[01] The invention relates to a method for erecting a tower for a wind turbine generator using a device for erecting, said device for erecting com- prising means for shaping said tower and means for providing liquid construction material, in particular concrete.

[02] Modern towers for wind turbines are made out of steel or concrete. A steel tower generally comprises tower segments, which are piled up by a crane. The piled up tower segments are then fixed and in the end the na- celle is placed on the top of the tower.

[03] Similar methods are used for piling up concrete elements for building a tower for wind turbine generators. The concrete elements have the form of rings and are cast on-site or off-site.

[04] If a wind turbine or a tower for wind turbines shall be built up in a barren landscape or in countries where cranes for the desired building heights are not available or too expensive to use, it is a logistic challenge to build up a wind turbine generator.

[05] The problem which is solved by the invention is to improve the state of the art. [06] This problem can be solved by a method for erecting a tower for a wind turbine generator using a device for erecting, said device for erecting comprising means for shaping said tower and means for providing liquid construction material, in particular concrete, the method comprising the steps of

• feeding said liquid construction material into said means for shaping at a bottom, thereby conducting a vertical launching process;

• pushing the liquid construction material upward during hardening or after hardening, so that said liquid construction material shapes said tower by hardening and moving upward;

• feeding more of said liquid construction material underneath the hardening or hardened liquid construction material.

[07] Thereby a method can be provided in which a crane is not necessary, or the ultimate load of the crane can be rather low, and/or the costs can be reduced.

[08] The following expressions can be understood as follows:

[09] The "means for shaping" comprises all kinds of form work, especially out of wood or steel, which in particular form a ring, especially a circular ring. The means for shaping can also be adjustable so that the diameter of the tower can be varied. [10] The "liquid construction material" can comprise concrete, metal, steel, and synthetic materials which can be brought into a liquid phase and which establish a solid state after hardening. A "liquid" phase is present when a solid state is not established and construction material can be formed without destruction.

[11] A "bottom" can be the construction area itself and is in general underneath the tower segment which is currently built up. The bottom will usually be roughly at ground level.

[12] The "pushing" can take place by feeding new liquid construction material into the tower so that parts which are already hardened are lifted up by the newly fed liquid construction material. The pushing can also take place by a lifting device which lifts already hardened tower segments, for example by several meters, so that a further feeding can take place which builds up a new tower segment. [13] This method can of course be combined with a conventional way of erecting a tower for a wind turbine.

[14] In a further embodiment, said feeding is carried out in a continuous or in semi continuous way.

[15] In the continuous way, a constant feeding with liquid construction material at a bottom of the tower takes place so that thereby the tower can gain height. [16] In the semi continuous way, liquid construction material is filled into the means of shaping. After this the providing of the liquid construction material is set out until a hardening of the liquid construction material took place. Then this hardened and formed tower segment is lifted or will be lifted by newly fed or otherwise newly provided liquid construction material. Thereby, alternatives for building up the tower are provided.

[17] To build up a stable tower with an economic use of construction material, in a further embodiment said means for shaping said tower increase a diameter of said tower during the erecting procedure. [18] The term "diameter" is explicitly not limited to a tower with a circular base area. Rather, it also applies for other base area forms like e.g. rectangular forms, square forms, or elliptical forms.

[19] In a further embodiment, a reinforcing is introduced into the liquid construction material before hardening. Thereby, the tensile strength of the tower can be increased.

[20] For the use of the tower as a tower for a wind turbine generator, in a further embodiment on a top of that tower, a nacelle can be placed. Such a nacelle bears for instance a generator and a gear box.

[21] In a further embodiment, the nacelle is placed on the top of the tower at the beginning of said method so that by erecting said tower, said nacelle will be lifted up. [22] For the reason that the nacelle can be an adjusted according to the wind regime, a transmission building element can be implemented between nacelle and tower.

[23] In a further embodiment, the transmission building element can be prefabricated in a preceeding step and comprises in particular bearing elements. With the prefabricated bearing element, a very accurate transmission from tower to nacelle can be realized.

[24] In a further aspect, the problem can be solved by a tower for a wind turbine generator wherein said tower is built according to a method like it was described before.

[25] In an additional aspect, the problem can be solved by a wind turbine tower which is formed integrally out of a liquid construction material. Therefore, it is not nessassary to have prefabricated concrete tower elements which are piled up by a crane. [26] In another independent aspect, the problem can be solved by a wind turbine generator wherein said wind turbine generator comprises a tower like it was described before.

[27] In a further aspect, the problem can be solved by a wind farm wherein said wind farm comprises a wind turbine generator like it was de- scribed before. [28] An exemplary embodiment is described below, with reference to the drawing, in which shows

Figur 1 three erecting stages of a tower for a wind turbine generator with a nacelle on its top. [29] In the beginning, on the device for erecting 100, a bearing element 103 is placed on top. Then, liquid concrete is filled in means for shaping the tower 109, so that the liquid concrete is in contact with the bearing element 103. By hardening, the concrete establishes a fixed connection 111 with the bearing element 103. On the bearing element 103, the nacelle 105 is placed. As a result, the nacelle can be adjusted according to a wind regime by servo motors.

[30] In a first alternative, the hardened concrete which builds a tower segment 115 will be lifted up by a lifting device (not displayed), and at a bottom 113 liquid concrete is fed through a feeding inlet 107 into the means for shaping 109. Thereby, a further tower segment 117 is built up which is underneath the tower segment 115. By repeating this procedure, the tower grows so that the wind turbine generator can be used.

[31] In another alternative, the concrete is constantly fed into the means for shaping 109 so that the nacelle is slowly lifted up. The feeding takes place so slowly that an upper part which overtops the means for shaping 109 has already hardened. [32] In the end, the tower for the wind turbine generator and the nacelle are at in their final positions. A crane for erecting was not nessassary.