Friday, March 10, 2006

Interesting ideas on energy

The Energizer - Discover Magazine - science news articles online technology magazine articles The Energizer

The above article is in the Discover magazine that is currently being sold in newsagents in Australia.

It sets out some of the ideas of Amory Lovins, who I can't recall having heard of before. Some of his ideas on saving energy make quite a bit of sense, and this section on cars is interesting:


A modern car, after 120 years of devoted engineering effort since Gottlieb Daimler built the first gasoline-powered vehicle, uses less than 1 percent of its fuel to move the driver. How does that happen?

Well, only an eighth of the fuel energy reaches the wheels. The rest of it is lost in the engine, drivetrain, and accessories, or wasted while the car is idling. Of the one-eighth that reaches the wheels, over half heats the tires on the road or the air that the car pushes aside. So only 6 percent of the original fuel energy accelerates the car. But remember, about 95 percent of the mass being accelerated is the car—not the driver. Hence, less than 1 percent of the fuel energy moves the driver. This is not very gratifying.

Well, the solution is equally inherent in the basic physics I just described. Three-quarters of the fuel usage is caused by the car's weight. Every unit of energy you save at the wheels by making the car a lot lighter will save an additional seven units of fuel that you don't need to waste getting it to the wheels.

So you can get this roughly eightfold leverage (three- to fourfold in the case of a hybrid) from the wheels back to the fuel tank by starting with the physics of the car, making it lighter and with lower drag. And indeed you can make the car radically lighter. We've figured out a cost-effective way to do that so you can end up with a 66-mile-per-gallon uncompromised SUV that has half the normal weight, has a third the normal fuel use, is safer, and repays the extra cost that comes with being a hybrid in less than two years.

His idea is to makes cars mostly from carbon fibre. He points out that super light cars also make use of hydrogen as a fuel more attractive too.

His ideas on electricity generation are less radical, emphasising conservation a lot. He also likes wind power, about which I remain somewhat of a skeptic. Still, he ideas sound well worth taking seriously.

No comments: