A set of units for assembly to form a wind turbine nacelle. The nacelle comprises a rotor-supporting assembly and generator, and a power conversion assembly and the set of units comprises a main unit arranged to be connected to a wind turbine tower and housing the rotor-supporting assembly and the generator, and at least two different auxiliary units each housing an operative component forming part of the power conversion assembly. To allow different wind turbine configurations, one of the auxiliary units can be selected from the at least two auxiliary units and assembled with the main unit to form the nacelle.

A method of generating power. An airborne power generating craft is connected to a floating structure using an aloft portion of a tether line. The floating structure is connected to an anchor using an underwater portion of the tether line. The anchor is secured to an underwater floor. Power is generated based on movement of the airborne power generating craft in response to a wind force. The floating structure is connected to an electrical transmission system through at least part of the tether line. The generated power is transmitted to the electrical transmission system.

A method of generating power using an airborne power generating craft connected to an anchor using a tether line. The anchor is secured to an underwater floor. Power is generated based on movement of the airborne power generating craft in response to a wind force. A constant length of the tether line is maintained between the airborne power generating craft and the anchor as the airborne power generating craft moves in response to the wind force. The airborne power generating craft is connected to an electrical transmission system through at least part of the tether line. The generated power is transmitted to the electrical transmission system.

A method of maintaining an offshore power plant. A power generating craft is attached to a tow cable on a floating vessel. The floating vessel is moved to an offshore power generating site. The power generating craft is maintained in an airborne state while the floating vessel is moving to the offshore power generating site. The power generating craft is detached from the tow cable and attached to a first end of a tether line at the offshore power generating site. The second end of the tether line is anchored to an underwater floor. The power generating craft is operated in an airborne state.

A method of maintaining an offshore power plant. A plurality of airborne power generating craft are landed on or near a floating vessel. Each of the plurality of airborne power generating craft forms part of the offshore power plant.

A winch for a power generating system using a tethered airborne device, the winch comprising a drum rotatable about its main axis a guiding apparatus arranged to guide an airborne device tether to wind and unwind around the drum; wherein the drum is rotatable relative to a pivot point to move in a first plane and the guiding apparatus is disposed relative to the drum to move along part of an orbital path around the drum in a second plane substantially perpendicular to the main axis of the drum, thereby allowing alignment of the winch with respect to an unwound length of the tether.

A system for electric power production from wind includes a glider having an airfoil, an on-board steering unit, a flight controller for controlling the steering unit, and a connection unit for a tether. The system further includes a ground station including a reel for the tether, a rotating electrical machine connected to the reel, and a ground station controller for controlling the reel and the rotating electrical machine. A master controller operates the system in at least first and second operation modes. In the first operation mode electric power is produced with the rotating electrical machine from rotation of the reel caused by reeling out the tether using a lift force generated upon exposure of the airfoil of the airborne glider to wind. In the second operation mode, the reel is driven by the rotating electrical machine, thereby reeling in the tether onto the reel.

The exemplary embodiments herein provide an airborne power generation assembly comprising an airborne power generation unit, a submersible platform, an electrified tether winch attached to the submersible platform, an electrified tether connecting between the electrified tether winch and the airborne power generation unit, and a power output exiting from the submersible platform. Embodiments include an underwater docking station with a docking station tether connecting the submersible platform to the underwater docking station. The submersible platform or the underwater docking station may be anchored to the sea bed. Other embodiments include winches for the sea bed anchor tethers and docking station tether.

The present invention relates to a high-altitude wind farm aircraft system. The aircraft has a plurality of wind turbines for capturing wind energy and converting same into electric energy which is stored in an onboard battery system. The electric energy, before storage, is stepped down by a transformer and converted into DC by an AC-DC converter. For use of the stored energy, the aircraft is brought to the ground and the batteries are removed to connect to a microgrid or any other electric circuit. The batteries can be installed again in the aircraft system for recharging with the aircraft going to high altitude for recharging the batteries. In one embodiment, the aircraft has an altitude indicator for indicating an appropriate altitude level for maximum efficiency of the system.

The invention relates to a rope having a length LR of at least 100 m, the rope comprising synthetic filaments with a filament tenacity of at least 1.0 N/tex, characterized in that a weight fraction χ of the total weight of synthetic filaments present in the load bearing core have a length LF of 0.01 m to 0.7*L.sub.R, wherein said weight fraction is at least 50 wt %. The invention further relates to an airborne wind power generation system comprising the rope as well as the use of the rope in an airborne wind power generation system wherein the length of the rope oscillates between a maximum length L.sub.max and a minimum length L.sub.min, wherein L.sub.max is at most 10,000 m and L.sub.min is at least 100 m and wherein the ratio of L.sub.max to L.sub.min is between 10 and 1.5.