By this, unnecessary frequent swiveling of the nacelle is avoided and also {TAIL ~ a large amount} of {HEAD ~ electricity} for swiveling the nacelle is saved 
By this , unnecessary frequent swiveling of the nacelle is avoided and also { TAIL ~ a large amount } of { HEAD ~ electricity } for swiveling the nacelle is saved
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH