Power is mechanically transmitted from a tethered airship carrying wind turbines to electrical generators on the ground at the anchor point of the tether, by the use of endless power-transmission cables bridging between drive sheaves at the turbine wheels and driven sheaves at the generators. Tether...http://www.google.com/patents/US4166596?utm_source=gb-gplus-sharePatent US4166596 - Airship power turbine
