Figures for the effect on energy consumption within the UK by energy-saving measures for this particular period are not readily available. However, for the climate change programme review, we prepared estimates of the effects on carbon emissions for the household sector in the 1990s and separately for the present decade.
The Government estimate that energy efficiency improvements in the household sector in the 1990s would have contributed around 4.5 million tonnes of carbon (MtC) of emissions reductions, that is, some 12 per cent. of 1990 emissions. At the same time, growth in demand for underlying energy services—warmer homes, hot water—would have increased emissions by 11.5 MtC; the increase in the use of gas for generating electricity instead of coal in the 1990s, which reduced emissions from power stations, and so reduced the associated emissions from electricity use in homes, businesses, etc, would have decreased emissions by 8 MtC; and smaller factors, mainly fuel switching by householders and changes to external temperatures, would have contributed a further 1 MtC of reductions. The overall effect on emissions was a net reduction of around 2.5 MtC.
In the present decade, before the effects of policies are included, we estimate that background energy efficiency would save a further 4.5 MtC. Increasing demand for energy services, together with the effects of the other factors described earlier, means that the net overall reduction in this period would be approximately 0.3 MtC.
The estimated effect of all the energy efficiency policies for households set out in the new UK climate change programme 2006, is an additional reduction of 4.8 MtC by 2010. Most of these savings are expected to be delivered between 2005 and 2010, through tighter building regulations and further activity under the energy efficiency commitment.
Data are not available to conduct similar analyses for the industry and service sectors, but the contribution of energy efficiency is expected to be similar in percentage terms.