By Lorrin Windahl.

I work in an office of about 90% guys. This means that every lunchtime the topic of conversation is cars, cars and just a little more on cars. As I have about as much interest in cars, as I do in the nocturnal habits of blowflies, I generally tune out of these conversations.

Toyota Prius.

A little while ago though, my interest was piqued when I heard their discussion about electric vehicles. Well, hybrid cars to be exact. One argument I heard was that it took more energy to make a Toyota Prius than it did a Hummerso how sustainable could it really be. I thought today I might look a little more into this.

It turns out that it is true that it takes more energy, when you factor in waste, to produce a Toyota Prius than a Hummer. This was first documented in a 2007 report commissioned by the auto industry. Toyota even admits this. Although the car is manufactured in much the same way as a conventional petrol car,  the additional electric motor and battery pack does have an impact.

The Hummer takes less energy to produce but this is negated by its petrol guzzling and greenhouse emissions during use.

In my opinion though, I think the argument about the Prius and Hummer is somewhat misguided when analysing the sustainable integrity of the Toyota Prius. I have always been under the impression, that in order to reduce the carbon footprint of a product you first analyse the lifecycle of the product. Then you can identify where the product has the largest impact. I would think that with cars it is the use stage. Not, the manufacturing stage. And according to an article by Dave Roos this is indeed correct. In his article, Roos makes mention to a study, by Burnham et al,  that compared energy and emission effects between a conventional car and a hybrid. The results suggest that the higher energy demands and greenhouse gas emissions of the conventional car outweigh any imbalance between the two during production.

So, even though the argument about the Prius and Hummer is true, I still think that it is a more sustainable option. The great shame though, is that we are still using fossil fuels to generate electricity to power these vehicles.