- #1
mrblanco
- 5
- 0
I have a friend that wants to put several alternators on a car. However, he wants to gather the power from the wheels rather than the engine in order to "capture lost energy" and "save" fuel by running the AC and other electrical components off these alternators. I've already explained that this is not possible because the engine is driving the wheels, therefore, the source of energy is still the fuel in the car. Furthermore, getting the power from the wheels is less efficient than getting it from the engine as there are energy loses through the transmission and the driveline. Also, the new alternator(s) would decrease efficiency because it, itself is not 100% efficient and it would add to drag forces. He's really stuck on this idea, so I need to show him how it's wrong with the math. I am a bit stuck on this part. I know I need to do energy balance by using the first law of thermodynamics but that's as far as I'm getting.
I looked up the loses due to transmission and driveline and those are estimated to be around 5.6%. I also looked at several alternator efficiency curves and their efficiency is usually between 40% with peak efficiency going as high as 60%. I also looked up AC power draw and found it to be around 720 watts.
I haven't done a thermo or physics course in a long time so any help to get the ball rolling here would be much appreciated
I looked up the loses due to transmission and driveline and those are estimated to be around 5.6%. I also looked at several alternator efficiency curves and their efficiency is usually between 40% with peak efficiency going as high as 60%. I also looked up AC power draw and found it to be around 720 watts.
I haven't done a thermo or physics course in a long time so any help to get the ball rolling here would be much appreciated