{HEAD ~ An array} of these hovering wind turbines can be used to generate {TAIL ~ large amounts} of energy 
used to generate
{ HEAD ~ An array } of these hovering wind turbines can be used to generate { TAIL ~ large amounts } of energy
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH