Annual electricity use by the typical household that uses mains gas for its heating isabout 3700kWh, or ‘units’ in conventional usage. Deducting approximately750kWh/year for lighting leaves about 2950kWh/year for other appliances, or about 1.4 tonnes of carbon dioxide. This figure is rising slowly here as well as in other countries. In The Netherlands, for example, electricity use in the home rose by 2.8 per cent a year in the period 1995 to 2002 compared to about 1.7 per cent in the UK.145, 146
The estimates in Table 9.1 of the cost per tonne of carbon dioxide saved assume that the house has an existing appliance of typical household efficiency, bought eight or so years ago. It compares the electrical consumption of the best new appliance with this figure. This produces a cost per tonne of carbon dioxide saved, and the numbers are all high. For people who have already decided to buy a new machine, the figures will be lower because, in these cases, it would be more appropriate to calculate the incremental cost of the best new machine over a typical model in the shops today. These figures are given in the text.