Not all unexpected paradoxes are true
A report by an American car marketing consultancy claiming that, including manufacture and disposal, a Hummer uses less energy than a Prius, has received some attention in the press recently. The report interested me, because product lifecycle analyses are quite rare (in an earlier post, In Balance noted that carbon footprint analyses almost always exclude capital activities).
Plus, life-cycle analysis does sometimes turn up unexpected results. According to Lincoln University, raising lamb in New Zealand and shipping it to the UK produces less that a quarter of the greenhouse gases of raising and consuming lamb in the UK. Or, according to the University of Edinburgh, manufacturing and buring maize and rapeseed biofuel leads to higher greenhouse gas emissions than fossil fuels.
So I had a look at the Hummer v Prius report, Dust to Dust (pdf), which was published by CNW Marketing Research in March 2007. I couldn’t unravel the methodology, except that it is written on a white board in CNW’s office, or find any data in the 458 pages.
I (and most other people) suspect that the Hummer v Prius claim is wrong. In most studies, fuel consumption is between 70% and 90% of a car’s lifecycle energy use (e.g. sustainability report from the UK’s car trade association – pdf). Unless the Prius and/or Hummer vary radically from this, the Prius could not have higher lifecycle energy given it has twice the fuel efficiency.
Anyway, the point is, CNW is right about one thing: there are hidden energy costs in all products. Lots of high value products, including white goods, cars and now new build houses, have efficiency labels that look at the energy required to run the products. These labels should also include an indication of the energy required for manufacture and disposal.