Here we go.
|My understanding of what you are saying is that the alternator is spinning, and thus generating electricity, regardless of whether any of that juice is actually being used. This is not the case. With no load, the alternator is simply freewheeling. Once a load is placed on the alternator, it becomes harder to turn, and the engine must do more work (and consume more gas) to make it do so. You have experienced this yourself if you have ever used an exercise bike such as a LifeCycle. These bikes drive a generator that operates the internal electronics. When you increase the level, additional load is placed on the generator and the pedals become harder to turn. Same deal in a car.
taken from http://www.straightdope.com/columns/...ur-gas-mileage
When anything is running on your alternator - stereo, heating, air con, etc.. The alternator adjusts it's load depending on how much power is required.
Ever heard the story about how the air con reduces the power on your engine? Well thats why.
Any method that cools down the engine air intake directly from the alternator power will draw more power from the engine than it puts in
because the system is not 100% efficient. This is part of the 2nd law of thermodynamics which basically says you cant get out more than you put in.
You can see that if it was the other way around, and that the TEC allowed the engine to generate more extra
power than it took to originally run the TEC then you would have an impossible system that would be generating more energy than you put in.
This works for the case of your engine, or something so large as a power station.