Hazard navigation light for wind turbines

A wind power installation includes a pylon and a machine housing mounted thereon. The pylon accommodates the rotor of the wind power installation and the generator for producing energy. Wind power installations can be provided with signaling devices so that the attention of air traffic is drawn to the existence of the wind power installation as a large structure. The flight lighting arrangement produces a light which is visible over a long distance, preferably a flashing light. A cover arranged with the flight lighting arrangement can substantially prevent the light from the flight lighting arrangement from being visible, from the ground, in a region around the wind power installation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention concerns a wind power installation.

2. Description of the Related Art

Wind power installations have long been known. They usually consist of a number of components such as a pylon and a machine housing which is mounted thereon and which accommodates the rotor of the wind power installation and the generator connected thereto for producing energy. Whenever such wind power installations are located within air traffic zones, that is to say those regions which are directly in the relative proximity of airports, such wind power installations must be provided with certain signaling devices so that the attention of the air traffic is drawn to the existence of the wind power installation as a large structure, in good time.

Signaling devices can also be coats of paint on the rotor blades (in particular the tips thereof) of the wind power installation.

General guidelines for identifying obstacles to air travel are known from ‘Nachrichten für Luftfahrer’ [‘News for Pilots’], Part I, NfL I 15/00, 27th Jan. 2000.

The various flight lighting arrangements are also mentioned therein. Another flight lighting arrangement is known from DE-U-200 08 289.

BRIEF SUMMARY OF THE INVENTION

In one aspect, embodiments of the invention reduce disadvantages of flight lighting arrangements.

In the wind power installation having one embodiment of a flight lighting arrangement is a flashing signaling device with a cover which prevents the flashing signaling device from being visible in a given cone (viewed from the flight lighting arrangement) laterally of the wind power installation as seen from the ground. The opposing sides of the cone can be separated by an angle of at least 45°, preferably 90°-150°, or even equal or greater than 180° (horizontal). Such a cover prevents a view of the flight lighting arrangement when the flight lighting arrangement is viewed from within a region defined by the cone around the wind power installation, but normal air traffic may still recognize the light of the flight lighting arrangement from a distance.

In one embodiment, the cover is a mirrored surface with a parabolic configuration that causes the flashing signal to appear in strengthened form and more easily visible to the air traffic.

In another aspect, an embodiment provides an advantage in that the flight lighting arrangement can substantially reduce the light pollution for a residential population in the region around the wind power installation.

Depending on the respective height of the flight lighting arrangement, an angle of 150° or more can mean that, as viewed from the ground, the light from the flight lighting arrangement is not seen at a distance of 0 to 2000 m, preferably at least up to 1000 m, from the region around wind power installation. This means that the light from the flight lighting arrangement may no longer be a burden in adjoining or nearby residential areas.

The invention is described in greater detail hereinafter by means of several embodiment.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a plan view of a wind power installation1comprising a pylon and a machine housing2mounted thereon as well as the rotor3of the wind power installation and the machine housing casing (pod)4. As can be seen inFIG. 2provided on the pod is a flight lighting arrangement5which is caused to flash from time to time or constantly by a suitable control (not shown). Provided below the flight lighting arrangement is a cover6which prevents the light of the flight lighting arrangement from being visible from the ground in a region around the wind power installation. That region can be defined by a cone diameter of, for example 2000 m, as formed on the ground around the wind power installation. In one embodiment, the light from the flight lighting arrangement cannot be seen in a region of up to about 1000 m around the wind power installation. The region around the wind power installation from which light from the flight lighting arrangement5is substantially blocked may vary based upon the height of the wind power installation, the shape and size of the cover6and/or pod4, and the ambient light conditions at the time of viewing. The volume from which light from the lighting arrangement may not be visible, as discussed herein, may be more accurately described as a cone frustum in which the top portion of the cone is truncated (i.e., the light emitted from the flight lighting arrangement above the cover6is visible in the apex region of the cone and at a distance therefrom as illustrated inFIG. 3b).

The shape of the region may correspond to a shape of the cover6or pod4. For example, if the cover6comprises a large circular disc, then the light of the flight lighting arrangements5would not be visible in a conical region below the disc. Depending on the respective diameter of the disc, the covered (e.g., non-lit region) area can be larger (increase in the cone angle, as defined by an apex of the cone above the cover and illustrated inFIGS. 2 and 3b). If the cover6of the flight lighting arrangement5is parabolic in shape (FIG. 3a) or box-shaped (FIG. 3c), the cone angle can be up to 180°. A cone angle of 180° or greater may prevent the flight lighting arrangement5or light therefrom from being viewable from the ground. Thus, when the cone angle is less than 180°, the light from the flight lighting arrangement5is practically no longer visible below the slanted lines defining the sides of the cone (seeFIGS. 2 and 3), with respect to the flight lighting arrangement5. Large angles, as described, are usually unnecessary as the flight lighting arrangements5of the wind power installations are often located relatively high with respect to the surrounding buildings.

If the cone angle is about 160 to 170°, then the light of the flight lighting arrangement5may not be visible in a region of about 500-2000 m laterally of the wind power installation, but may be visible by the flight traffic.

In principle, it is possible for the cover6of the flight lighting arrangement5to be such that it is always only the same region in a given lateral region of the wind power installation that is covered. If that cover6is stationary or can be adjusted by motor means (upon rotation of the pod about the point of rotation), therefore, in such an embodiment, only the selected region laterally of the wind power installation that is covered, independently of an azimuth angle of the wind power installation. AsFIGS. 3a-3dshow, various configurations of the cover6can be envisaged. In that respect it is the position of the outer edge7of the cover6that determines the coverage area (i.e., cone diameter).

The higher or more extended that outer edge7is taken, the correspondingly greater is the cone angle and the correspondingly greater is the cone diameter of the region around the wind power installation.

The intensity of the light from the flight lighting arrangement decreases with the distance from the wind power installation, thus it may be sufficient if the cover provides a ‘shadow range’ of about 1500 to 3000 m, or markedly less, around the wind power installation.