Under the 2008 Climate Change Act, the UK is committed to reduce greenhouse gas emissions to 66% of 1990 levels in 2020 and then to 20% in 2050. These medium and long-term targets imply a reduction of about 3% year on year.
Emissions from energy use in the home make a significant contribution to the UK’s total – a figure of 27% is widely used. By 2005 home-energy related emissions had increased 6.3 per cent from 1990 but the trend since 2005 has been downwards.
With gas and electricity meter readings being collated centrally, it’s fairly straightforward to work out if we are reducing our use of energy at home, and if we are doing it in line with the 3% annual reduction needed to support the long term overall target.
For the years 2005 to 2007, the answer for Great Britain is that we definitely are – by some margin. However the South East region is failing.
The figures here are for domestic energy use, per household, so they take into account changes in the numbers of dwellings.
|Domestic GAS||2007 vs 2005||2007 kWh|
|Domestic ELECTRICITY||2007 vs 2005||2007 kWh|
(These figures of course exclude any use of wood and oil for home heating. They also exclude Northern Ireland)
What strikes me as significant?
Across all the councils I’ve selected here and across Great Britain, our use of gas has reduced faster than our use of electricity. Have milder winters reduced our need for heating and magnified the effect of better home insulation and more efficient heating systems? Or has electricity use dropped less because the positive effects of low energy lighting, energy efficient applicances for example, are being offset by increased use of electronics in the home – more TVs, games consoles, computers, and bigger screens, all being left on for longer?
Woking achieved a creditable reduction of 5.9% in gas usage but electricity consumption only fell by 1.1%.
In the South East, gas use per household in 2007 was 17799 kWh, just 1% above the average for Great Britain. Warmer weather overall in the South East should mean we need less heating than the rest of the UK. I suspect our bigger houses and aversion to sweaters cancels that out.
Whereas South East domestic electricity at 4741kWh per household, was 7% higher than Britain’s.
In affluent Surrey, the picture is gloomy. Woking’s houses used an average of 19641 kWh of gas and 5025 kWh of electricity in 2007 – 10% and 6%respectively worse than the South East.
But on a positive note, cutting household energy use in Woking by (say) 10% will have a bigger effect on the country’s emissions than the same percentage reduction in an area with lower energy use.
The carbon intensity of gas and electricity are markedly different. Currently electricity has a carbon intensity of about 0.43kg per unit (1kWh), and gas is 0.19. For the average Woking house, the total annual energy-related emissions are therefore 2.16 tonnes from electricity and 3.79 tonnes from gas. Over time, the electricity grid will be de-carbonised as wind power comes on line and coal power stations are closed. As a result, the proportion of household emissions due to gas usage will tend to increase.
Spreadsheets giving gas and electricity usage data for all council areas in Great Britain are available for downloading from DECC.