The present invention relates to an improved farming system. In particular, the present invention relates to a farming system using electric machinery, preferably powered and/or charged by an electricity supply network.

Present methods of tilling the soil and carrying out other field work by fossil fuel powered tractors have evolved over the past 80 years. However, these methods have many drawbacks and are unsustainable.

Tractors are expensive to buy and operate, are often unreliable and require a skilled driver. One of the biggest problems is that, in common with road vehicles, tractors are powered by a finite resource, liquid fossil fuel. This fuel is decreasing in supply, and resources will eventually expire either through depletion and/or geo-political events. Tractors also emit large amounts of carbon dioxide (C0 ₂ ), thus contributing to climate change.

It has been suggested that one way to reduce carbon dioxide emissions would be to introduce hydrogen powered vehicles. However, these vehicles are currently not readily available and not reliable. Furthermore, direct electric transmission is currently far more efficient (by a factor of two or more) than the production, transportation and storage of hydrogen and its conversion in fuel cells to produce electricity.

Road vehicle manufacturers are developing electric vehicles with batteries that are charged overnight or at recharge points from grid electricity. However, there are still problems associated with these vehicles, for example, with providing sufficient range whilst keeping purchase costs, running costs and vehicle weight down.

For farm tractors, as a certain amount of weight is needed to aid traction. Therefore, vehicle weight is not a big problem. However, a battery which is able to power a tractor for a full day of work would be very big and expensive. A high depth of discharge is bad for battery life, so running a battery right until it is flat would not be good practice. Finally, it is not possible with farm work to keep returning a tractor to a recharging point throughout the day for the battery to recharge. Therefore, it is not possible to run a tractor using the same principles as electric road vehicles. It is an object of the present invention to address these and other disadvantages associated with the prior art.

According to a first aspect of the present invention, there is provided a farming system comprising a vehicle, and a power supply network;

the vehicle being electrically operated; and

the power supply network being adapted to supply power to the vehicle;

wherein the power supply network is remote from the vehicle. Preferably, the vehicle is an agricultural machine or vehicle. Preferably, the vehicle is a self-propelled vehicle. Preferably, the agricultural machine or vehicle is a tractor. Alternatively, the agricultural machine or vehicle may be a combined harvester, crop sprayer or other similar machine or vehicle. The vehicle may be operable to tow or operate any suitable farming apparatus, for example a plough, harvester or the like. The apparatus is preferably attached to the tractor by means of a drawbar or hitch system.

Preferably, the vehicle is battery operated.

Preferably, the power supply network comprises an electricity supply. Preferably, the electricity supply extends from a base station to points around a farmstead.

Preferably, the base station is a farm building, for example a barn.

Alternatively, the base station may be a mains electricity supply.

Preferably, the power supply network comprises an electrically conductive cable, or cables. The cable or cables may be located underground or above-ground.

In the case where the cable or cables are located underground, the power supply network preferably comprises a plurality of electrical 'hook-up' points. The 'hook-up' points are preferably located at ground level or above ground level. In the case where the cable or cables are located above-ground, the cables are preferably in the form of over-head lines. In this case, the over-head lines may be located along a track similar to a railway track. Preferably, the farming system further comprises a battery exchange vehicle.

Preferably, the battery exchange vehicle is operable to facilitate removal of a discharged battery from the vehicle and replacement with a charged battery. Preferably, the battery exchange vehicle is in electrical contact with the power supply network. This may be by way of trolley-poles extending to the over-head lines or the electrical 'hook-ups'.

Preferably, the battery exchange vehicle is operable to hold two or more batteries.

Preferably, the battery exchange vehicle comprises battery exchange means operable to exchange a discharged battery from the vehicle with a charged battery.

Alternatively, the battery exchange vehicle is operable to facilitate charging of a discharged battery within the vehicle by making a link between the vehicle and the power supply network.

Preferably, the vehicle comprises transmitting means. Preferably, the battery exchange vehicle comprises receiving means.

Preferably, the transmitting means of the vehicle is operable transmit a location signal to the receiving means of the battery exchange vehicle. Preferably, the transmitting means is operable transmit the location signal to the receiving means upon detection of a predetermined discharge level of the battery powering the vehicle.

Preferably, the battery exchange vehicle is operable to move to a location on the power supply network that is closest to the vehicle upon receipt of the location signal from the vehicle transmitting means.

Preferably, the battery exchange vehicle is autonomous. According to a second aspect of the invention, there is provided a battery exchange vehicle operable to exchange a discharged vehicle battery in a vehicle with a charged vehicle battery, the battery exchange vehicle comprising battery storage means and battery exchange means operable to move a battery from the battery storage means and install the said battery into a vehicle.

Preferably, the battery exchange means is also operable to remove a battery from the vehicle and move it into the battery storage means.

Preferably, the battery storage means comprises space operable to store two or more batteries.

The battery exchange vehicle may be self-propelled, or may be towed by another vehicle, or may be operable to be mounted onto another vehicle. The word 'vehicle' in the term 'battery exchange vehicle' is used herein to define the ability of the battery exchange vehicle to facilitate the storage, transportation and exchange of vehicle batteries. Preferably, the battery storage means further comprises battery charging means. The battery charging means may be connected to the power supply network of the first aspect of the invention.

According to a third aspect of the present invention, there is provided a method of supplying power to an agricultural machine or vehicle; the method comprising the steps of:

a) monitoring a discharge level of a battery in the agricultural machine or vehicle;

b) on detecting a predetermined discharge level being reached in the battery, transmitting a signal to a battery exchange means; and

c) exchanging the discharged battery with a charged battery from the battery exchange means.

The invention extends to a battery exchange vehicle operable for use in the farming system of the first aspect of the invention. In order to illustrate the invention more clearly, embodiments of the present invention will now be described, by way of example only, in the following description and with reference to the accompanying drawings, in which: Figure 1 shows a schematic, side view of an electric tractor and a battery exchange vehicle of a farming system according to a first embodiment of the present invention;

Figure 2 shows a schematic, side view of the battery exchange vehicle of Figure 1 ; and

Figure 3 shows a schematic, plan view of an electric farming system according to a second embodiment of the present invention.

Throughout the following description, like reference numerals are used to refer to like features in the different embodiments of the invention.

Referring to Figures 1 and 2, a first embodiment of an electric farming system 2 is shown. The electric farming system 2 comprises an electric tractor 4 and a battery exchange vehicle 6.

The electric tractor 4 comprises a known kind of tractor having an electric, battery- powered motor.

The electric farming system further comprises a power supply network. The power supply network comprises a power supply and a track.

The track preferably connects a base station 12, for example a farm building, with a working position of the electric tractor 4. The track may connect the base station 12 with a plurality of different working positions, for example a number of different fields within a farm.

The track in the present embodiment is a path defined by an over-head electricity line 14. The over-head electricity line 14 comprises the power supply. The battery exchange vehicle 6 comprises electricity pick-up means 16 to collect electricity from the supply line 14. The pick-up means 16 in the present example comprise trolley poles. The battery exchange vehicle 6 comprises a battery store 8 and a battery charging means (not shown). The battery store 8 is operable to store at least two batteries. The battery exchange vehicle 6 comprises battery charging means (not shown) for charging any batteries present in the battery store 8. The battery charging means are operable to charge the batteries using power drawn from the supply line 14. The battery exchange vehicle 6 also has battery exchange means 10 for connection to the electric tractor 4.

The battery exchange vehicle 6 is operable to move autonomously along the track. The vehicle 6 does, therefore, not need a driver and has automatic control means so that it moves automatically to a position where it is available to the tractor 4. The battery exchange vehicle 6 is propelled by an electric motor which draws electricity from the supply line 14.

The tractor 4 comprises a transmitter (not shown) which is operable to transmit a location signal to the battery exchange vehicle 6, such that the battery exchange vehicle 6 can move along the track to the most accessible position for the tractor 4.

Alternatively, a tractor 4 user may input a desired destination into the battery exchange vehicle 6.

The electric tractor 4, or other self-propelled farm machine, is driven by electric motors. The electric motors are powered by the electric charge stored in the battery 18. Implements or harvesting machines 20, which are adapted to be pulled behind the tractor 4, may have electric motors drawing electricity from the battery through a cable from the tractor 4. This system would operate in the same way as usual in the case of towed machinery.

The battery, being the power source for the tractor 4, is operable to hold sufficient charge to power the tractor 4 for several hours. Tractors 4, and other agricultural vehicles and machinery, usually work to a set pattern up and down a field, moving along a distance equal to the width of the implement being used after each pass. Therefore, the battery is operable to hold sufficient charge for the tractor 4 to make a specified number of passes in a field.

The battery exchange vehicle 6 comprises a battery exchange mechanism 10. The battery exchange mechanism 10 is operable to interact with the battery exchange vehicle 6 and tractor 4. In particular, the battery exchange mechanism 10 is operable to interact with the battery store 8 and battery charging means of the battery exchange vehicle 6 and the battery housing (not shown) of the tractor 4. the battery exchange vehicle 6 is operable to move discharged batteries from the tractor 4 to the battery store 8, and to move charged batteries from the battery store 8 to the tractor 4.

Alternatively, the battery exchange mechanism 10 may be mounted on the tractor 4.

The battery exchange mechanism 10 comprises two forks. Preferably, the two forks are similar to those on forklift trucks. The forks are operable to enter slots (not shown) mounted above or below each battery, in a battery housing. The forks are operable to move in both substantially horizontal and substantially vertical directions to enable discharged batteries to be moved from the tractor 4 to the battery store 8, and for charged batteries to be lifted in to the tractor 4 from the battery store 8.

In alternative embodiments, the battery exchange mechanism 10 may comprise any other suitable mechanism, for example a crane.

In alternative embodiments, the track may be a more defined feature on the ground, for example a rubberised or hard-surface path, or a rail similar to a railway track. In these alternative embodiments, the track itself may be electrified, or another suitable electricity supply method may be employed.

The vehicle may run on rubber tyres such that no earth connection is required, or may have metal wheels running on light rails on the track. In the case where the vehicle running on metal wheels, only one overhead wire would be needed as one rail could act as earth.

In use, when a battery being used by the electric tractor 4 has reached an optimum level of discharge, the tractor 4 transmits a signal to the battery exchange vehicle 6 instructing it to move to the closest position along the track to the tractor 4. The tractor 4 is then moved into alignment with the battery exchange vehicle 6. An automatic battery exchange sequence would then begin.

In the automatic battery exchange sequence, the battery exchange mechanism 10 is operable to remove a discharged battery from the tractor 4. The discharged battery would be placed into an empty space in the battery store 8 of the battery exchange vehicle 6. The discharged battery would then begin to be charged by the battery charging means drawing power from the supply line 14. The battery exchange vehicle 6 would then move along the track by a predetermined distance, such that a charged battery in the battery store 8 of the vehicle is brought into alignment opposite the tractor 4. The charged battery would be placed on the tractor 4 by the battery exchange mechanism 10. In this way the tractor 4 can be kept working for long hours.

Alternatively, instead of the battery exchange sequence being automatic, it could be controlled by the tractor driver. In this case, and if the battery exchange mechanism 10 is mounted on the tractor 4, the tractor 4 would be provided with a small permanent battery to power the exchange mechanism 10 and to power the tractor 4 to enable it to move the short distance from alignment with the discharged battery into alignment with the charged battery.

To keep the battery exchange vehicle 6 balanced, as a battery is moved into or out of a space in the battery store 8 of the vehicle 6, one of the other batteries, or the other battery, in the battery store 8 may be operable to move in the opposite direction on its exchange mechanism 10.

Several tractors 4 can be served by the same battery exchange vehicle, and batteries can be exchanged on both sides of the vehicle 6 to allow for ease of operation.

Electric powered tractors would be ideal for unmanned operation using GPS guidance and remote monitoring. Machines such as harvesters could have a separate electric motor drive instead of being driven from the tractor by shafts, chains, belts or hydraulics, and would be able to have variable speeds, independent of the tractor motor speed. Similarly, combine harvesters could have separate motors driving the drum, header, traction wheels and the like. The electricity supply line could be used to supply power to equipment such as irrigation pumps and transport vehicles. Referring now to Figure 3, in a second embodiment of an electric farming system 200, buried cables 202 are used to carry the electricity from the farmstead instead of overhead wires. The cable 202 comprises electrical connective posts 204 which extend from the cable 202 to emerge above ground level. The posts 204 are arranged at suitable intervals, for example, every 100 metres.

The battery exchange vehicle 6 in the second embodiment of the invention is operable to draw power from the underground cable 202 to charge the batteries held in the battery store 8 while connected to a suitable connective post 204. The battery exchange vehicle 6 would then draw power from a charged battery to travel to where a tractor 4 needed a battery exchange. The vehicle 6 would be operable to locate its position and determine where to move to to reach the next connective post 204 or tractor 4 by using a global positioning system (GPS) and/or telemetry from signals received from the tractor 4 and/or the connective posts 204. Switches (not shown) on the connective posts 204 would ensure that only the posts 204 being used, that is, only those posts 204 that are in contact with a battery exchange vehicle 6, would be live.

In yet a further alternative embodiment of the present invention, the power supply network comprises power connection points, or sockets, located at strategic positions leading from the base station, for example at the entrance to each field. In this embodiment, the word 'vehicle' in the term battery exchange vehicle is used to define the ability of the battery exchange vehicle to facilitate the carriage and storage of batteries. The term is not used exclusively to define the battery exchange vehicle as having a self-propelling ability. In the present embodiment, the battery exchange vehicle may also be considered to be a battery exchange and charging platform.

The battery exchange vehicle in this embodiment has no permanent connection to the power supply network, and is preferably mounted on a wheeled trailer, or on a movable pallet or other movable mounting means. The battery exchange vehicle is operable to be raised onto the mounting means by a lifting means on the front or rear of a tractor or fork-lift truck. This embodiment provides an example of an electric farming system which would have a lower capital cost than the alternative embodiments described herein. The electric tractor or other vehicle is operable to move the trailer or pallet, carrying the spare batteries and battery exchange vehicle, to the land area, or field, to be worked. The battery exchange vehicle is connected to, or plugged in to, the most convenient power connection once the tractor has reached its intended working location. When the tractor battery reaches the optimum level of discharge, the tractor travels the short distance to the battery exchange vehicle to exchange the discharged battery for a charged battery. The battery exchange sequence in this embodiment may be automatic or may be controlled by the tractor driver.

The exchange mechanism in the present embodiment may be located on the tractor rather than on the battery exchange vehicle. In this case, the tractor is provided with a small permanent battery to power the exchange mechanism and to power the tractor when moving the short distance out of alignment with the discharged battery and into alignment with the charged battery. In the foregoing examples, the farm vehicle has been exemplified as a tractor. However, the skilled person will appreciate that the tractor could equally be an alternative self-propelled electric vehicle, for example a combine harvester, crop sprayer or the like. The path of the electricity supply line in the present invention acts as an umbilical cord for the farming system of the present invention. Autonomous or human-controlled transport vehicles powered from the electricity supply line, via trolley poles or connective posts, may be utilised to bring inputs such as seed, fertiliser, pesticides and water from the farmstead to the part of the farm where operations are taking place. Furthermore, the said autonomous or human-controlled vehicles may be utilised during the harvest to transport grain and other crop outputs to the farmstead from the field.

Passing places could be incorporated along the supply line every few hundred metres, with provision for continued electric connection, to allow battery exchange vehicles and/or other autonomous or human-controlled vehicles to pass each other along the tracks between the farm base and the field. Alternatively, or additionally, power could be supplied to the battery exchange vehicles and/or other autonomous or human- controlled vehicles by a battery when the said vehicle becomes temporarily disconnected from the power supply line. The battery in this case may be a separate battery carried by the vehicle for the purpose of being a "back-up" battery, or may be the or one of the batteries being stored in the vehicle for exchange with a battery being used by the tractor or other farm machine.

The present invention provides a system which is able to carry out precision field work using electricity as the power source. The electricity may be farm produced or derived from nuclear, coal, gas and/or renewable energy sources.

Since tractor steering by GPS makes driverless, or autonomous, tractors now possible, electric tractors have the advantage of being more reliable and controllable and, therefore, more suitable for this purpose. The relative constant torque of electric motors even at low speeds would improve the performance of an electric tractor compared with a diesel tractor of the same rated power.

The system would also be effective at saving costs to farmers, especially as all batteries in the system would start the day fully charged, having been charged using off-peak electricity.

The device of the present invention provides a green alternative to conventional farming systems. The device of the present invention also provides a neat solution to be able to keep track of current operations on a farm, for example by monitoring power usage in the supply line, and/or by intercepting signals being transmitted between tractors (or other agricultural vehicles) and the battery exchange vehicles.

Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.