Wind Power Plant assembly

EKO-PRO has developed an entirely new solution regarding the assembly of an offshore wind power plant with a rotary tower.
The initial phase of the assembly, shown on Drawing 5 and Drawing 6, takes place in a harbour or berth with the use of stationary cranes, and the final assembly is completed with the use of a drum winch moored to the foundation of a neighbouring wind power plant.
The final assembly, shown on Drawing 7, is very quick and absolutely safe, because during the entire procedure of raising the wind power plant to a vertical position the bottom of the tower is already firmly fixed to the pins of the rotary sleeve and the pins are temporarily fixed to the monopile foundation.
The entire process: the making of the foundation, its initial assembly in the harbour and the final assembly, allows to save a lot of time as compared to traditional methods which require cranes and specialised equipment.
The proposed method of assembly has two further great advantages.
The first is that the floats used for the transportation of the wind power plant from the harbour to the power plant's location have a very simple structure and there may be a few sets of them. This allows to complete the assembly of a large number of wind power plants within a short time.
The second advantage is that after 20 years of work of a wind power plant or in the case of a serious failure that method allows to quickly disassemble the whole facility. During disassembly all the operations are performed in a reverse order; then worn out elements are replaced with new ones in the dockyard and the wind power plant is put back on its foundation, to work for another 20 years.

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First phase of the assembly

The first phase of assembly of a wind power plant with power output of 5 MW, as presented on Drawing 5 and Drawing 6, starts with placing the tower on front floats and on an additional temporary float which supports the tower in the mid of its length (the temporary float is not shown in the drawing). Then support floats with bracket beams are assembled and tightened with a rope in order to achieve a suitable load spread. Simultaneously, a nacelle with a hub and a rotor is being assembled on a back float. When the top of the tower has gained contact with the nacelle base these two elements are joined together with screws and the temporary float is no longer necessary. The next operation of the initial assembly is to fix the assembly unit to the tower with screws and to tie the top thereof to the top of the tower with a rope. The rope coils hanging on the pulley block will be necessary in the final phase of the assembly. Finally, the ends of the bottom of the tower are moved closer to the dummy of the foundation, which has horizontally positioned ends fixed on the pins of the rotary sleeve that are to be joined with each other at the power plant's location. Through the ballasting of the forward floaters, by way of pouring an appropriate amount of water into them, the ends of the bottom of the tower should be positioned at the level at which the ends on the pins are situated (approx. 10 m).

Final phase of the assembly

The final phase of assembly of a wind power plant with power output of 5 MW, as shown in Drawing 7, consists in placing the power plant on a monopile foundation, on which the last element thereof has already been fixed, as presented in Drawing 3, with a rotary sleeve put on it from the top. This operation requires the foundation of a neighbouring wind turbine to which an assembly barge with a winch fixed on it is moored.
The winch pulls the rope through a pulley block and therefore must bear only half of the force necessary to lift the tower.

Final operations

After the tower's floaters fall into the water, they are regulated by letting an appropriate amount of water inside. The assembly unit is dismantled, a back rudder is hauled to the tower and fixed to it in the places where the assembly unit was attached. Then the floaters must be regulated once again and the assembly is finished.