I have a 2012 Mini Cooper JCW n14, when I accelerate I hear kind of an annoying whiny fan noise (AC is not on), any ideas on what it might be? (video link)

 

Video doesnt work, maybe upload to youtube?

 

Woops sorry guys, try this link:

 

well it def. increases to match acceleration, something driven by the serpentine belt??
liftng the hood and having someone rev the engine slowly can you hear which side its coming from?
front back driver passenger sides?