In 2007, John Deere introduced two special 7030E Premium Series tractors at the Agritechnica machinery show in Hanover Germany. These tractors could produce high-voltage electricity to drive implement systems instead of relying on PTO or hydraulics. They were the first commercially available farm tractors from a major manufacturer to offer that feature. Their onboard generators also fed plug outlets capable of running power tools and other devices.
But they didn’t seem to woo many buyers. I asked Rory Day, editor of Classic Tractor magazine in England, about the popularity of the 7030E Premiums. His response was he hadn’t seen one or heard a thing about them after their official launch, and he doesn’t know of any owned by U.K. farmers. He keeps a pretty close eye on the tractor market there, so if hasn’t seen one, they must be ultra rare.
That’s no surprise, though. Electric-drive technology is still cutting edge and it takes a while for companies to introduce implements capable of making use of it. Up until now there has been one major impediment to its wider introduction: there was no standardization around the technology. The work to create those standards, however, is currently underway.
“The first objective is to create a common adapter right now between the tractor and implement,” says Ken Edwards, spokesperson for AEF, the Agricultural Industry Electronics Foundation. That group is responsible for evaluating and establishing the engineering standards for electrical components used on farm equipment. “At AEF, we’re trying to standardize plug-and-play connections.”
The universal tractor-to-implement connection and overall system specifications will be available soon. “It’s not inconceivable that it (standardized electric drive) could be marketable within 12 months,” he adds.
Once standards are in place, manufacturers can begin introducing new products and be confident their design won’t suddenly be incompatible with what the marketplace demands. “I think at Agritechnica 2013 all the big manufacturers will have at least one machine to show with electric drive,” says Michael Feider of Jetter Mobile Applications.
His electronics company showed an example of what the standard high-voltage, tractor-to-implement connection will probably look like during the last Agritechnica in November. “AGCO and Deere have already agreed on a standard plug,” he adds. That was the design on display at his company’s exhibit. Acceptance by the major manufacturers will have a lot of influence on the final design selected by AEF’s working group, which is made up of engineers from those and other companies.
John Deere 6210RE
John Deere appears confident it knows how the electric-drive standardization efforts will come out, and it’s getting a jump on the market. At the 2011 Agritechnica, it introduced a next-generation, market-ready tractor with high-voltage drive. The new 6210RE was displayed at the show with an electrically-powered, mounted fertilizer spreader. The tractor will be available to European customers in May 2012.
“John Deere has built on the success of the ‘E-Premium’ (tractors)”, reads the company’s European brochure. “This revolutionary technology allows electrically-driven attachments to be operated in a way that combines the benefits and high efficiency of a PTO with the infinitely variable, direct controllability of hydraulic drive.”
The 6210RE is capable of providing 20 kW of power to implements. And like the earlier 7030E Premium models, it has 230- and 400-volt AC outlets. European countries use those voltage ratings rather than our 110 and 220 AC standard.
Efficiency and environment
Edwards says he expects the exact industry specifications for high-voltage drive will be at or below 750 volts and 200 amps.
But why go to all this trouble? We already have common hydraulic systems that can provide flexible remote power. In a nutshell, the answer is efficiency. Hydraulic systems are power hogs; they suck up a lot of an engine’s usable horsepower, which reduces the amount it can supply to the tractor’s drawbar.
“You might have 98 per cent efficiency on an electric motor,” explains Edwards. “You’d have much lower efficiency on a hydraulic motor.” Deere’s press release introducing the 6210RE claims using the tractor’s energy-efficient, high-voltage power rather than hydraulic drive can reduce fuel consumption.
Using electricity allows manufacturers to get a little greener, environmentally speaking. By relying less on hydraulic systems, there is a reduced need for hydraulic fluid, which requires petroleum resources to create. And much of it eventually gets spilled into the environment through day-to-day farming operations. Electricity, of course, is much different.
“Everyone wants clean power, and electricity is clean,” says Edwards.
But electricity isn’t without its drawbacks, either. The use of such high voltage systems requires that engineers take a cautious approach to design in order to ensure operator and service technician safety. “Whenever you have a lot of electrical components, one of the first things you look at is the risk to the end user,” Edwards adds. “Safety is a big issue for us.”
Aside from the need for added safety measures, there are engineering constraints. An electric motor must be much bigger to do the work of a comparable hydraulic drive. “For what you can get out of a small hydraulic pack, you need a much larger electric motor,” says Edwards. Eventually, though, research efforts are bound to change that. “There are a number of universities working at the front edge of high voltage,” he adds.
There seems to be no doubt electric drive is set to emerge as an important new component on tractors and implements. In the closing press release from AEF’s July 2011 meeting where engineers discussed the future of the technology, the group summed things up this way: “Overall, the agricultural machinery industry expressed their willingness to adopt electrical power drives in order to improve their existing systems. While there is still a great number of questions that need answers with regard to technical implementation and standardization, the event gave the sense that there is a clear trend towards future applications of electrical power drives.”
All of this means equipment design in the very near future is bound to be a little different than it is now. “I think the look and feel of machinery will change.” says Feider. †