Fiat Seicento screeching sounds...what is it? 

I initially had an intermittent screeching problem with my car. Was screeching worse under load as the demand for current rose with the lights on, heater on etc.. Fan belt broke in January. I replaced it, no change with the intermittent screeching. This last week it has got worse, today, I took some excessive slack out of the belt by adjusting the alternator position on the pivot. After adjusting and restarting, the problem is no better, it now screeches PERMANENTLY as it did before adjusting. Does anyone have a clue what is going on here please? Is that the sound of shot bearings?
Video made using my Samsung GT-1900 Galaxy S smartphone (Froyo 2.2)