Hard Numbers on Electric vs. Fan Clutch

I am considering switching out my stock fan clutch for an electric set up. I have done the searches and see arguuements both ways. Some say you gain power while othes say that power gains are offset by the alternator having to work harder. I searched and could not find anyone who had some firm data to back up their opinions.
My sense is that the alternator would work harder but that you would still come out ahead since an electrical system is more effecient than a mechanical one. Does anyone know of any firm numbers both on gain and how much harder an alternator needs to work?
No, I am not doing it for cooling. Mine runs fine with a 3 core and new water pump. Just looking at improvements.
Thanks
BSD

by adding steps to the process (mechanical to electrical to mechanical, rather than mechanical to mechanical) you will naturally have some parisitic losses and therefore an electric fan that moves the same amount of air will have to use more power. However the advantage comes that a mechanical fan wastes a lot of energy by being spinning when it really doesn't need to be.

You'll find all you need to know here:

http://www.angelfire.com/my/fan/electric.html