A friend of mine came to me with a “patentable invention.” He said it was going to make him millions but he needed just a little help with the last bit.
He had glued a small electric motor on the end of a board, pointing outward. On the shaft of the motor was a bar magnet. The kind you could buy in the five and dime (when there were such things as 5&10 cent stores). Glued next to that motor was another motor with yet another bar magnet positioned ever so closely such that the magnets would not touch. He had actually placed six motors equally configured along the board. He could spin the first motor and the others, like little ducklings, would follow along. He put a lot of work into this project. He was very proud of it.
He understood that a motor could be used as a generator but couldn’t figure out how to get that generated power to work for him. I, being his electrical engineer friend, could help him out. Or so he thought. His idea was that he could start the first motor, and that the subsequent motors would spin generating five times the energy as there were five other motors. He could use one motor to power the first with four times the energy to spare for other things.
It was a really neat idea. Somehow, in his mind, the magnetic transmission made it all possible. Did I tell you he was very proud of his work? I felt so bad trying to explain the conservation of energy to him.
The desire to invent a perpetual motion system has always been in the minds of inventors since the beginning of time. With the impending doom of running out of oil sometime in the foreseeable future, the hope of coming up with something that at least approaches perpetual motion increases. In the automotive world this hope manifests itself in the form of hybrid electric vehicles.
The hybrid mystique
Sure enough, we are starting to see more hybrid electric vehicles on the road. The ones that are really noticeable are the ultra small, odd looking things that advertise by their overall appearance. Their owners drive with pride knowing that they are saving the environment by driving their cars.
Unfortunately, another extreme is sharing the same space with these gas sippers—the Sub-Urban assault Vehicle (SUV). These behemoths, with their drivers busily talking or texting, or staring at their GPS, could easily consume one of those little fellas and not even belch.
Then there is the SUV hybrid electric vehicle, which seems to be a bit of an oxymoron to me. You take a 15-miles-per-gallon vehicle, add $10,000+, and get a huge battery pack and an electric motor with a fairly complex dual mode transmission. With all of that you get 21 miles per gallon in the city, but the highway mileage doesn’t change. Funny thing is, these people think that they are saving the environment. They are not even saving money.
That added 6 mpg in the city costs the consumer over ten grand. You can buy a lot of gas for ten grand. At ten thousand dollars the proud owner of one of these vehicles would have to drive for 175,000 miles in the city just to break even at $3 per gallon. That’s a lot of city driving.
If we exclude plug-in hybrids, a hybrid vehicle uses gasoline to charge the batteries. So 100% of the energy used comes from the gas tank. The difference is that the conversion of that energy is done first by the internal combustion engine (ICE) and then by the electric motors and supporting control circuitry instead of the ICE alone. Let me repeat, all of the energy used to push the car forward came initially from the gas tank. That means that the energy in the hydrocarbons had to pass through the gasoline engine before it ended up as electron flow in the electric motors.
As my poor friend had to realize, energy cannot be created. It can only be transformed. When you add steps to the process of energy transformation (liquid gasoline to forward motion) you add loss. One cannot add steps without adding loss. So the question is, how do these hybrids actually give us better gas mileage? They do it by optimizing the least efficient element in the system, the internal combustion engine. They also do it by reducing your expectations (read, horsepower).