Vertical farm

Abstract

The system relates to a vertical farm having culture units (1) and a lighting system. The lighting system comprises at least one module (2) for collecting a total solar irradiance (3) and has an arrangement for distributing (4) the total power output in power sub-units to the culture units (1).

Description

[0001] Vertical farm

[0002] Description

[0003] The invention relates to a vertical farm with culture units having a lighting system.

[0004] Vertical farming is a relatively new technology. In 1964, a 41-meter-high tower greenhouse designed by inventor and mechanical engineer Othmar Ruthner was exhibited at the International Garden Show in Vienna. Subsequently, more tower greenhouses were built: in 1965, a 23-meter-high tower was built in the research garden of Bayer-Werke AG in Leverkusen; in the same year, the 18-meter-high tower was built by nursery owner Ernst Haller in Rüfenach, Switzerland; and finally, a 54-meter-high tower in Chorzöw, Poland. Othmar Ruthner obtained patent AT243553B for his "greenhouse with a tower-like structure" in 1963.

[0005] Currently, none of these buildings exist anymore. The reasons why vertical farming was not yet able to establish itself alongside traditional, open-air horizontal farming at this early stage were the high costs of building construction, high energy costs, and structural problems; for example, the tower in Chorzow was decommissioned due to the reduced light transmission of its polyester outer skin.

[0006] However, the basic idea of ​​vertical farming remains, as it offers numerous advantages over conventional open-air farming. Vertical farming enables very high productivity relative to the area cultivated.

[0007] In addition, this cultivation technique is significantly more cost-effective than conventional open-field plant cultivation. The reasons for this are manifold. These include, for example, the significantly reduced water requirement, the ability to precisely adjust the dosage of plant nutrients to the plant's needs, the significantly reduced use of pesticides, some of which can even be completely eliminated, the reduction in transport distances, and the largely independent dependence on weather conditions, to name just the most important factors.

[0008] These advantages not only make vertical farming economically attractive, they also contribute to reducing environmental impact and helping to meet the ever-increasing demand for food.

[0009] There are now companies operating farms in the form of vertical agriculture. Many of the problems that affected the original tower greenhouses have been eliminated through new concepts and technologies. For example, current detailed solutions for use in the controlled environment of vertical plant production are being developed in

[0010] EP 3768071 B1 and WO 2019 / 183244 respectively.

[0011] The ambitious concept of a "tower-like structure" was largely abandoned because the towers' enormous height would have resulted in very unfavorable temperature and humidity distributions. In addition to reducing building height and the associated expansion of the floor space, modern farm buildings generally also dispense with a transparent outer shell made of glass or transparent plastics. This primarily counteracts excessive heating of the farm buildings and prevents overheating and radiation damage to the plants.

[0012] Furthermore, an outer shell made of glass or plastic provides insufficient insulation in colder outdoor temperatures, necessitating expensive heating under these conditions. However, the design of a vertical farm as a predominantly enclosed building without direct access to daylight means that the crops must be artificially illuminated.

[0013] This results in certain advantages for plant cultivation, as the artificially generated light can be very precisely adapted to the needs of the plants in terms of both quantity and spectral composition.

[0014] The main disadvantage of these artificial lighting systems, however, is the very high energy costs associated with supplying the plants entirely with artificial light. Despite the low energy requirements of LED lights and the narrowing of the emitted light to the photosynthetically active parts of the spectrum, the costs of artificial lighting are so high that the systems are often marginally economical to operate. The use of photovoltaic systems to reduce energy costs is often not possible due to limited space capacity. Furthermore, the efficiency of such systems is relatively low, and the investment costs are very high.

[0015] Currently, lettuce or herbs are mostly cultivated in vertical farms, as these crops thrive particularly well under the conditions of vertical cultivation in closed culture spaces, can survive with relatively little light, and can be marketed with good margins.

[0016] Crucial to the future food security of a constantly growing population, however, are crops from the grass family (Poaceae / Gramineae), such as corn, rice, and wheat. However, these species of this important family of crops require significantly more light for their growth. Currently, they are not cultivated in vertical farms with exclusively artificial lighting. The object of the invention is to provide a vertical farm that excels, in particular, in the areas of energy efficiency and productivity in crop production. The innovative vertical farm is intended to be characterized by low energy consumption and contribute to more sustainable agricultural practices. At the same time, high production output is to be ensured and harvest efficiency is to be increased. The vertical farm according to the invention is intended to contribute to resource conservation.The invention is intended to be environmentally friendly while simultaneously optimizing the use of existing resources. The invention is intended to be applicable to the cultivation of a wide variety of plant species.

[0017] This object is achieved according to the invention with a vertical farm according to the main claim and a subordinate use claim. Preferred variants and features can be found in the subclaims, the description, and the drawings.

[0018] It is known that species-specific plants have different minimum light requirements for healthy growth. Excessive light levels cannot be used photosynthetically. Above a certain upper limit, which is defined differently for each species, excessive light levels can even lead to plant damage.

[0019] The light requirement of a plant species is usually described by the so-called daylight integral (DLI). The DLI describes how many moles of photons from the photosynthetically active radiation range between 400 and 700 nm reach an area of ​​one square meter in 24 hours.

[0020] With DLI values ​​of approximately 10 to 16 (10 to 16 mol photons / 24 h / m 2 Plant / leaf area), culinary herbs represent the group of commercially cultivated higher plants with the lowest light requirements. With DLI values ​​of 20 to 35 (20 to 35 mol photons / 24 h / m 2 Plant / leaf area), for example, tomatoes or the representatives of the Poaceae / Gramineae, such as maize, rice and wheat, mark the upper range of the light requirements of commercially cultivated higher plants.

[0021] In Central Europe, the DLI of the amount of light radiated by the sun varies greatly depending on latitude and season (position of the sun, day length), and cloud cover. In summer, average DLI values ​​of approximately 50 to 70 (50 to 70 mol photons / 24 h / m 2 Earth's surface). In Southern Europe, DLI values ​​rise to approximately 120 (120 mol photons / 24 h / m2 Earth's surface).

[0022] From these measured values ​​it can be seen that by using modules for collecting a total amount of daylight and an arrangement for distributing the total amount of light into partial amounts among the cultivation units, it is possible to supply an area of ​​cultivation units with a sufficient amount of light that exceeds the area of ​​the modules for collecting a total amount of daylight by at least twice the area (e.g. tomatoes DLI 30, solar radiation Central Europe DLI 60) up to a maximum of twelve times the area (culinary herbs DL1 10, solar radiation Southern Europe DL1 120).

[0023] In addition to the varying light requirements of each cultivated plant species, it is also known that plants have species-specific requirements regarding the spectral composition of light. It is often the case that the spectral ranges of light are used differently in the respective growth phases of the plant. These specific plant physiological requirements can also be optimally taken into account by appropriate control and regulation systems in a vertical farm. Due to the diverse parameters, such as the light requirements of the cultivated species, the location of the system, the influences of the season and weather conditions, to name just the most important, the specific design of a vertical farm operated predominantly with daylight must be determined individually for each system.

[0024] In a preferred embodiment, the modules are arranged on the roof and / or on the side walls of the vertical farm to collect a total amount of daylight.

[0025] Starting from these modules, an arrangement of light-guiding elements must be set up to direct the collected daylight in the closed cultivation space of the vertical farm to the cultivation units.

[0026] In a preferred embodiment, these light-guiding elements consist of a light-guiding tube and / or a light-guiding fiber bundle.

[0027] Prismatic elements are arranged to spectrally distribute the collected daylight.

[0028] Alternatively or additionally, spectrally selective optical filters, which function as beam splitters, for example, can also be used.

[0029] Coated mirrors that reflect spectrally selectively or optical gratings can also be used.

[0030] These devices allow the separated spectral components to be used for various purposes. Reflective elements are required to direct the collected daylight in a desired direction and / or to focus it more strongly. In a preferred embodiment, these reflective elements are designed as concave mirrors.

[0031] An arrangement for regulating the distribution of the collected daylight ensures a homogeneous distribution of the amount of daylight in the horizontal and vertical extent of the cultivation levels.

[0032] In a preferred embodiment, this control can be achieved via the cross-sections of the light guide elements. Control is achieved by using suitable sensors to detect the outcoupled light and suitable actuators to adjust the distributed and penetrated light.

[0033] The portions of the energy from the coupled daylight that are selectively separated by the above-mentioned elements for the spectral splitting of daylight can be converted into electrical energy by the arrangement of downstream photovoltaic cells. The electrical energy thus generated can be used to directly power the elements for generating artificial light, preferably LEDs. Alternatively, the electrical energy can also be stored in a suitable medium. This energy serves as a buffer to cover periods with low irradiation.

[0034] Daylight or to bridge the darkness at night. In a preferred embodiment, this energy storage device consists of a lithium iron phosphate battery.

[0035] Furthermore, the specified lighting system is configured to include elements for generating artificial light. This artificial light is generated in the physiological quantity and quality required for photosynthesis either in close proximity to the culture units and / or guided to the culture units via an array of light-guiding elements. This artificial light, preferably generated via LEDs, is either guided to the cultures via fiber optic bundles or generated directly above the cultures.

[0036] The spectral adjustment of daylight and / or the light generated by the elements used to generate artificial light is achieved by arranging a control device. This control device stores not only the optimal spectral composition of the light to be coupled out, but also the optimal exposure times and exposure doses, tailored to the respective cultivated crop species.

[0037] The devices described in the preceding description ensure that the total power of the collected daylight is divided into partial powers in equal parts.

[0038] This quantitative, homogeneous distribution is necessary because the cultivation areas of the cultivation units each have the same area. This allocation is essential in order to be able to functionally dimension the specific design of the lighting system of a vertical farm according to its geographical location.

[0039] To eliminate the negative effects of direct daylight, e.g., through transparent glass or plastic surfaces, the roof and side walls of a building suitable for vertical farming must be largely opaque. In a preferred embodiment, the roof and walls are constructed using standard elements for sandwich systems established in hall construction. The modules for collecting the total amount of incoming daylight are integrated into these elements. Further features and advantages of the invention can be found in the accompanying figures.

[0040] List of reference symbols

[0041] 1. Cultural units

[0042] 2nd module

[0043] 3. Daylight

[0044] 4. Order for distribution

[0045] 5. Light guide elements

[0046] 6. prismatic elements

[0047] 7. reflective elements

[0048] 8. Distribution control facility

[0049] 9. Device for converting and storing daylight energy

[0050] 10. Elements for generating artificial light

[0051] 11. Control device

[0052] 12. opaque roof

[0053] 13. Opaque walls (13)

[0054] 14. coupled daylight

[0055] 14a optical fiber with coupled daylight

[0056] 15. distributed daylight

[0057] 15a light-conducting fiber with distributed daylight

[0058] 16. Penetrated daylight

[0059] 16a optical fiber with continued daylight

[0060] 17. extracted daylight

[0061] 18. vertical light-conducting tube

[0062] 19. horizontal light-conducting tube

[0063] 20. partially transparent mirror 21. partially transparent material

[0064] 22. Bundle of optical fibers

[0065] 23. Collector concave mirror

[0066] 24. Deflecting concave mirror

[0067] 25. red and blue part of daylight for plant illumination

[0068] 26. green part of daylight I. beam splitter (filter) permeable to green light

[0069] 28. Beam splitter (filter) that transmits red and blue light

[0070] 29. Photovoltaic cell

[0071] 30. incident light

[0072] 31. reflected light

[0073] 32. partially translucent material

[0074] 33. scattering partially translucent material

[0075] 34. Skylight

[0076] Fig. 1 schematically shows a vertical farm with a lighting system according to the invention. In the illustrated embodiment, the incident daylight 3 is collected by the modules 2 mounted on the opaque side wall 13 and / or on the opaque roof 12.

[0077] The daylight 3 is guided by the light guide elements 5 to the cultivation units 1. The light guide elements 5 can be designed, for example, as a light pipe and / or as a fiber optic bundle. In the embodiments shown, both natural light and natural light that has been spectrally modified, or artificially generated light, can be guided throughout the entire lighting system. A distribution arrangement 4 determines how the total power of incident daylight 3 is divided into the partial powers to be distributed. Via prismatic elements 6 and / or reflective elements 7, the light can be modified in its spectral composition according to the needs of the respective cultivated crops. By means of a device for regulating the

[0078] Distribution 8 and by means of a control device 11, it is determined which partial powers of the radiated light in which ranges of the spectrum are guided via the further light guide elements 5 to the culture units 1 and which partial powers or which spectral ranges of the daylight 3 flow into the device 9 for converting and storing daylight energy. The energy stored in this device 9 can, in times of insufficient daylight or at night, be converted back into artificial light in the elements for generating artificial light 10, which in its spectral

[0079] Composition specifically tailored to the respective crop.

[0080] Fig.2 shows a preferred embodiment of the light guide elements 5 of the lighting system as a light-guiding tube system.

[0081] The incoming daylight 14 is transmitted vertically via a vertical light-guiding tube 18. At the height of the respective cultivation levels of the vertical farm, the incoming daylight 14 or the penetrated daylight 16 is divided via semi-transparent mirrors 20. At each level of the tube system, the distributed daylight 15 is guided into the horizontal light-guiding tubes 19. The distributed daylight 15 is distributed homogeneously as outgoing daylight 17 across the cultivation units on all levels of the vertical farm via a surface made of semi-transparent material 21.

[0082] Fig. 3 shows a preferred embodiment of the light-guiding elements 5 of the lighting system in the form of light-guiding fiber bundles. The coupled-in daylight 14 is transmitted vertically via bundles of light-guiding fibers (22). At the height of the respective cultivation level of the vertical farm, individual fibers branch off from the bundles of light-guiding fibers (22) as light-guiding fibers with distributed daylight 15a. The remaining light-guiding fibers with coupled-in daylight 14a continue downwards as light-guiding fibers with further daylight 16a to the next distribution level. The daylight 17 is coupled out directly via the ends of the light-guiding fibers with further daylight 15a.

[0083] Figs. 4a, 4b and 4c show preferred embodiments of the modules 2 in their function as coupling structures.

[0084] Figs. 4a and 4b show modules 2 that capture daylight 3 incident from different directions through collector concave mirrors 23 and project it onto a deflecting concave mirror 24. The deflecting concave mirror 24 then directs a concentrated light beam through an opening at the lower pole of the collector mirror 23 into a vertical light-conducting tube 18 (Fig. 4a) or, alternatively, onto a bundle of light-conducting fibers 22 (Fig. 4b).

[0085] In a further embodiment, the collector concave mirror 23 and the deflecting concave mirror 24 connected to it are configured so that their orientation can be adjusted by suitable devices. This makes them suitable for following the daily course of the sun's trajectory. Furthermore, their positioning can be adapted to the seasonal variations in the position of the sun.

[0086] Fig. 4c shows an alternative embodiment of modules 2 as skylight domes 34. Due to their curvature, the skylight domes 34 are capable of absorbing daylight 3 and focusing it into a vertical light-guiding tube 18 or, alternatively, onto a bundle of light-guiding fibers 22. The geometry of the dome shape of the skylight domes 34 can be adapted to the geographical conditions at the location of the vertical farm. The coupling of daylight 3 into the various design variants of the light-guiding elements 5 is freely selectable. The illustration in Fig. 4c is exemplary. In a further variant, the modules (2) for collecting daylight can also be designed in the form of Fresnel lenses.

[0087] Figures 5a and 5b show two preferred embodiments for the spectral division and use of daylight.

[0088] In Fig. 5a, an incident light beam 30 strikes a beam splitter 26 that is transparent to the green components of daylight. This photosynthetically only slightly effective portion of the daylight spectrum then strikes a photovoltaic cell

[0089] 29 and is converted there into electrical energy. This electrical energy can then be stored in a suitable medium as needed, or it can be used directly to generate artificial light, preferably via LEDs that emit in the blue and red spectral range. The red and blue components of daylight 25 are used directly to illuminate the plants.

[0090] An alternative design variant is shown in Fig. 5b. Here, an incident light beam hits

[0091] 30 to a beam splitter 28 that transmits red and blue light. The green portion of daylight 26, which has only a minimal photosynthetic effect, is reflected and reaches a photovoltaic cell 29. According to the embodiment in Fig. 4a, the electrical energy is then stored in a suitable medium as needed, or it is used directly to power LEDs. Accordingly, in this embodiment, the red and blue portions of daylight are used to illuminate the plants 25. Figs. 6a and 6b show two different output variants of the light guide system.

[0092] In Fig. 6a, an incident light beam 30 hits a semi-transparent material 32. This causes the outcoupled light to reach the culture plane in a more concentrated manner. In Fig. 6a, an incident light beam 30 hits a semi-transparent material 33 with scattering elements. This causes the outcoupled light to reach the culture plane in a diffused manner. This arrangement is particularly suitable for light emerging directly from the ends of glass fibers.

Claims

Claims 1. Vertical farm with culture units (1), characterized in that the vertical farm has a lighting system with at least one module (2) for collecting a total output of incident daylight (3) and an arrangement for distributing (4) the total output in partial outputs to the culture units (1).

2. Vertical farm according to claim 1, characterized in that the arrangement comprises light guide elements (5).

3. Vertical farm according to claim 1 or 2, characterized in that the arrangement comprises prismatic elements (6).

4. Vertical farm according to claim 1 to 3, characterized in that the arrangement comprises filters (27, 28).

5. Vertical farm according to claim 1 to 4, characterized in that the arrangement comprises coated mirrors (20).

6. Vertical farm according to one of claims 1 to 5, characterized in that the arrangement comprises reflective elements (7).

7. Vertical farm according to one of claims 1 to 6, characterized in that the arrangement has a device (8) for controlling the distribution via sensors and actuators.

8. Vertical farm according to one of claims 1 to 7, characterized in that the arrangement comprises a device (9) for converting and storing energy from daylight.

9. Vertical farm according to one of claims 1 to 8, characterized in that the lighting system comprises elements (10) for generating artificial light.

10. Vertical farm according to one of claims 1 to 9, characterized in that the arrangement comprises a control device (11) for spectral adjustment of the daylight.

11. Vertical farm according to one of claims 1 to 10, characterized in that the division of the total output into partial outputs to each culture unit (1) in equal parts.

12. Vertical farm according to one of claims 1 to 11, characterized in that the culture units (1) have the same cultivation areas.

13. Vertical farm according to one of claims 1 to 12, characterized in that daylight (5) only enters the farm via the modules (2).

14. Use of a lighting system with at least one Module (2) for collecting daylight (5) and an arrangement for distributing the daylight (5) in a vertical farm.

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