System of anchoring and mooring of floating wind turbine towers and corresponding methods for towing and erecting thereof

Abstract

A system of floating and weight-stabilized wind turbine towers with separately floodable compartments and aerodynamic overwater encasement and the appertaining semisubmersible mooring structures including anchorage on the seabed, a horizontally floating underwater mooring meshwork and an actinomorphic buoy-cable-mooring to the wind turbine towers. Also, a method to transport wind turbine towers from the manufacturing plants on-shore to the final off-shore destination by towing the vented towers in a horizontal position with towboats. Further, a method to erect the wind turbine towers at the final destination, including the assembly of the wind turbines. The worldwide potentials of off-shore wind farming in deep waters to produce electricity in an ecologically and economically sound way in order both to satisfy men's requirements and to help to reduce the need to rely on critical fossil and nuclear resources being immense.

Description

TECHNICAL FIELD[0001]The present invention relates to an off-shore windfarming structure based on floating and weight-stabilized wind turbine towers with compartments and aerodynamic overwater profile, moored by ropes, a net of horizontally floating underwater cables and vertical lines anchored on the seabed, altogether forming a windpark, and the methods to erect these structures. The system is suitable to carry down- or upwind operating wind turbines typically comprising nacelles, horizontal axles and radially mounted blades as well as to serve as guiding structure for electrical transmission cables from the wind turbine towers to the collector stations of the windpark.BACKGROUND OF THE INVENTION[0002]Worldwide energy consumption is increasing steadily and rapidly. The international community strives, therefore, to introduce and expedite non-fossil and non-nuclear energy production in order to slow down climatically critical CO2 emissions and to avoid risks and consequential costs...

AI Technical Summary

Benefits of technology

The present invention provides a system for carrying, transporting, and erecting offshore wind turbines that is more efficient and cost-effective than existing systems. The system includes a tower that can align itself with the wind direction, reducing wind load and drift forces, and maintaining dynamic balance. The tower is placed in a slide ring near the water surface, acting as a wind vane. The mooring system includes weight anchors and vertical mooring lines, chains, or cables, which are maintained in an upright and taut position by buoys or major buoys. The buoys or major buoys help to reduce physical strain on the mooring lines and chains.

Problems solved by technology

Worldwide energy consumption is increasing steadily and rapidly.

Due to large areas worldwide exposed to strong and steady seasonal or all-the-year winds, the potentials of wind power are enormous.

The efficiency of wind turbines with two or three blades and horizontal axles is high and can hardly be improved due to the laws of physics.

Transmission of electrical power under water is only feasible with direct current.

The disadvantages of off-shore windparks (regardless of whether the towers are fixedly anchored in the seabed or whether they are freely floating [though not drifting] or whether they are semisubmersible) are the necessity to operate with high voltage direct current (HVDC) transmission over very long distances until power can be converted onshore into alternative current to be fed into the grid, the exposure of wind turbines and their supporting structures to aggressive saliferous air and spindrift as well as the fact that shipping or towing of modules or entire off-shore wind power units including their platforms to the energy production sites and the assembly and / or erection of existing systems is complicated and cost-intensive.

Mono-piles of wind turbine towers fixedly anchored are exposed to enormous leverage forces at or near the seabed.

Especially floating and—to a lesser extent—semisubmersible wind towers tend to wobble when towers incline under wind load because of the changing angular momentum.

This leads to a disturbed running of mechanics, increasing material fatigue, in particular of the bearings of the nacelle freely rotating around its own axis.

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