Lies, damn lies, but where do they get those statistics?
I was at an event the other week where a keynote speaker put up a picture of an ancient Landrover and said “This is my car. I’m eco-friendly as the emissions from vehicle production are much higher than those in use, so keeping it on the road is the right thing to do!”
“Rubbish” thought I (or words to that effect). But I gave him the benefit of the doubt and looked up some published stats, and as you can see the use phase comes to 80% and the manufacture 18%.
Fuel production 8%
Vehicle production 6%
Material production 12%
But everybody knows this – who on earth told him the opposite?
In May’s ENDS Report, a Rosi Fieldson is quoted as saying “The more technologies that are put into a home, the higher the embodied carbon [ie that required to produce materials, components and build the house] becomes. Currently embodied energy is 15% of energy used over the building’s life time …. In a zero carbon home this would rise to 80-90%.”
Well either Dr Fieldson has been misquoted or she needs to go back to primary school to sort out her maths. It’s a percentage! If you cut one part of the pie, the percentage taken by the other must go up because the two parts must add up to 100!
Strictly speaking the embodied energy of a zero carbon home should be 100% of lifetime energy, because the usage (non-renewable) energy is 0%. But it doesn’t tell you whether the amount of embodied energy goes up or down…
I think I’m going to go and lie down in a darkened room…