Mr. Green Car: Carbon footprint of new cars—continued
Mr. Green Car
By Allen Penticoff
In the last episode of Mr. Green Car, we looked a bit at the carbon footprint of auto manufacturing and steel in particular. I made a comment about recycled steel perhaps having a carbon footprint nearly the same as virgin steel if one takes into account all the transportation involved with recycling steel. Don’t mistake this for not caring about recycling, or stating that it is not worth the bother. On the contrary, recycling of all materials is more important than ever.
The planet’s resources are limited, and to throw any of them away and not reuse them is simply foolish. As long as steel, aluminum, glass and plastics (to name a few) are reasonably economical to reprocess into new products, that should have priority over use of virgin materials. In reality, recycled materials are often blended with virgin materials to make a quality product that saves us from depleting resources.
Nearly all auto manufacturers design their products to be recycled to the fullest extent possible. A past Mr. Green Car investigated the auto recycling business.
It has been noted that the Toyota Prius has a higher manufacturing carbon footprint than many even larger vehicles. This is because the Prius, and similar hybrids, have more parts. The electric drive systems have more copper, steel and aluminum than does a vehicle without them. The battery packs require more mining and manufacturing to make them.
Another area where high-tech causes a greater carbon footprint is in the area of “exotic” materials. The steel industry claims its impact is much lower for a given strength than aluminum or carbon-fiber materials that make for the lightest components. These light-weight components do increase the fuel economy of a vehicle, but it may take a while before the increased efficiency makes up for the extra carbon dioxide and other gases released in their making. The steel industry is claiming that with new steel alloys and manufacturing technology, they can match the fancy stuff in strength and weight, and be greener in the end.
However, since the efficiency of a hybrid is so much higher than a non-hybrid, over the life of the vehicle, its carbon impact is lower. Besides that, with gas at $4 per gallon, wouldn’t you rather get 60 mpg than 30 mpg? That’s like getting gas for $2 per gallon.
Some anti-hybrid folks have been implying that the mining of lithium is a precious commodity that is in limited supply in few locations. While it is true that lithium is mined or processed (from sea water, for example) in only a few places, my research has shown it is a very common element on this planet, and the supply is bountiful. The cost arises in the process of making these high-energy lithium-ion batteries. You probably have one in your cell phone or camera now. They tolerate high charge and discharge rates, and don’t have a “memory” to speak of—but when they do get to the end of their life, they can give out rather suddenly. This brings up the next issue.
An issue that has begun to rear its head is expired lithium-ion battery packs in hybrids. Caution unto you who seek an older Prius for a very cheap price. Its battery pack may be nearing the end of its life. I have been advised that a Prius will not operate without a viable battery pack. I wish I had a quoted price to give you at the moment—I was told it was about $3,000 to replace one. Now, if this is taken into account during the purchase, and you are going in with eyes wide open, then you may still be able to go hybrid and save some money and save on building a new car. Most Priuses I’ve seen are driven quite gently, so I’d expect the engine to last, especially if the synthetic oil were changed at the recommended intervals. If you have the need to replace a battery pack, the dealer will be sending off the old one to be recycled. This is not a do-it-yourself job.
I guess we did not look at “carbon footprint” numbers here again. But I hope to have stirred your thinking—that there is much hidden in the world that affects us all. Many things we don’t consider at all, but they are there nonetheless.
From the April 20-26, 2011 issue
Print This Article