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