Lighting system and method for improving plant growing conditions

Abstract

A lighting system (3) for providing photosynthetically stimulating artificial light to a designated target area in need of such light, the lighting system (3) comprising at least one illuminator (1) having a light source. The illuminator (1) emits photosynthetically stimulating light at a narrow beam angle (FWHM) of less than or equal to 20°, the lighting system (3) comprising means for positioning the at least one illuminator at a distance of at least 20 m from the designated target area measured along the beam direction, and the illuminator (1) being adapted to irradiate the designated target area with a photosynthetic photon flux density of at least 140 μmol / s / m<supgt;2< / supgt>. Also described is a method for improving plant growth conditions by exposing plants to photosynthetic artificial light from a light source to improve the growth conditions of plants in need of light at a designated target area.

Description

Technical Field

[0001] The present invention relates to a lighting system comprising a luminaire for illuminating plants to improve their growing conditions. The plants may cover an area such as at least one area of ​​a lawn of a stadium. The lighting system may comprise one or more luminaires for illuminating the plants. The plants may cover an area such as a lawn of a stadium, a golf course or a grass field. The lighting system may be independent, without natural light or provide supplementary light to sunlight. The present invention also relates to a method for improving plant growing conditions. Background Art

[0002] As the popularity of football and the rate of money turnover increased, the size of sports fields used for football also increased. Stadiums with a capacity of 40,000 to 80,000 spectators are very common. Ensuring a high quality natural grass field can be challenging, especially in large stadiums. The walls and roofs of the stadium block sunlight from reaching the grass. Since grass plants need light for photosynthesis, a lack of sunlight results in poor grass growth and poor quality.

[0003] The same problem applies to other stadiums (e.g. tennis courts with grass surrounded by stands, football and rugby fields with stands). Other sports are also played on natural grass. Even training grounds that are not surrounded by stands require supplementary lighting due to high wear and tear.

[0004] The use of artificial light to improve plant growth in greenhouses is well known.

[0005] The need to provide artificial light to stimulate photosynthesis of lawns in sports stadiums is known. Patent EP1164830B1 discloses a system for promoting the growing conditions of grass and other plants in lawns for indoor and outdoor sports and competitive sports, in particular lawns where natural light conditions are reduced due to shading from stands. The system comprises a mobile unit carrying luminaires for illuminating the lawn. The system is arranged to be used as a mobile greenhouse and is placed on the lawn. Similar mobile units have been developed in the past 20 years. The luminaires are typically located at a height of 1m to 4m above the lawn.

[0006] These units require storage space between the operations that are performed regularly, which is a disadvantage. Stadiums, especially old stadiums, are not equipped with storage space for mobile units. Therefore, the mobile units are transported out of the stadium when not in use. Since old stadiums are usually located in cities, the availability of storage space outside the stadium may also be limited. These units are equipped with wheels for mobility, and the wheels rub on the grass, which is a disadvantage. Alternative solutions for mobile units are disclosed in patent US6874275 and patent application EP3192350. Patent application EP3192350 discloses a lifting / lowering device including a lamp, which lowers the lamp to a working distance of 0.05m to 2.0m above the grass to provide sufficient artificial light to promote the growth of grass. The lamp can be an LED lamp specially developed for photosynthesis and the illumination level at the working distance is 100µmol / s / m 2 Up to 200µmol / s / m 2 .

[0007] Stadiums also require artificial light for floodlit sporting events, particularly during events such as late at night when there is little sunlight. Floodlighting for stadiums is well known in the art. It is known that currently advanced modern floodlighting systems utilize light sources in the form of light emitting diodes (LEDs) and are even arranged to provide light shows. Typically, the distance from the field or court to the light source is greater than 30 meters, and the distance can exceed 50 meters.

[0008] It is well known that illumination decreases with the square of the distance. This is known as the Inverse Square Law of Light. For example, increasing the distance between the light source and the illuminated area from 1m to 10m reduces the illumination on that area to 1%. The light from modern floodlighting systems is not sufficient in terms of luminous intensity to promote the growth of grass on a sports field. Due to the implications of the Inverse Square Law of Light, those skilled in the art have come to believe that artificial lights used to promote grass growth should be positioned close to the lawn, and a distance of 4 meters seems to be the upper limit in current practice. Summary of the invention

[0009] An object of the present invention is to remedy or alleviate at least one disadvantage of the prior art, or to at least provide a beneficial alternative to the prior art.

[0010] This object is achieved by the features specified in the following description and in the subsequent claims.

[0011] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0012] In this article, beam angle is defined as the angle between two directions relative to each other for the beam axis at which the luminous intensity is half of the maximum luminous intensity. This corresponds to the so-called full width at half maximum (FWHM) beam angle.

[0013] In a first aspect, the present invention relates to a lighting system for providing photosynthetically stimulating artificial light to a designated target area requiring photosynthetically stimulating artificial light, the lighting system comprising at least one luminaire (1) having a light source. The luminaire (1) emits photosynthetically stimulating light at a narrow beam angle (FWHM) of less than or equal to 20°, the lighting system (3) comprising means for positioning the at least one luminaire at a distance of at least 20 m measured along the beam direction from the designated target area, and the luminaire (1) is adapted to provide photosynthetically stimulating artificial light at a minimum of 140 µmol / s / m 2 The photosynthetic photon flux density illuminates the specified target area.

[0014] Photosynthetically stimulating light is also called grow light. PPFD is the number of photosynthetically active photons (in the PAR region: 400nm-700nm) falling on one square meter of a given surface per second (µmol / s / m 2 ).

[0015] The luminaire may emit photosynthetically stimulating light at a narrow beam angle (FWHM) of 3° or more, such as 4° or more, such as 5° or more.

[0016] The narrow beam angle (FWHM) may be from 3° to 15° (such as from 4° to 15°, from 5° to 15°, from 6° to 15°). The narrow beam angle (FWHM) may be from 3° to 10° (such as from 4° to 10°, from 5° to 10°, from 6° to 10°).

[0017] The illuminator can measure a minimum of 140 µmol / s / m at a distance of at least 25 m (e.g. 30 m, e.g. 35 m, e.g. 40 m, e.g. 45 m, e.g. 50 m or more) from the illuminator in the direction of the beam. 2 (10,000 lux) to illuminate the designated target area.

[0018] The illuminator can measure a minimum of 210 µmol / s / m at a distance of at least 20 m (e.g. 25 m, e.g. 30 m, e.g. 35 m, e.g. 40 m, e.g. 45 m, e.g. 50 m or more) from the illuminator in the direction of the beam. 2 (15,000 lux) (e.g. 280 µmol / s / m 2 (20,000 lux), e.g. 350 µmol / s / m 2(25,000 lux)) to illuminate the designated target area.

[0019] The target area may be illuminated with an illumination uniformity of at least 0.6, such as an illumination uniformity of 0.8, such as an illumination uniformity greater than 0.8. Lighting uniformity is defined herein as a ratio of minimum illumination to average illumination on a surface.

[0020] The illuminator may comprise a light source in the form of a light emitting diode (LED). The illuminator may also comprise a light source in the form of a laser diode. The illuminator may comprise a high pressure sodium (HPS) lamp. The illuminator may comprise a metal halide (MH) lamp.

[0021] The luminaire may emit light having a correlated color temperature greater than 2700 K. Light having a correlated color temperature greater than 2700 K may include white light having a correlated color temperature such as 2700-3500 K (warm light), 3500-4500 K (neutral white), 4500-5500 K (cool white), or 5500-6500 K (cool light / daylight). The luminaire may also include a light source that emits light in a narrower wavelength range (such as a light emitting diode that emits blue and red light).

[0022] The luminaire may be mounted in such a way that it points in a fixed direction, or the luminaire may be tilted so that light is emitted in several directions. The light source in the luminaire may also be tilted relative to the luminaire. The luminaire may include an adjustable optical device that can change the direction of the light beam emitted from the luminaire.

[0023] The apparatus for positioning at least one luminaire may include an edge portion of a roof of a stadium. The luminaire may be movably mounted to an edge portion of the roof of the stadium. The luminaire may be mounted to a movable object arranged on the edge portion of the roof of the stadium. In an alternative embodiment, the apparatus for positioning at least one luminaire may include at least one light pole on which the luminaire is mounted. The light pole may be located outside the lawn of the stadium. The light pole may be located in a greenhouse. The light pole may be located on a golf course. On the golf course, the pole may be telescopic and arranged to be hidden when not in use. The pole may be rotatable about its longitudinal axis. The pole may be mounted on a truck. The light pole may be located on a farm field. The farm field may be a strawberry field.

[0024] The lighting system may comprise a plurality of poles, and each pole may be provided with at least one luminaire.

[0025] In an alternative embodiment, the means for positioning at least one luminaire may include a tower. In another alternative embodiment, the means for positioning at least one luminaire may include a stadium structure (such as a wall, a roof over a building, a platform or a stand). In another alternative embodiment, the means may include a structure spanning and above the turf at the stadium. The at least one luminaire may be suspended from a structure spanning and above the turf. The means for positioning the luminaire may include a combination of two or more of an edge of a stadium roof, a pole, a tower, a roof over a stadium structure, a wall, a building, a platform or a stand, and a structure spanning and above the turf at the stadium.

[0026] The luminaires that make up the lighting system can all emit circular beams that provide a circular footprint on the lawn when the light is directed vertically downwards and an elliptical footprint on the lawn when the luminaire illuminates the lawn at a certain angle. The size of the circular or elliptical footprint depends on the beam profile of the luminaire and the distance from the luminaire to the lawn.

[0027] The target area of ​​the lighting system may advantageously be divided into a regular grid pattern (or, alternatively, a hexagonal pattern). The number of points in the grid may be equal to the number of luminaires in the lighting system. If the target area is smaller than the total capacity of the lighting system, the number of activated luminaires in the lighting system may be equal to the number of points within the target area.

[0028] The luminaires that make up the lighting system can be installed in a manner such that the central axis or central beam of each luminaire is directed to a dedicated position corresponding to a grid point on the target area. In this case, the lighting system can be arranged in a manner such that the circular or elliptical footprints from the individual luminaires overlap.

[0029] The potential to obtain uniform lighting levels is very important for energy consumption and can also be very important for the resulting visual appearance of the lawn. In order to obtain acceptable lighting uniformity, the arrangement with respect to the footprints of the individual luminaires is very important. The inventors have determined through simulations that acceptable lighting uniformity is obtained when the footprints from the individual luminaires overlap in such a way that the intensity level of two adjacent footprints both drops to approximately 50% halfway between the center points of the two footprints.

[0030] It can be concluded that in order to obtain acceptable uniformity, the lighting system should consider: the number of luminaires, the beam profile of the luminaires, and the distance and angle from the luminaires to the corresponding grid points on the lawn. By combining and optimizing these factors, a uniformity greater than 0.80 should be obtained under normal circumstances.

[0031] The lighting system may include a monitoring system for monitoring and estimating the need for artificial lighting over all portions of the target area to obtain acceptable growing conditions for the grass. The lighting system may include a monitoring system for monitoring light conditions (including sunlight conditions) in at least one area of ​​the lawn. The monitoring system may include a camera or a plurality of cameras.

[0032] The lighting system may be adapted to distribute floodlighting for sporting events. Typically, floodlighting does not have the same intensity requirements as artificial lighting for grass growth (i.e., grow lighting). Each luminaire may supply light to a fixed area within a target area, and each luminaire may be dimmed and dimmed or turned on or off individually.

[0033] The invention also relates to a floodlighting system for illuminating a lawn of a stadium, wherein the floodlighting system comprises a lighting system as described above.The stadium may be a stadium intended for sports such as soccer, American football, rugby, baseball, cricket, golf, tennis or similar sports.

[0034] In a second aspect, the present invention relates to a method for improving plant growth conditions, by exposing the plants to photosynthetic artificial light from a light source to improve the growth conditions of plants requiring light at a designated target area. The method comprises providing a luminaire comprising a light source, the luminaire being adapted to emit photosynthetic artificial light at a narrow beam angle (FWHM) of 20° or less. The light source is located at a distance of a minimum of 20 m from the designated target area and emits a minimum of 140 µmol / s / m 2 The photosynthetic photon flux density illuminates the plants in the specified target area.

[0035] The method may include providing a luminaire that emits photosynthetically stimulating light at a narrow beam angle (FWHM) of 3° or more, such as 4° or more, such as 5° or more.

[0036] The method may include providing a luminaire that emits photosynthetically stimulating light at a narrow beam angle (FWHM) from 3° to 15° (e.g., from 4° to 15°, e.g., from 5° to 15°, e.g., from 6° to 15°). The narrow beam angle (FWHM) may be from 3° to 10° (e.g., from 4° to 10°, e.g., from 5° to 10°, e.g., from 6° to 10°).

[0037] The method may include measuring a minimum of 10,000 lux or 140 µmol / s / m at a distance of at least 25 m (e.g. 30 m, e.g. 35 m, e.g. 40 m, e.g. 45 m, e.g. 50 m or more) from the light source in the direction of the light beam. 2The method may include measuring a minimum of 210 µmol / s / m at a distance of at least 20 m (e.g. 25 m, e.g. 30 m, e.g. 35 m, e.g. 40 m, e.g. 45 m, e.g. 50 m or more) from the light source in the direction of the light beam. 2 (15,000 lux) (e.g. 280 µmol / s / m 2 (20,000 lux), e.g. 350 µmol / s / m 2 (25,000 lux)) to illuminate the target area.

[0038] The vegetation may be grass in a sports stadium such as a gymnasium. The vegetation may be grass in a sports field such as a golf course.

[0039] A lighting system that promotes plant growth and is arranged to be mounted to a fixed structure placed outside the lawn of a stadium has several advantages as a system for providing artificial light to the lawn. Known mobile lighting systems that are arranged to be positioned on the lawn are time consuming to operate. Workers must spend time positioning one or more mobile rigs on and off the field and moving them from one area of ​​the field to another. In addition, the mobile lighting system occupies an area of ​​the field at least during the period when it is in use, which may prevent other activities from being carried out in the area of ​​the field during this period. Mounting the lighting system to a fixed structure away from the field means that it does not occupy any area of ​​the field, and activation or deactivation of the system is quick and easy.

[0040] Another positive effect of the lighting system according to the present invention compared to the prior art is that prior art mobile drilling rigs require storage space for storage when not in use. The lighting system according to the first aspect of the present invention will typically be fixed to a structure off-site (such as a roof or one or more light poles) and will not require any storage space.

[0041] The lighting system according to the first aspect of the invention may typically be arranged to project light in a spectral range known as photosynthetically active radiation (PAR) and having a wavelength range between 400 nanometers and 700 nanometers. Since studies have shown that grass can use light in certain spectrums more efficiently (particularly light in the wavelength range between 400 nanometers and 500 nanometers (blue light) and light in the wavelength range between 600 nanometers and 700 nanometers (red light)), the lighting system may be arranged to emit light in one or both of these spectrums. The lighting system may be arranged to emit light in a certain spectrum during a certain time period and in another spectrum during another time period. Emitting light in a spectrum that is particularly beneficial to plant growth can be energy-efficient and advantageous, particularly when there is little need to use the lighting system to provide heat from the light to the herbaceous plants.

[0042] The lighting system may include at least one luminaire including a light source in the form of a light emitting diode (LED). The lighting system may include a plurality of luminaires. All or some of the plurality of luminaires may include LEDs. LEDs may be very advantageous for several reasons:

[0043] - The spectrum to be emitted can be customized by using colored LEDs;

[0044] - LEDs can be energy-efficient compared to other light sources;

[0045] -LEDs can be dimmed or turned on and off instantly;

[0046] -LEDs have a long life expectancy;

[0047] -LED does not provide blinking; and

[0048] - Small light sources such as LEDs make it more feasible to obtain luminaires with narrow beam angles.

[0049] In contrast to HPS lamps, which take considerable time to turn on again when turned off, LEDs can be dimmed or turned on and off instantly.

[0050] At least one luminaire of the lighting system may emit light having a beam angle (FWHM) of approximately 12°. The luminaire of the lighting system may emit light having a beam angle (FWHM) of less than 12° (e.g., 11°, e.g., 10°, e.g., 9°, e.g., 8°, e.g., 7°, e.g., 6°, e.g., 5°, e.g., 4°, e.g., 3°). A narrow beam may be very beneficial for supplying light from the luminaire to a defined area of ​​the lawn. Thus, compared to a light source with a wider beam, energy may be spent to a greater extent on illuminating areas of the lawn that require artificial light, while limiting energy losses due to illuminating areas of the lawn that do not require supplementary light. In some cases, it may be beneficial to have the luminaire emit light having a wider beam so that the luminaire covers a larger area of ​​the lawn. This may be beneficial at the central area of ​​a large target area such as a football field, for example, to increase uniformity. However, closer to the edge of such an area, it is very beneficial to use light having a narrow beam angle so as not to waste light outside the target area. Therefore, lighting with a narrow beam angle will save energy. Narrow beams enable luminaires to distribute light over a target area and reduce the amount of light outside the target area. The size and location of the target area may change rapidly due to changes in natural lighting conditions. Therefore, it may be beneficial for all luminaires in a lighting system to have narrow beam angles. By turning such luminaires on or off, it is quick and easy to illuminate a more restricted target area, such as an area of ​​a football field that is shielded from direct sunlight.

[0051] The light source or luminaire of the lighting system may be tiltable so that the direction of the light emitted from the luminaire can be changed. The light source or luminaire can be tilted in any direction. Having a tiltable light source or luminaire enables the area of ​​the lawn that is exposed to the light from the light source or luminaire to be moved. This may be beneficial, for example, to reduce the number of luminaires required to supply lighting to a large area such as a football pitch. The luminaire may also include an adjustable optical device that can change the direction of the light beam emitted from the luminaire. This may have the same benefits as a tiltable luminaire.

[0052] The lighting system may comprise means for changing the beam angle of light emitted from the luminaire. The luminaire may be arranged with such a beam changing means. The light source within the luminaire may be provided with a beam changing means to change the beam angle of the luminaire. The beam changing means may be an optical means for focusing or dispersing the light emitted from the light source. The beam changing means may be adjustable.

[0053] The grow lighting system may comprise a beam altering device for altering the beam profile of the light from the illuminator. Thereby, the radius of the light footprint from the illuminator may be increased or decreased.

[0054] The lighting system may comprise at least one luminaire mounted approximately at the height of the roof of the stadium. This may be particularly important when the same luminaire is used both for stimulating plant growth and for floodlighting of the stadium.

[0055] To save costs, it may be beneficial that some of the luminaires or some of the light sources in the luminaires can be adapted to provide grow light as well as flood lighting as required. Flood lighting typically has a beam angle greater than 20°. It may be useful to apply a beam changing device to some of the luminaires in the lighting system to change a narrow beam suitable for grow lighting to a wider beam suitable for flood lighting.

[0056] Typically, providing grow lighting to a stadium requires several times more light than providing flood lighting to a stadium. Therefore, a flood lighting system for the entire stadium may be adapted to supply grow light to a defined portion of the field, such as 1 / 5 of the field. For this adaptation, it may be useful to apply tiltable luminaires or luminaires comprising adjustable optics that can change the direction of the light beam emitted from the luminaire. Additionally, for this adaptation, it may be useful to apply luminaires with a beam changing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In the following there is described an example of a preferred embodiment shown in the accompanying drawings, in which:

[0058] Figure 1 A schematic diagram showing an illuminator of a lighting system for stimulating plant growth;

[0059] Figure 2 shows the use of 506 Figure 1 A simulated contour map of the light intensity contours of the illuminator illuminating a target area having a length of 100 meters and a width of 64 meters;

[0060] Figure 3 shows the use of 306 Figure 1 A simulated contour map of the light intensity contours (lux) of the luminaire illuminating a target area having a length of 104 meters and a width of 68 meters;

[0061] Figures 4 to 6 Schematically shows how the lighting system according to the present invention illuminates a lawn;

[0062] Figure 7 Schematically shows the Figures 4 to 6 The same view, but with partially overlapping beams; and

[0063] Figure 8 The footprint of one light beam from one luminaire on the ground is shown schematically and not to scale, and a graph of the full width at half maximum (FWHM) defining the beam angle is shown. DETAILED DESCRIPTION

[0064] In the drawings, reference numeral 1 denotes a lighting device. The lighting device 1 includes a plurality of LEDs (not shown). The lighting device 1 includes a frame 13. Figures 4 to 7 As shown, the luminaire 1 is shown with a fixing iron 15 for fastening the luminaire 1 to the support 2. The luminaire 1 comprises a tilting device 17 for adjusting the angle of the frame 13 relative to the fixing iron 15.

[0065] The luminaire 1 is powered with sufficient power, such as about 2500 W. The LEDs may emit white light with a correlated color temperature of about 4000 K. The luminaire 1 emits light having a narrow beam 19. Figure 8 As shown, the luminaire 1 can emit light at a beam angle 10 of 5.5°.

[0066] Figure 2 A simulated contour map showing the light intensity contours is shown. The calculations are based on a football field that is 100 meters long and 64 meters wide. Figure 1 The luminaire 1 shown is located 32m above the ground, and 506 luminaires 1 are evenly distributed over the field so that the beam 19 is perpendicular to the ground. The simulation shows that the center of the field is illuminated with an intensity above 20,000 lux, and most of the field is illuminated with an intensity close to or greater than 20,000 lux.

[0067] Figure 3A simulation based on 306 luminaires evenly distributed over a football field 104 meters long and 68 meters wide such that the beam 19 is perpendicular to the ground is shown. The simulation shows that the center of the field is illuminated with an intensity above 10,000 lux, and most of the field is illuminated with an intensity close to or greater than 10,000 lux.

[0068] Figure 2 and Figure 3 The simulation diagram shown shows that the lighting system 3 according to the invention is able to illuminate grass at a certain distance to stimulate grass growth.

[0069] Figures 4 to 7 The schematic diagram shows how the lighting system 3 illuminates the lawn 4. Figure 4 In FIG. 4 , a plurality of luminaires 1 are mounted on a support 2 (schematically shown as a roof 5 of a stadium 6 ). The plurality of luminaires 1 illuminate the entire lawn 4 . Figure 5 to Figure 6 In the example, multiple illuminators 1 illuminate 1 / 3 of the lawn. Multiple illuminators 1 are tiltable. Thus, the entire lawn 4 can be illuminated by continuously adjusting the angle of the illuminators 1. Figure 7 In the embodiment of FIG. 1 , less than 1 / 3 of the lawn is illuminated. The light beams 19 overlap to increase the light intensity at the edge of each of the sites 7 produced by the light beams 19 .

[0070] Figure 8 The footprint 7 of the beam 19 from one luminaire 1 on the ground 40 is shown. Light is emitted from the luminaire 1 at a beam angle 10 of 5.5° (measured from the edge 130 of the frame 13 of the luminaire 1). The footprint 7 is calculated based on the luminaire 1 being mounted 32m above the ground 40 and the beam 19 being oriented perpendicular to the ground 40. The dimensions are for illustration of the invention only and will vary with height above the ground, size of the luminaire 1, beam angle 10 and direction of the beam relative to the ground 40.

[0071] Schematic curve 8 shows the light intensity in the light beam 19. The light intensity is at a maximum value M at the center of the light beam 19. The light intensity decreases as the distance from the center increases. The curve shows the situation where the light intensity decreases to half of the maximum value (1 / 2M). Figure 8 This defines the full width at half maximum (FWHM) beam angle as shown.

[0072] It should be noted that the above embodiments are used to illustrate rather than limit the present invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference numerals placed between parentheses should not be construed as limiting the claims. The use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those described in the claims. The singular article before an element does not exclude the presence of a plurality of such elements.

[0073] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A lighting system (3) for providing photosynthetically stimulating artificial light to a designated target area requiring photosynthetically stimulating artificial light, the lighting system (3) comprising at least one luminaire (1) having a light source, It is characterized in that The illuminator (1) emits photosynthetically stimulating light at a narrow beam angle (FWHM) of less than or equal to 20°, the lighting system (3) comprises means for positioning the at least one illuminator at a distance of at least 20 m from the designated target area measured along the beam direction, and the illuminator (1) is adapted to emit photosynthetically stimulating light at a minimum of 140 µmol / s / m 2 The photosynthetic photon flux density illuminates the designated target area.

2. The lighting system (3) according to claim 1, in, The illuminator (1) emits photosynthetic stimulating light at a narrow beam angle (FWHM) greater than or equal to 3°.

3. The lighting system (3) according to any one of claims 1 and 2, in, The illuminator (1) has a minimum of 210 µmol / s / m 2 The designated target area is irradiated.

4. The lighting system (3) according to any one of claims 1 and 2, in, The target area is illuminated with an illumination uniformity of at least 0.

6.

5. The lighting system (3) according to any one of claims 1 and 2, in, The light source includes an LED lamp.

6. The lighting system (3) according to any one of claims 1 and 2, in, The light source includes a laser diode.

7. The lighting system (3) according to any one of claims 1 and 2, in, The illuminator (1) can be installed tiltably.

8. The lighting system (3) according to any one of claims 1 and 2, in, The light source can be tilted relative to the luminaire (1).

9. The lighting system (3) according to any one of claims 1 and 2, in, The means for positioning the at least one luminaire comprises an edge portion of a roof (5) of a stadium (6).

10. The lighting system (3) according to any one of claims 1 and 2, in, The means for positioning the at least one luminaire comprises a light pole.

11. The lighting system (3) according to any one of claims 1 and 2, in, The lighting system (3) includes a monitoring system for monitoring and estimating the need for artificial lighting over all parts of the target area to achieve acceptable growing conditions for grass.

12. The lighting system (3) according to claim 11, in, The surveillance system includes at least one camera.

13. The lighting system (3) according to any one of claims 1 and 2, in, The lighting system comprises a floodlighting system.

14. A floodlighting system for illuminating a lawn (4) of a sports stadium (6). in, The floodlighting system comprises a lighting system (3) according to any one of claims 1 to 12.

15. A method for improving plant growth conditions by exposing the plants to photosynthetic artificial light from a light source to improve the growth conditions of plants requiring light at a designated target area, It is characterized in that The method comprises providing a lighting device (1) comprising the light source, the lighting device (1) being adapted to emit the photosynthetic artificial light at a narrow beam angle (FWHM) of less than or equal to 20°, the light source being located at a distance of at least 20 m from the designated target area and having a minimum radiation intensity of 140 µmol / s / m 2 The photosynthetic photon flux density illuminates the plants in the designated target area.

16. The method according to claim 15, in, The method involves a minimum of 210 µmol / s / m 2 The designated target area is irradiated.

17. The method according to any one of claims 15 and 16, in, The target area includes grass in a stadium (6).

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