The present invention relates to a method of growing plants, wherein a system is used comprising

- supply lines, and

- a plurality of growth stations, each growth station comprising

- a location for storing a container for supporting plants, and

- a source of light; wherein said container comprises

- a support surface for supporting the plants to be grown; wherein the method comprises the steps of

- providing a container with plants,

- moving the container to a growth station,

- growing the plants supported by the container at the growth station below a source of light, and

- retrieving said container with grown plants from the location of the growth station.

Such a method of growing plants is known in the art, and is typically performed in confined spaces, such as greenhouses, sea containers, rooms of buildings etc.

Being in a confined space, the plants have to be provided with everything they need. Thus they are provided with light and water.

Water and electricity are supplied using supply lines. These add to the cost of the system, and hence increases the cost of growing the plants.

The present invention relates to a method according to the preamble in which the cost of growing plants is reduced.

To this end, a method according to the preamble is characterized in that a system is used wherein the supply lines are power lines, and the containers used for growing the plants are containers comprising a reservoir, said reservoir containing water for watering the plants while the container is stored in the system.

As no supply lines (conduits) for water have to be provided, the system is considerably cheaper to build. As there are also no conduit connections, the risk of spillage at the connection is avoided, reducing the risk of growth of algae, which saves on maintenance and thus maintenance cost. This adds to the savings in cost. Typically the reservoir will be a reservoir residing below the support surface for the plants.

In the present application, the term plant includes a seed which may or may not have germinated.

Containers will typically be moved using a shuttle (an autonomous transport vehicle), as is known in the art. The container comprises for example wheels located on tracks, and the shuttle drives the container over the tracks to and from the growth location.

According to a possible embodiment, the system comprises at each location where containers are stored a pump for extracting water from the container and supplying the plants of that container with said water in the period while the container is stored.

According to another possible embodiment, different types of plant are grown in the system, and the water in the reservoir of the container to be moved to a location of a growth station may be different depending on the type of plant in the container, e.g. with respect to its pH or nutritional content (nitrate, phosphate, minerals such as potassium, magnesium, calcium, iron etc.).

The system is for example a system used for vertical farming.

According to a favourable embodiment, the container comprises a pump for pumping water from the reservoir to the plants and the plants are watered using the pump.

This eliminates the pump from the system and reduces maintenance cost. Watering may be continuous circulation or ebb-flood operation in which the plants are periodically flooded.

According to a favourable embodiment, the container comprises at least one sensor chosen from i) a temperature sensor, ii) a pH sensor, ill) an ion sensor, iv) a Relative Humidity sensor, v) a water level sensor, and vi) a conductivity sensor for measuring the water.

The ion sensor may measure the concentration of a particular ion, such as nitrate, and output from the ion sensor may be used to dose additional ions from the further reservoir to the water, if needed. This may be determined by a control unit on the container or a central control unit of the system. Communication of sensor data (and control data) between the container and the system may be done using any means, preferably wirelessly, advantageously using an IR receiver/transmitter.

The water level sensor may be used to determine if the reservoir runs out of water or if the water level for watering the plants is within a desired range and/or for a desired duration.

According to a favourable embodiment, the container comprises a further reservoir, said further reservoir containing a liquid chosen from i) a plant nutrient solution, ii) a pH regulating solution.

Thus the plants can be provided with other factors necessary for or enhancing growth of the plants. Typically the liquid will be provided to the water in the reservoir. The container will typically comprise at least one of i) a valve connected to the pump, and ii) a further pump to dispense the liquid from the further container.

According to a favourable embodiment, the container is provided with wireless power transfer.

The wireless power transfer, typically using induction coils, avoids the need for a direct electrical connection with the container, rendering the system more reliable and thus making it cheaper to grow plants. The power may be used to power the pump(s), sensors, a control unit for controlling a sensor and/or data communication between the container and the system, etc..

According to a favourable embodiment, the reservoir comprises at a baffle device, said baffle device comprising at least one wall extending in a direction from bottom to top, said wall allowing the passage of water through at least one passage opening.

This dampens the effect of water sloshing in the container or escaping the container. The at least one wall will extend in a direction transverse to the direction of travel along the track.

According to a favourable embodiment, the reservoir is provided with a flow rate dependent valve capable of moving to a relatively closed position in case of a relatively high flow rate through the valve and a relatively open position in case of a relatively low flow rate through the valve.

Such a valve is known in the art, for example a ball valve with compression spring biased to the relatively open position or biasing the ball operating under the force of gravity to the relatively open position.

According to a favourable embodiment, the container comprises a particle filter for water used to water the plants.

Thus the pump is not affected by particles from the plants, more specifically the substrate on which the plants are grown. Preferably, drained water comprising particles is passed through said filter to the reservoir.

Finally, the present invention relates to a system comprising a plurality of layers, each layer comprising

- supply lines, and

- a plurality of growth stations, each growth station comprising

- a location for storing a container for supporting plants, and

- a source of light;, wherein the supply lines are electrical supply lines, and a container is provided with wireless power transfer and a data interface.

Such a system can be used in a method according to the invention. As no supply lines (conduits) for water have to be provided, the system is considerably cheaper to build. As there are also no conduit connections, the risk of spillage at the connection is avoided, reducing the risk of growth of algae, which saves on maintenance and thus maintenance cost. This adds to the savings in cost.

The wireless power transfer, typically using induction coils, avoids the need for a direct electrical connection with the container, rendering the system more reliable and thus making it cheaper to grow plants. The power may be used to power pump(s), sensors, a control unit for controlling a sensor and/or data communication between the container and the system, etc..

The data interface allows a user to manage the containers stored in the system, and to monitor for example temperature or relative humidity at the growth locations if the system is provided with sensors to temperature or relative humidity.

According to a favourable embodiment, the system comprises a control unit for controlling pumps at the growth stations.

Thus water can be supplied to plants at the growth stations. If the pumps are not part of the system, the system will comprise a communication device at each growth station for communicating with the container at a growth station.

The present invention will now be illustrated with reference to the drawing where

Fig. 1A shows a container stored at a growth location, and Fig.

IB shows a system used for growing plants.

Fig. 1A shows a a cross section of a container 100 stored at a growth station 195 for growing plants 190.

The container 100 is provided with wheels 101. After the container 100 is provided with plants 190, the shuttle 110 transports the container 100 through a greenhouse to a growth location 199 by driving the container 100 over the tracks 120 using its wheels 101.

The growth station 195 is provided with a climate control unit 197 and LEDs as a source of light 198 to provide the plants 190 with light while growing at the growth location 199. The LEDs are connected to supply lines 130, here power lines 130', to provide the LEDs with electricity.

The container 100 is furthermore provided with a support surface 140 on top of which plants 190 are located, and an environment sensor 102 which, in this case a temperature sensor 102.

The container 100 also comprises a reservoir 150 containing water for watering the plants 190. The reservoir 150 is located below the container 100, and is provided with a circulation pump 151. The circulation pump 151 pumps water from the reservoir 150 to the plants 190 in order to provide the plants 190 with water and support growth of the plants 190. The flow rate of the water is controlled by a flow rate dependent valve 152. At a relatively low flow rate of the water, the valve 152 is in a relatively open position, while at a relatively high flow rate, the valve 152 is in a relatively closed position. In this way, the amount of water supplied tot the plants 190 is regulated.

The composition of the water supplied to the plants 190 is monitored by the water sensor 153 before being supplied to the plants 190. If necessary, the water in the reservoir 150 is complemented with a liquid from a further reservoir 170, in order to regulate the water's nutrient composition and/or its pH. The further reservoirs 170 are connected to a pumping system 155 comprising valves 156 in order to pump the liquid to the reservoir 150.

After providing the plants 190 with water, excess water is drained, and the drained water is filtered through particle filter 154 in order to remove particles, such as particles of substrate in which the plants 190 are grown, entranced by the drained water. The filtered water is then directed back to the reservoir 150.

In order to reduce sploshing and spilling of the water when the container 100 is transported to and from the growth location 199, the reservoir 150 comprises a baffle device 160. A baffle wall 161 extends in a direction from top to bottom of the reservoir, and water can pass through a opening 162. Because of the compartmentalization of the reservoir 150, the water contained in the reservoir 150 is less likely to escape from the reservoir 150 when the container 100 is moved.

In order to power the circulation pump 151 and the pump system 155, the container 100 is provided with a wireless power transfer 157 in the form of induction coils. A control unit 158 connected to the wireless power transfer 157 allows to control data communication between the container 100 and the system 180. In this way it is for exmaple possible to transport the container 100 to an available growth location 199.

Fig. IB shows a system 180 for vertical farming comprising a plurality of layers 181, each layer 181 comprising a plurality of tracks 120, supply lines 130 and a plurality of growth locations 199. By using such a system 180, available space in a greenhouse is utilized more efficiently for the method for growing plants according to the invention since containers 100 can be stored at growth locations 199 located above each other.