A/C Clutch for other belt driven equipment.

[roadyj]

Posting #2 for today. How about using an electric clutch from an automotive A/C compressor for other belt driven accessories not needed at all times? I was thinking of the power steering pump mostly. When at slow speeds it engages and turns the pump when it is more difficult to turn the wheel. While at highway speed it is disengaged when the wheel is easier to turn. Or would this be a waste of time because when you are not turning the steering wheel the pump is adding little resistance to the engine?

Any ideas of other underhood equipment that this could be used on?

Thanks