My friend and OneWorld colleague, Peter Armstrong, never does anything by halves. About two years ago he decided that he wanted to reduce his family’s carbon footprint (which was high because he and his partner Anuradha have to do a lot of air-travel). He started with their house in Oxfordshire and installed a heat-pump as well as doing a lot of insulation etc. He also blogged the entire process in a fascinatingly open way. Here is his assessment of where they’ve got to after the first year of the new regime.

October marked the end of the first year with the heat pump and the other energy saving measures we have put in place. The results are very interesting and to some extent surprising. We can look at them in a number of different ways.

Our baseline was 2004 when our heating oil cost £2,431 and our electricity £2,292, giving a total energy cost for the house of £4,732.

Now in 2006 (Oct 2005-Oct 2006) we have only electricity to consider. This breaks down as non-heat pump £1,481 and heat pump £1,663, giving a total energy cost of £3,144.

So we may conclude that we have a crude saving of £1,579 on the year, about half from using less general electricity and half from using the heat pump instead of oil.

Perhaps more interestingly, the cost of oil in 2006 would have been £3,403, which would have made us another £1,000 worse off.

So we could say that the heat pump (cost £13,000) will pay for itself in seven years at 2006 oil prices…