Wow... that is some neat stuff. I can see agri-tractors as definitely being operated viably on electric power. Highway semi-truck tractors on the other hand, not so much, but that is a different story all together.
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"Although the world is full of suffering, it is full also of the overcoming of it." - Helen Keller -- Jeremiah Bailey Central Indiana
My connection speed is way too slow to watch videos.
If you do a Youtube search for John Howe Solar Golf Cart there are a couple of excellent clips.
John Howe is a professor somewhere in Maine. Took an electric golf cart, put PV panels on the roof, added a charge controller and an inverter, probably some other modifications. A video shows him driving the golf cart into the woods, plugging in an extension cord, cutting a tree down with an electric chainsaw powered from the golf cart.
Pretty nifty rig.
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It was under "John Howe's electric chainsaw" There is a part of the clip where he says he put about $7k into it. Not too bad a price for mechanized fuel-less transport. I suppose one could attach things to the golf cart for added versatility.
Its essentially a solar PV generator on wheels. Electricity where you need it. Did you catch the part about plugging it into his house if the power goes down?
If it can be plugged in, it can be powered by this rig. Chainsaws, lawn mowers, brush trimmers, power tools, post hole diggers, pumps, all sorts of uses.
There are communities where golf carts are allowed on local traffic roadways. I've used these things in some of the plants I work at to get around. 25 MPH is easy to do. We have to put limit switches on them to stay under the sped limit of some of these places or the guys will tear up the road! I've loaded them up with a couple of hundred pounds of tools and materials, electric and gas models.
What if you added a trailer hitch? Hauling cargo to a farmers market would be a fine use.
Theres another video somewhere with an electric tractor, same idea as the golf cart. Probably not too many horses, so you wont be baling hay, but smaller implements would work for sure. brush hogs, finish mowers, tillers, a boom. Lots of versatility.
I'm all for simplicity and sustainable methods, but there is nothing wrong with some darn handy machines.
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The big thing with electric tractors is that they have a lot of weight - so they improve traction. Standard tractors usually fill the big tires with a liquid that gives the tractor more weight.
Also, with electric, you don't ever get too far from your charger.
I was concerned about the use of tracks - but the idea is that you get more traction and your weight is spread out - so less compaction.
A guy at work just picked up 11 acres, wants me to go look at it. He wants to get some cows on 4 acres, raise tomatoes on 7. We got to talking about tractors and fuel prices. There are numerous projections that fuel prices will rise again. The trend in food production is moving towards relocalization and at least all natural if not organic methods. A solar powered electric tractor would be well positioned to take advantage of this developing trend. Such a device need not be enormous. Something able to plow and till a backyard garden would be in great demand. The size would also be able to service a field of several acres.
I'll be keeping this one in the back of my mind.
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my grandparents bought a used Club Car golf cart years ago to drive around their small farm. at some point, the roof broke and a tire went flat and batteries wore out. it sat in the barn for at least five years, maybe closer to ten, just taking up space. the keys were lost at some point.
well, I've been very slowly cleaning out the barn and that thing was taking up way to much space for something that didn't work. so I took it to the dump. psych your mind! a few bucks for new keys and switch, $240 for six deep cycle six-volt batteries, a sore back from moving the batteries around, and it's right as rain again. the roof is still busted up, but that should be easy to replace.
there's also a little trailer here that somebody bought to pull behind a riding lawnmower. jury-rigged a hitch using a galvanized eye bolt and I've been hauling firewood around today. I wasn't sure how the cart was going to handle towing, but it did fine. I probably loaded up 300 pounds and I didn't notice any difference from when it was empty. I suppose there are some fat golfers out there, so this shouldn't surprise me, but I was very pleased. certainly not things I would have bought, but since they were already here I'm happy to use them.
I'm no electrical engineer, so forgive me if this is a dumb question, but could the charger (plugs into 120-volt AC) be modified to flow the other direction as an inverter? using an electric chainsaw today would have saved me a pair of pants (don't ask).
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Standard tractors usually fill the big tires with a liquid that gives the tractor more weight.
water and calcium chloride in my experience. makes blowouts more interesting...
the one problem that's bothering me about these battery powered contraptions is the lead involved. maybe it's negligible, but I can't help but think there's going to be some lead sulfate falling onto the ground at some point. I guess proper maintenance and good design could prevent this altogether.
We use an electric tractor made by G.E. back in the early '70s. We bought it for $100 but it had been abused with overfilled batteries, corrosion from that, and miswired relays. It's a 36-volt model running on GC-2 golf cart batteries and it charges from our home's PV panels. We added a bit more weight (70 lbs.) by bolting on a 36-volt inverter to run an electric chain saw. Mostly we use it for cutting the 1 cord of boxelder firewood that we use in a year and to mow some trails and orchard. It has a 42-inch mower, a grading blade, a 1-bottom plow, tire chains, and a 30-inch rotary tiller. The tiller is nice for cutting up a green manure crop after mowing it, but I'd never think about tilling on bare ground since a shovel or fork works so much better without over-fluffing the soil. You can see the tractor by clicking on our web page at http://www.geopathfinder.com/9659 , or there are more details found on links at that page.
I'm no electrical engineer, so forgive me if this is a dumb question, but could the charger (plugs into 120-volt AC) be modified to flow the other direction as an inverter? using an electric chainsaw today would have saved me a pair of pants (don't ask).
Sorry, but the answer is no. The charger takes the AC and converts it to DC, a fairly simple task. Converting DC to AC, not so simple. Think of it this way: it's a simple matter to take your log and split it into pieces; it's quite a different matter to take those pieces and put them together into a solid log.
Inverters, though, are often built with on-board chargers. The Tripp-Lite APS 3636VR on our Elec-Trak E-15 tractor can charge the tractor's batteries at 20 amps OR it can run two AC circuits at 15 amps each. That translates to two electric chainsaws running at the same time, full power. Not that I'd need it but it's nice to have some reserve capacity to ensure durability. The biggest downside is modified sine-wave output instead of true sine-wave. The cheaper option was over $700. As bad as that was, the sine wave option is REALLY pricey!
Nice analogy! Thanks! Inverters, though, are often built with on-board chargers. The Tripp-Lite APS 3636VR on our Elec-Trak E-15 tractor can charge the tractor's batteries at 20 amps OR it can run two AC circuits at 15 amps each. That translates to two electric chainsaws running at the same time, full power. Not that I'd need it but it's nice to have some reserve capacity to ensure durability. The biggest downside is modified sine-wave output instead of true sine-wave. The cheaper option was over $700. As bad as that was, the sine wave option is REALLY pricey!
Bob.
One thing to point out: The cheapest and simplest DC-to-AC inverters used mechanical devices to "chop up" the DC to make AC. The result is what's called a square-wave. These kinds of inverters need to have a LOT of electrical shielding, otherwise the interference it produces will wipe out all radio communications in the area. The resulting square-wave AC, for all intents and purposes, can only be used in tube-based electronics or incandescent bulbs. Unless the motor is specifically designed to work with square-wave AC, square-wave AC will "seriously reduce the life" (i.e., burn out) your standard AC motor. Modified (aka, "stepped") sine-wave AC can generally be used by both AC motors and most electronics. Generating pure sine-wave AC from DC with any kind of efficiency is a non-trivial task, and is only a concern if you're using very expensive electronic equipment.
One type of inverter that used to be available for the Elec-Trak was simply two motors joined at the output shaft. One was 36-volt DC and the other was 120-volt AC. While it was heavy (for an equivalent output), and only peaked at about 80% efficiency, it was fairly inexpensive and not much less efficient than a modern, $2000- $3000, sine-wave, electronic inverter (which runs about 85%). Efficiencies on the cheaper modified-sine-wave inverters is usually listed as 95+%, but this figure includes all of the high-frequency transistor switching noise that motors and transformers simply convert into heat and vibration ("hum").
I looked in vain for the 36-volt chainsaw that used to be available for the Elec-Trak but didn't find one. Besides the high cost of what's now a hard-to-find antique, I would have had to lug around a heavy cable to handle the low-voltage current. 120-volt is easier to use but inverters are their own trade-off, cost-wise and in efficiency loss.
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