In 2022 John Deere launched its Electric Variable Transmission (EVT) on its larger 8 and 9 series models. This option replaces a standard mechanical variable transmission with an engine-mounted generator and two electric motors.
The company will naturally extol the virtues of this approach to getting power to the wheels, and they are many, but another notable benefit of this arrangement is that an electrical power source is readily available to drive implements, which is now generally referred to as off-boarding.
As noted on Agriland in the past, this too has many benefits.
The various driveshafts and belts on a trailed machine, such as a baler, can be replaced with wires and motors which are lighter and do not require the heavy engineering necessitated by tensioned pullies and the torque reaction of shafts.
Maintenance is also reduced and designers have the freedom to organise a machine’s moving parts in ways which are not dictated by the need to get power to them by mechanical drive.
Despite all these boxes being ticked, there has been little take-up from the machinery trade so far.
For many, the concept will be rather radical and and there is the understandable concern that farmers will be unwilling to have live high voltage wires running around the steel frames of attached implements.
Safety concerns
If a mechanical item is damaged, it is usually both audible and visible, but if a high tension wire is abraded or exposed then the damage may not become apparent before it is too late.
No doubt John Deere has thought of this and included in its design trip switches, fault alarms and so on.
Yet there still remains the distinct possibility that, in future, service technicians will need to become qualified electricians to meet health and safety regulations.
Thus we have a beneficial concept hampered by practical concerns, not an entirely original situation and it is one which will require pioneering innovation to explore ways in which the objections might be overcome.
Spudnik test the water
Over in the United States, John Deere has set the ball rolling by partnering with Spudnik, a subsidiary of Grimme, that, just like its parent company, specialises in potato and root crop machinery.
Air separation of the tubers from heavier trash such as clods and stones is a common practice on harvesters, but one of the major problems is that maintaining a constant airflow is hampered by differing loads on the tractor altering the engine speed and hence, fan revolutions.
Spudnik has solved this problem by driving the fan by an electric motor plugged into the rear of the tractor rather than from the PTO.
By doing so, the fan speed can be kept constant independently of the engine speed, which can drop on adverse gradients, either causing poor separation or a reduction in harvest rate.
A further advantage is that air volume can be easily controlled from the cab and set at 10rpm increments via the touchscreen. Although it is not stated by either company, this offers the possibility of further automation as Grimme has been working on camera-assisted separation since at least 2019.
The machine has been trialled with a large potato grower in Washborn, Maine, with great success according to Spudnik.
Yet the application of electric drive to everyday farming has a long way to go yet.
