EVs Can Bring RE to the Field
by Jim Coate
September 14, 2005
|Note: This article was originally written for and pulished in The Natural Farmer, |
the newspaper of the Northeast Organic Farming Association (NOFA).
Copyright 2005, The Natural Farmer. Reprinted by permission.
|I have long been a proponent of electric vehicles, tools, and machinery. Using electricity as a power source means that can you refuel with a variety of energy sources, such as solar, wind, or hydro, something you just can't do with internal combustion engines. In some vehicles, electric motors can even "recycle" the power by storing power from braking on down hills and saving it for use the next time you accelerate. Electric motors produce no pollution (at least at the point of use) and so are great for those with chemical sensitivities (MCS), are quiet, give off little waste heat, and are low maintenance.|
Ron Khosla uses his electric G to weed the beans
I'm also interested in bio-diesel as an alternative fuel source. Although it still requires an internal combustion engine with the resulting noise and (limited) pollution, the ability to use a locally produced fuel makes it attractive . A few farms such as Hawthorne Valley in Columbia County of New York, are now using a still to refine used vegetable oil from local restaurants into diesel fuel to power their tractors and delivery trucks. On a small scale, this can work well, but on a large scale I remain skeptical as The Big Guys would like to market bio-diesel produced directly from crops such as soy beans. Land for growing these crops would compete with land needed for food. The growing would likely be done using genetically modified seed, using major pesticide applications, and using synthetic fertilizers likely derived from natural gas, all of which makes it a very inefficient way to extract the energy that is otherwise directly available from the natural gas.
|The new bio-diesel still at Hawthorne Valley Farm processes used vegetable oil into fuel to power tractors, a pick-up and a delivery truck. The process begins with waste vegetable oil collected from restaurants which is heated and filtered. It is then combined with methanol and lye. These extra ingredients react to produce the catalyst needed to separate the esters from the glycerin to refine the oil into usable fuel. The resulting bio-diesel is then used in an unmodified diesel vehicle, although some regular (petroleum based) diesel may need to be mixed in to keep it from getting too thick, particularly in cold weather. The farm is presently using a small still as an educational tool. Once issues of waste by-product disposal have been resolved and the process is streamlined, the long term goal is to develop a concrete business plan for implementing a larger still and ramp up production.|
Over the past decade or so I have tinkered first with making an electric bicycle (much better versions of which can now be bought commercially from many retailers), and have owned and driven on a daily basis an S-10 pickup truck converted to run as battery electric. I am now trying out one of the few factory made all-electric S-10's, which offers more creature comforts and better performance but is harder to work on as it is a large "black box". I have also amassed a small collection of Elec-Trak battery-electric garden tractors. These were made by GE about 30 years ago and can still be found around the country, especially in the Northeast. My hope is to find the time to produce some of the parts needed for upkeep and restore some for those looking for ready-to-use tractors.
The GE Elec-Trak had numerous accessories, including a powered roto-tiller, as seen in this vintage advertising picture.
|I have been living near Boston, and as such my outdoor experience has been limited to upkeep on an urban yard. I have used an Elec-Trak with a roto-tiller on back to break up old sod and then a plow blade on front to grade the back yard. I have also used the Elec-Trak to mow, but the space is too small for it to be a practical method. Instead I have been using a Husqvarna cordless battery electric push mower which, although no longer made, works nicely for a smaller yard. Ryobi made a slightly larger cordless push mower which I've been told is also good for yard mowing. Both models can be found used, often "broken" but really just in need of new batteries. As my entire yard is within 150' of an outlet, I found a 16" corded electric chain saw to be great for removing a couple of medium sized trees. It is also handy for upkeep as it can sit for a year and still be ready to go immediately when I turn it on.|
I'm now in the process of moving to upstate New York where I will have several acres to keep mowed and will be putting the Elec-Traks to the real test, and may eventually have the opportunity to try some more of the agriculture related tools. I have talked with a variety of other people who having glowing things to say about their Elec-Traks, and one person who has converted a larger "G" tractor to battery electric for use with his CSA based farm.
I spoke to Bella Kaldera at Cauldron Farm in central Massachusetts, who has an Elec-Trak and a smaller electric golf cart. She was fortunate to come into these for the cost of repairs to get them running and now simply "loves the electric vehicles". Her biggest use at the moment is for cargo carrying and towing. In the winter she mounts a blade on front for plowing the driveways. GE sold the Elec-Traks with typical mowing decks, but Bella has plans to convert a used sickle-bar mower to fit, so as to be able to save the cut grass as hay. Ideally Bella would like to have a front end loader for the Elec-Trak, but factory original versions are extremely rare so this may be a home built project some day. Her main goal is to build up a collection of photo voltaic (PV) solar panels and be able to charge both vehicles from the sun. This fits in with the goal of the farm to provide a model of sustainable living for those living there, as they raise their own animals and vegetables and take advantage of everything the land has to offer.
Another Elec-Trak user regularly uses his tractor pulling a roto-tiller (powered by a separate motor) to weed between the rows of his strawberries. A used Elec-Trak can run anywhere from $50, needing a lot of work, up to $800 or so in decent condition. The electric roto-tiller attachment was made by Brinly Hardy for GE, but can be a bit hard to find one now. An alternative is to add a sleeve-hitch receiver to the Elec-Trak and then pull a variety of attachments behind the tractor. Brinly Hardy, Craftsmen, and various other makes of sleeve hitch plows can be found used for $50-$100. Such a set up could be great for a market gardener wanting to use it for primary cultivation.
The low end torque of electric motors makes them a great power source for pulling and towing. In larger sizes, an avid electric vehicle builder and racer in Oregon tells tales of using his electric pickup truck to tow his race car, another large truck in need of repair, and another trailer all at once as a small "train". Elec-Trak users also like to brag about the thousands of pounds towed, moving various wagons and machinery. One person in North Carolina had his 1956 Allis Chalmers WD-45 with bush hog break down in the field and used his Elec-Trak to tow the 5000 pound rig back to the barn for repair. I too have seen this power using my Elec-Trak to push mounds of dirt around. The tires are the limit as they always slip long before the motor runs out of power.
The Elec-Traks are a great match to any farm for moving people and materials (as could a golf cart) and it works well for mowing and snow plowing, and doing field work on smaller operations. For a somewhat larger grower, a bigger tractor with more ground clearance and bigger tools is needed. It turns out that the classic Allis Chalmers "G" cultivating tractor is a great match to this task. It has the advantage of having the tools mount under the belly, where the driver can easily see what is happening, and the mechanical layout of the tractor with the engine hanging off the back makes it a great candidate to convert to battery electric power. Ron Khosla of the Huguenot Street Farm in upstate New York has done just this, and I recently had the pleasure of visiting him to see the results first hand.
|As I toured the farm, it was obvious that Ron is a bit of an inventor. He has rigged a standard window air conditioner to regulate to refrigerator temperatures for storing produce on CSA pick-up days. And using simple plastic tubing from solar collectors, he has made an ingenious radiant heating system for the greenhouse. Water heated by a small gas-fired flows though the tubing which is under the flats of seedlings, with a layer of reclaimed foam insulation board under the tubing, and ends up costing 1/10 of what it would cost to heat the entire space. His house is also an ongoing experiment, using SIPS (Structural Insulated Panels) that provide high R-value for the exterior walls and roof, with radiant tubing installed in the concrete slab floor. Ron has found that the insulation is so good that just a small space heater keeps the house warm most days without even using the radiant system.|
Ron has heard about bio-diesel conversions for G's as being the latest rage but feels that it not worth the effort as a fair bit of skill with internal combustion engines is required and the converted engine will still suffer from long term costs and ongoing maintenance issues. For comparison, he emphasizes that the electric conversion can be done by anyone without specialized skills in a weekend or so of work, and requires little upkeep.
The motor is mounted to an adapter plate which then fits on the rear of the tractor.
Huguenot Street Farm provides CSA shares to 230 families and supplies three restaurant accounts, using about 8 acres for growing (out of 24 acres in rotation). With the equivalent of only about two and a half full time people working the farm, Ron feels that their success is due in large part to the efficiency that comes from using the electric "G". He says the local folks around town, the local papers, and the resturaaunts he supplies all love the "crazy hippies with the electric tractor".
Ron initially converted one G to electric on a true shoe string budget, making things up as he went. He learned a few hard lessons about battery care and the importance of a good charger, but absolutely loved the tractor. Since then he has converted a second tractor as part of a SARE grant to help show others how it is done, and documented the project at http://www.flyingbeet.com/electricg. In addition to the two electric's, he maintains one larger diesel tractor for opening up new fields and other heavy work. Ron estimates that 65% of the tractor work is done with the electric G's.
A hydraulic pump mounted under the seat provides power to lift the tool bar.
|When using the tractor in the fields, Ron finds that it is good all day on one battery charge, as he has a diversified operation so the tractor is not in continuos use. When the tractor is in a remote field, it is often connected to a solar panel to recharge and be ready the next time they need to use it, or if working near the house it is simply plugged in to a regular outlet during lunch or overnight. The G I got to see in action is set up with Cub tires which are wider and provide more traction than original G tires. It has also been equipped with a home made tool bar that allows him to use commonly available (so inexpensive) tools. After a few moments to set the spacing on the shoes, Ron was off cleaning out the weeds amongst his beans. As promised, the tractor was very quiet in operation; I was able to walk along a row or two away and easily talk with Ron as he drove along.|
When converting the G, Ron selected a gear ratio for the new motor such that it easily runs at very low speeds. Combined with the massive low end torque of electric motors, this makes it a very powerful tractor. As Ron says, "I have way more power now, and perhaps most importantly for organic farmers., they go much much slower. I can creep along at a 100 feet an hour... and that's awesome! If we had a transplanter, it would be essential." How also finds that he is much more likely to take a moment to stop the tractor and re-adjust the tools for better results as the electric motor is fully off when stopped.
The conversion parts are very similar to the system used in an electric golf cart. A 48-volt battery back powers a series-wound DC motor, with an electronic controller connected in between to set the speed. Other components such as a contactor provide a safe way to turn the system on and off, and a "pot box" sends a signal from the throttle lever to the controller to tell it how fast to go. The 48-volt battery pack is made up of four 12-volt batteries connected in series. These are deep cycle batteries that, unlike regular car starter batteries, are designed to be repeatedly discharged and recharged. Alternatively, a set of eight 6-volt deep cycle batteries (golf cart batteries) could be used for longer running times. Ron replaced the original hydraulic pump with an electric unit, such as used to operate snow plow blades. It is connected to a 12 volts rather than the full 48 volts that the drive motor uses. As I got to see, the electric pump version works quite well, and lifts the tool bar faster than the original. The conversion parts, including drive motor, adapter plates, batteries, controller, and miscellaneous widgets will total about $3,000.
|Finding a used tractor to convert can require a bit of searching. Used G's with working engines often go for over $3,000 while one with a bad or missing engine can be had for $1,000 - $1,200. Orange County in New York historically had a large number of the G's and may be a good place to look. Ron has found that word of mouth is the best way to find a good frame left in someone's field, and suggests asking old-time farmers and placing want ads. In total, the tractor plus conversion parts costs $4,000 - $5,000 for the complete, ready to use electric G.|| |
The batteries, motor, and controller all mount on the rear of the tractor, along with an extension rack to carry tools and cargo.
Ron is quite clear that "we absolutely couldn't farm without the two G's, and as electric vehicles they are cheaper to run, quieter and more powerful". This echoes the experience of Bella and others with the smaller Elec-Traks. Electric tractors are not just another tool, but something their users truly believe in. I remain happily biased that electric vehicles of all sorts, with a variety of alternative power sources used for recharging, will play an important role in the years to come. More information on my developing electric vehicle projects can be found at www.eeevee.com or I can be contacted by e-mail at firstname.lastname@example.org.
|See additional pictures in my2005 TNF photo album.|
|Jim's E-Home||January 26, 2006|