John Deere presented the first fully electric tractor, the SESAM (Sustainable Energy Supply for Agricultural Machinery), in 2016. The GridCON tractor looks very different, as it lacks a cab and rows of batteries underneath the bonnet.
Based on a John Deere 6210R tractor, GridCON utilises a cable connection from the land border to the machine, which transfers power continuously at more than 300kW. A 100kW electric motor powers the IVT transmission, and an additional outlet supplies implements powered by a 200kW electric motor.
A drum attached to the tractor carries up to 1 000m of cable. The length can be extended as required; on the land, the cable is fed out and reeled in, guided by a robot arm to keep the operation friction-free and at low load.
A guidance system prevents the tractor from running into or over the cable.
At work, the tractor autonomously follows pre-set rows at an operating speed of up to 20km/h.
The vehicle can also be guided manually by a remote control. This is particularly useful when manoeuvring the tractor to start work on land borders.
A power supply of 2,5kV AC is required, and the GridCON tractor uses a 700V DC bus for electric power distribution both onboard and for implements.
The machine employs a cooling infrastructure for off-board electrical use. The total efficiency of the drivetrain is approximately 85%.
The empty working prototype GridCON tractor, including cable drum and robot arm, weighs 8,5t. This is about the same as that of the conventional John Deere 6195R, but the GridCON has twice the power. Research engineers aim to reduce the weight by at least 1t.
In addition to this favourable power-to-weight ratio, the concept offers the benefits of silent, emission-free operation.
Moreover, the machine and operating costs of the GridCON tractor are half those of a conventional battery-powered tractor.