Light transfer unit

Abstract

The present invention is in the field of crop cultivation, typically in a receptacle, which may be soilless or not. More in particular the present invention relates to so-called vertical farming, wherein typically artificial light is provided to growing crops. The present invention aims amongst others at reducing energy consumption.

Description

[0001] LIGHT TRANSFER UNIT

[0002] FIELD OF THE INVENTION

[0003] The present invention is in the field of crop cultivation, typically in a receptacle, which may be soilless or not. More in particular the present invention relates to so-called vertical farming, wherein typically artificial light is provided to growing crops. The present invention aims amongst others at reducing energy consumption.

[0004] RELATED APPLICATIONS

[0005] The present application claims the benefit of priority from Dutch Patent Applications NL2035568, filed on August 8, 2023, in the name of Deep Light Holding B.V., Netherlands.

[0006] The entire contents of the above-referenced application and of all priority documents as referenced in any present or future Application Data Sheet filed herewith are hereby incorporated by reference for all purposes.

[0007] BACKGROUND OF THE INVENTION

[0008] Agriculture relates amongst others to crop and livestock production, aquaculture, fisheries, and forestry, for food and non-food products. Typically small and large farms produce food products. Major agricultural products relate to foods, fibers, fuels, and raw materials. Food classes include cereals (grains), vegetables, fruits, cooking oils, meat, milk, eggs, and fungi.

[0009] Part of the food is produced as crops. Cropping systems may vary among farms, such as depending on the available resources and constraints; geography and climate of the farm; government policy; economic, social and political pressures; and the philosophy and culture of the farmer. In addition, many crops are grown in greenhouses. A greenhouse relates to a structure that allows farmers to regulate crop growth, such as through climatic conditions, such as temperature and humidity, through regulated provision of nutrients and of light, through selection of substrate, and so on. There are many different designs of greenhouses; typically they include large areas of optically transparent material, to capture light and possibly heat of the sun. The three most common transparent materials used in the roof and walls of modem greenhouses are rigid plastics made of polycarbonate, plastic films made of polyethylene or glass panes. When the interior of a greenhouse is exposed to sunlight, the internal temperature rises and shelters the plants from cold weather. The word greenhouse can be used interchangeably with the terms glasshouse and hothouse. A further development relates to so- called vertical farming.

[0010] Vertical farming relates to growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques, such as hydroponics, aquaponics, and aeroponics. Some common choices of structures to house vertical farming systems include buildings, shipping containers, tunnels, and abandoned mine shafts. An important advantage of vertical farming technologies is the increased crop yield, that comes with a smaller unit area of land requirement. Another advantage is the increased ability to cultivate a larger variety of crops. Additionally, crops are resistant to weather disruptions because of their placement indoors, meaning fewer crops are lost to extreme or unexpected weather occurrences. Because of its limited land usage, vertical farming is less disruptive to the native plants and animals, leading to further conservation of the local flora and fauna. Vertical farming technologies face economic challenges with large start-up costs compared to traditional farms. Vertical farms require large energy demands, e.g. due to the use of supplementary light provided to crops. Further, light pollution, ventilation, and water pollution may be issues.

[0011] Reference can be made to KR 2019 0078118 A, and KR 2010 0136718 A. KR 2019 0078118 A recites a plant factory system using sunlight. It includes: a light collecting unit which collects sunlight by having a first light collecting unit and a second collecting unit included in the upper open area of a cultivation building unit; a light filter unit which includes at least one light transmitting and reflecting filter receiving sunlight collected in the first light collecting unit via a first optical cable to transmit a part of the transmitted sunlight as the sunlight for illumination and reflect remaining sunlight as sunlight for power generation and thus, divides sunlight into sunlight for illumination and sunlight for power generation; an illumination unit, arranging an optical pipe connected to the optical filter unit in the cultivation room, illuminating the interior space of the cultivation room by the sunlight for illumination supplied to the inside of the optical pipe after being transmitted by the light transmitting and reflecting filter; a heat storage unit which has a heat storage room for receiving sunlight collected in the second light collecting unit via a second optical cable, has a black body for generating heat by the radiant energy of sunlight transmitted through the second optical cable in the heat storage room, and stores thermal energy by having a phase change material phase- changed by the black body in the heat storage room; and a heat exchange unit which heats the cultivation room by having a first heat exchanger arranged in the heat storage room and absorbing stored thermal energy and a second thermal exchanger arranged in the cultivation room and emitting thermal energy. KR 2010 0136718 A recites a system and a method for growing plants indoor to massively growing the plants, to increase the growth speed of the plants, and to reduce the energy consumption amount for growing the plants. The system comprises the following: a light collector collecting sunlight, and transferring the sunlight through an optical fiber bundle; a storage receiving the sunlight from the optical fiber bundle and storing after transmitting into the electrical energy; and a lighting using the collected sunlight and the electrical energy to radiate artificial light.

[0012] So, the present invention therefore relates to an improved apparatus for use in a vertical farm, which solves one or more of the above problems and drawbacks of the prior art, providing reliable results, without jeopardizing functionality and advantages. SUMMARY OF THE INVENTION

[0013] The present invention relates in a first aspect to a light transfer unit, at a first end thereof receiving and collecting light, and at another end thereof transmitting light, comprising at least one light collecting element 1 for directing collected light, which light is collected from solar / moon radiation and optional further light being available outside, to at least one light transmitting element 7 for transmitting light to at least one light releasing element, wherein the at least one light collecting element, the at least one light transmitting element, and the at least one light releasing element provide an optical path, and in the optical path, at least one optical filter 3 for providing at least one first bandwidth of light suitable for growing a crop, as the present light transfer unit is intended to support crop growth by providing light to growing crops, in particular at least one bandwidth adaptable optical filter, such as a beam splitter, and for providing at least one second bandwidth of light suitable for generating electrical power, further comprising at least one controller for balancing emitted light output and artificial light output, in combination with an artificial light input, the at least one artificial light input configured to provide artificial light in at least one third bandwidth with at least one amount. In addition to the light provided to crops, at least a part of the light that is no used for growing crops is used to convert said remaining light into electricity. As such also a (further) contribution to saving light is provided.

[0014] The present light transfer unit, also referred to as Deep Light system, provides an innovative and sustainable solution for growth-light in vertical farming, in particular to meet increasing market needs, while offering significant energy savings and environmental benefits. This system can also be beneficial for any other agricultural method that utilizes artificial growth lights, such as greenhouses, which further may be covered with solar panels. In an exemplary embodiment Deep Light collects sunlight from the external environment, transfers it to an enclosed space of vertical farms (or any space without natural light) through optical fibers, and then re-illuminates’ sunlight to desired point. In summary, the Deep Light System consists of hardware components for collecting, transmitting, and distributing sunlight indoors, along with a software component that uses Al to optimize lighting conditions for plant growth in matter of combining natural and artificial growth light. Deep Light provides complete control over natural lighting, optionally combining it with existing artificial light, such as in vertical farms. This ensures stability in the system while reducing electricity consumption. Whenever natural light is available, the usage of artificial light and, consequently, electricity may be reduced proportionally and whenever there is insufficient sunlight or it is unavailable, the present computer system ensures that e.g. a vertical farm receives the required light from artificial sources. Initial experiments have shown that, on average, the present approach can save up to 30% of energy consumption over a one-year cycle (which may be significantly higher in sunnier regions, such as Dubai). The present system is completely green and independent of external energy sources for operation. A primary market for the present system is vertical fanning, which cunently relies on artificial light for plant growth. The market estimate for growth lights in Europe is projected to reach approximately €2800 million by the end of 2023. The payback period from energy savings in a vertical farm is less than 3 years. The system can also be applied in various economic and social sectors, including hospitals, housing, and industrial plants, making it also valuable there. The present system has amongst others the following advantages: 1 : optimal light transmission, e.g. for plant growth, is achieved; 2. Sunlight usage: Utilizing the unwanted spectrum of sunlight to generate electricity (no external energy source required for system operation); 3. Control: Ability to dim sunlight to desired level; 4. Sustainability: Completely sustainable and green; 5. Constant light output: Monitor the amount of sunlight in real time and add artificial light to it when there is not enough sunlight (cloudy times), to maintain a constant light output, in terms of e.g. wavelength and intensities; 6. Optimize system: An artificial intelligence system that monitors plant growth and optimizes light profiles over time.

[0015] In a second aspect the present invention relates to a module comprising a plurality of light transfer units according to the invention, in particular 2-26units, more in particular 4-25units, even more in particular 7-24units, such as wherein the units are provided in an array.

[0016] In a third aspect the present invention relates to a vertical farm comprising at least one light module according to the invention or at least one light transfer unit according to the invention.

[0017] In a fourth aspect the present invention relates to a method of operating a vertical farm, comprising

[0018] Providing at least one light module according to the invention or at least one light transfer unit according to the invention,

[0019] Adapting collected light to a bandwidth in photosynthetic active radiation bandwidth by the at least one optical filter, transmitting adapted light in at least one third bandwidth with at least one amount in view of crops to be grown, and

[0020] Providing adapted light to growing crops.

[0021] In a fifth aspect the present invention relates to a computer program comprising instructions for operating a light transfer unit according to the invention or for operating a light module according to the invention or for carrying out the method according to the invention, the instructions, when loaded on a microprocessor or computer, causing the computer to carry out: Receiving first spectral information from the released light, the spectral information comprising an intensity and a corresponding wavelength, Comparing the released light first spectral information with crop required second spectral information, Adapting the released light to decrease a difference between first spectral wavelength intensity and second spectral wavelength intensity for the second spectral wavelengths, and providing artificial light in at least one third bandwidth with at least one amount of which the intensity difference is not fully adapted.

[0022] Therewith the present inventions solves one or more of the prior art problems without jeopardizing functionality or performance.

[0023] DETAILED DESCRIPTION OF THE INVENTION

[0024] In an exemplary embodiment the present light transfer unit comprises at least one light-to- electricity converter (5), such as a solar cell.

[0025] In an exemplary embodiment of the present light transfer unit the at least one first bandwidth is selected from bandwidth in a range of 300-800 nm, in particular from 400-700 nm.

[0026] In an exemplary embodiment of the present light transfer unit the at least one second bandwidth is selected from bandwidth in a range of 120-400 nm, in particular from 200-350 nm, and from a range of 700-3000 nm in particular from 800-2500 nm.

[0027] In an exemplary embodiment of the present light transfer unit the at least one light transmitting element is selected from an optical fiber, > , in particular an optical fiber with a diameter of 0.1-20 mm, in particular wherein a material of the optical fiber is selected from glass, polymeric materials, such as PMMA.

[0028] In an exemplary embodiment of the present light transfer unit the at least one light releasing element is selected from an optical lens and an optical fiber.

[0029] In an exemplary embodiment of the present light transfer unit the at least one light releasing element is provided in a holder, such as a frame, in particular a holder with a multitude of light releasing elements, such as 1-20 light releasing elements per meter

[0030] In an exemplary embodiment of the present light transfer unit the at least one light collecting element (1) is selected from an optical lens, a Fresnel lens, an optical concave mirror, and a beam splitter.

[0031] In an exemplary embodiment of the present light transfer unit the at least one light collecting element (1) comprises an optical focal point, which optical focal point substantially coincides with an input of the at least one light transmitting element.

[0032] In an exemplary embodiment the present light transfer unit further comprises at least one controller, in particular wherein the at least one controller is configured for controlling emitted light, in particular at least one amount thereof and at least one bandwidth thereof, and / or for controlling conversion of light into electrical power, in particular at least one amount thereof and at least one bandwidth thereof.

[0033] In an exemplary embodiment the present light transfer unit further comprises at least one controller for balancing emitted light output and artificial light output, in particular in combination with an artificial light input, the at least one artificial light input configured to provide artificial light in at least one third bandwidth with at least one amount, in particular wherein the at least one controller controls output of the artificial light source. In an exemplary embodiment the present light transfer unit comprises an light angle beam reducer configured for reducing an angle of a light beam entering the at least one light transmitting element.

[0034] In an exemplary embodiment the present light transfer unit comprises an optical separator for removing wavelengths from the optical path outside the at least one first bandwidth and outside of the at least one second bandwidth.

[0035] In an exemplary embodiment the present light transfer unit comprises a solar tracker, and an actuator for directing the unit towards the position of the sun for optimizing an amount of light received by the light transfer unit from the sun.

[0036] In an exemplary embodiment the present light transfer unit comprises at least one optical sensor, the optical sensor configured to provide output comprising intensity versus wavelength characteristics of the received light.

[0037] In an exemplary embodiment the present light transfer unit comprises a parallelization lens (2), wherein the parallelization lens is provided in the light path between the light collecting element (1) and the at least one optical filter.

[0038] In an exemplary embodiment the present light transfer unit comprises a focusing lens (4), wherein the focusing lens (4) is provided in the light path between the optical filter (3) and the at least one light-to-electricity converter (5).

[0039] SUMMARY OF THE DRAWINGS

[0040] Figs. 1-6 show exemplary embodiments and details of the present invention.

[0041] DETAILED DESCRIPTION OF THE DRAWING

[0042] In the figures:

[0043] 100 light transfer unit

[0044] 200 module with plurality of light transfer units

[0045] 1 light collecting element (main collecting lens (Fresnel plastic or glass)

[0046] 2 parallelization lens

[0047] 3 optical filter, such as beam splitter

[0048] 4 defocusing lens

[0049] 5 light-to-electricity converter (solar cell)

[0050] 6 sun-tracker

[0051] 7 light transmitting element (optical fiber)

[0052] 8 frame comprising optical distributors (light releasing element)

[0053] 9 re-emitted sunlight

[0054] Figure 1 shows an exemplary embodiment. The system consists of four parts:

[0055] A. Light collector: This section, based on geometric sections in optics physics, including concave mirrors, ordinary lenses, and Fresnel lenses, etc., concentrates sunlight at one point and directs it into the next section, i.e., optical fiber. Near the focal point, a second concentrator used to reduce the angle difference between the light beams to accommodate the optical fiber within the input angle range. The collector system also uses a filter to separate unwanted waves of sunlight such as infrared and ultraviolet. These wavelengths are used to generate the electricity required by the mechanical part. Mechanical part is installed on a base that always keeps the collector facing to the sun.

[0056] B. Light transmitter: This part is composed of optical fiber that traps light by entering one end due to the general refraction phenomenon and does not allow it to leave until the other end. The material and dimensions of this optical fiber are selected based on the volume of light collected in the first part and the length required for transmission and the amount of fiber thrown. But it generally is PMMA.

[0057] C. Reflection of light: In this part, like the first part, but with a reverse trend compared to that, the light in the optical fiber is reflected on the desired area.

[0058] D. Control system: Since sunlight is not always available (such as on cloudy days), we have designed this system as a hybrid so that it can work alongside artificial light. For this purpose, the computer part of our system adds artificial light to the required level by monitoring the amount of sunlight online, if necessary. The system consists of two parts, sensors that are placed in the path to collect data and a controller that based on the data of the sensors decides to control the volume of incoming light and, if necessary, combines it with artificial light.

[0059] Fig. 2 shows an arrangement of sun tracker and light collection units and optical fiber (front & back view).

[0060] Fig. 3 shows a light releasing element.

[0061] Fig. 4 shows a schematic composition of the light collector on the top of the building and its light releasing element inside the floors of the vertical farm

[0062] Fig. 5 shows a exemplary sample unit.

[0063] Fig. 6 shows an array of light releasing elements.

[0064] In detail:

[0065] 1. Large lens: This lens is used to collect and focus sunlight. This lens typically has a diameter of 10 to 30 cm and a focal distance of 10 to 30 cm. A Fresnel type lens typically is of PMMA plastic material. The reason for using the Fresnel lens is its economic advantage (due to thin thickness-about 2mm) and its non-breakability during handling and use. The lens focuses the light at its focal point. This lens can be of any diameter or focal length and only its coordination with the rest of the system is important.

[0066] 2. First small lens: the large lens focuses the light at its focal length. The small lens may have a diameter between 3 and 10 mm, and its focal length is obtained from the ratio equal to D / F (diameter to focal length) of the large lens. This lens is typically made of glass to withstand the heat of focused light. The light input angle is most suitable for optical fiber (unless we use lenses with a very large ratio of focal length to diameter, which makes the whole system very large and is not suitable). Since the optical fiber typically has a maximum acceptance angle of about 30 degrees, inventors limit the light to this angle before entering the optical fiber. So, inventors put a small lens with the same focal length to diameter ratio as the big lens, behind it. It means that the light waves enter the optical fiber perfectly parallel (with zero angle of entry). The advantage of reducing the entrance angle to zero is to reduce the number of light reflections inside the optical fiber and, as a result, less energy loss. This lens is placed at a distance equal to the sum of the focal lengths of the two lenses compared to the first lens.

[0067] 3. Beam splitter: A beam splitter is used to separate the appropriate wavelengths of light for plant growth (mainly visible light). This piece of glass typically with angle of 45 degree in path of concentrated light, passes part of the light and reflects the other part at an angle of 90 degrees. The light needed for the growth of the plant passes through and shines into the optical fiber, and the reflected light goes to the solar cell to generate electricity. The size of beam splitter is between 5 and 15 mm.

[0068] 4. Second small lens: since the light is already focused and parallel (like a laser beam), shining it directly on the solar cell causes it to burn. Therefore, another small lens with the same diameter as the previous small lens and a focal length corresponding to the placement distance of the solar cell is placed in its way to shine light at it at a wide angle. It means that it may of be glass and with a diameter between 3 and 10 mm.

[0069] 5. Solar cell : The IR and UV parts of the light were separated by a beam splitter and shined into this solar cell by a second small lens. This cell is mainly designed to work with these rays of light and produces electricity from it. This electricity is stored in a small battery for use in the used sun tracker. Its size may be between 5 and 10 cm.

[0070] 6. Sun Tracker is a mechanical set of engines or hydraulic jacks that finds the position of the sun in the sky based on GPS or light intensity sensors and keeps the whole set facing it. These devices exist separately (mainly produced for use in solar farms) and this system also uses them to face the sun but uses its own generated electricity to not depend on an external power source.

[0071] 7. Optical fiber: The optical fiber used is made of plastic (PMMA) and it keeps the light that entered with an angle of entry lower than its acceptance angle. The length of the optical fiber depends on the distance from the place where the light is collected to the place where it is used. Its diameter may be between 3 and 10 mm and can have an outer coating to protect against damage.

[0072] 8. light releasing element, same as ordinary LED light box. Using this part, the optical fiber is fixed above the place of use, and its light is radiated to the place of use by small plastic lenses with a specific radiation angle (usually 60 to 120 degrees). Its usual dimensions are 20 x 20 x 100 cm, and it is usually made of plastic or aluminum.

Claims

CLAIMS1. A light transfer unit comprising at least one light collecting element (1) for directing collected light to at least one light transmitting element (7) for transmitting light to at least one light releasing element, wherein the at least one light collecting element, the at least one light transmitting element, and the at least one light releasing element provide an optical path, and in the optical path, at least one optical filter (3) for providing at least one first bandwidth of light suitable for growing a crop, in particular at least one bandwidth adaptable optical filter, such as a beam splitter, and for providing at least one second bandwidth of light suitable for generating electrical power, and further comprising at least one controller for balancing emitted light output and artificial light output, in combination with an artificial light input, the at least one artificial light input configured to provide artificial light in at least one third bandwidth with at least one amount.

2. The light transfer unit according to claim 1, wherein the light transfer unit comprises at least one light-to-electricity converter (5), such as a solar cell.

3. The light transfer unit according to any of claims 1-2, wherein the at least one first bandwidth is selected from bandwidth in a range of 300-800 nm, in particular from 400- 700 nm, and / or wherein the at least one second bandwidth is selected from bandwidth in a range of 120- 400 nm, in particular from 200-350 nm, and from a range of 700-3000 nm in particular from 800-2500 nm,.

4. The light transfer unit according to any of claims 1-3, wherein the at least one light transmitting element is selected from an optical fiber, in particular an optical fiber with a diameter of 0.1-20 mm, in particular wherein a material of the optical fiber is selected from glass, polymeric materials, such as PMMA,5. The light transfer unit according to any of claims 1 -4, wherein the at least one light releasing element is selected from an optical lens and an optical fiber, and / or wherein the at least one light releasing element is provided in a holder, such as a frame, in particular a holder with a multitude of light releasing elements, such as 1-20 light releasing elements per meter.

6. The light transfer unit according to any of claims 1-5, wherein the at least one light collecting element (1) is selected from an optical lens, a Fresnel lens, an optical concave mirror, and a beam splitter, and / or wherein the at least one light collecting element (1) comprises an optical focal point, which optical focal point substantially coincides with an input of the at least one light transmitting element.

7. The light transfer unit according to any of claims 1-6, further comprising at least one controller, in particular wherein the at least one controller is configured for controlling emitted light, in particular at least one amount thereof and at least one bandwidth thereof, and / or for controlling conversion of light into electrical power, in particular at least one amount thereof and at least one bandwidth thereof.

8. The light transfer unit according to any of claims 1-7, wherein the at least one controller controls output of the artificial light source.

9. The light transfer unit according to any of claims 1-8, comprising a light angle beam reducer configured for reducing an angle of a light beam entering the at least one light transmitting element.

10. The light transfer unit according to any of claims 1-9, comprising an optical separator for removing wavelengths from the optical path outside the at least one first bandwidth and outside of the at least one second bandwidth.

11. The light transfer unit according to any of claims 1-10, comprising a solar tracker, and an actuator for directing the unit towards the position of the sun for optimizing an amount of light received by the light transfer unit from the sun.

12. The light transfer unit according to any of claims 1-11, comprising at least one optical sensor, the optical sensor configured to provide output comprising intensity versus wavelength characteristics of the received light.

13. The light transfer unit according to any of claims 1-12, comprising a parallelization lens (2), wherein the parallelization lens is provided in the light path between the light collecting element (1) and the at least one optical filter.

14. The light transfer unit according to any of claims 1-12, comprising a focusing lens (4), wherein the focusing lens (4) is provided in the light path between the optical filter (3) and the at least one light-to-electricity converter (5).

15. A module (200) comprising a plurality of light transfer units according to any of claims 1- 14, in particular 2-26units, more in particular 4-25units, even more in particular 7-24units, such as wherein the units are provided in an array.

16. A vertical farm comprising at least one light module according to claim 15 or at least one light transfer unit according to any of claims 1-14.

17. A method of operating a vertical farm, comprisingProviding at least one light module according to claim 15 or at least one light transfer unit according to any of claims 1-14,Adapting collected light bandwidth to a photosynthetic active radiation bandwidth by the at least one optical filter, transmitting adapted light in at least one third bandwidth with at least one amount in view of crops to be grown, andProviding adapted light to growing crops.

18. A computer program comprising instructions for operating a light transfer unit according to any of claims 1-14 or for operating a light module according to any of claims 15 or for carrying out the method according to claim 17, the instructions, when loaded on a microprocessor or computer, causing the computer to carry out: Receiving first spectral information from the released light, the spectral information comprising an intensity and a corresponding wavelength,Comparing the released light first spectral information with crop required second spectral information,Adapting the released light to decrease a difference between first spectral wavelength intensity and second spectral wavelength intensity for the second spectral wavelengths, and providing artificial light in at least one third bandwidth with at least one amount of which the intensity difference is not fully adapted.

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