Interesting story - but maybe the Sun's report includes a bit of "journalistic licence".
The Sun's article says: - "...There was no trace of the missing blade" and "Afterwards there was no trace of one of the turbine’s three huge 65ft blades — ripped off in the collision. Another was left twisted and useless...".
Whereas several other online articles state that the blade was found on the ground close by.
I would speculate that the blade fixings failed, causing it to shear off, and that the still affixed but damaged blade was bent by hitting the one that is missing, before it fell to the ground.
Or of course, it could be that there's an embarrassed alien looking for a suitable UFO repair shop at the minute.
Regards
Mike.