for Karnataka state in India.B In the industrial sector, energy per state domestic product is 10 to 20 times higher compared to that of the industrialized countries. This implies inefficiency in energy utilization. Detailed investigation of the industrial sector, through analysis of specific (industry and sector) energy consumption for a period of seven years reveals that about 28 percent of energy could be saved in the industrial sector, which amounts to 2.25 million toe of energy or 1,541 million kilowatt-hours (kWh) of electrical energy per year in Karnataka. This savings is equivalent to the energy output of a 300-megawatt (MW) electric power-generating unit (hydro/thermal)⁹

Zhong Xiang Zhang studied the changes in energy consumption in China's industrial sector in the 1990s, based on the data sets of value added and end-use energy consumption for the 29 industrial sub sectors using the newly proposed decomposition method of giving no residue.¹⁰ Results show that 88 percent of the cumulative energy savings in the industrial sector for the period 1990-1997 was attributed to real intensity change, with approximately 80 percent of such savings from the four main energy-using subsectors. The contributor to the decline in industrial energy use in the 1990s was the decline in energy intensity. The trend of energy-intensity decline that took place during the 1980s (at the double-digit level) was maintained during the 1990s.¹¹

Fridtjof Unander et al. examined residential energy use in the Scandinavian countries (Denmark, Norway, and Sweden) for a period of 26 years (1973-1999).¹² They employed a decomposition approach to investigate the differences in the residential energy demand structure and end-use intensities. The results show that, in contrast to Denmark and Sweden, Norway saw a growth in total residential energy use between 1973 and 1999. But the analysis also indicates that Denmark and Sweden achieved significant reductions of residential energy intensities between 1973 and 1990, while the reductions in Norway were negligible. After 1990, however, there was a strong decline in residential energy intensities in Norway and a high rate of energy savings compared to most other countries, while energy savings in Denmark and Sweden almost halted.¹³