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Electronics Forum / Basics / August 2008Grid-Battery "Hybrid" Tractors
Supposedly if the tank is connected to the vehicle's engine, it's technically legal to bring 8 pesos/litre [$3/gallon] fuel across the border from Mexico. If the tank isn't connected, customs wil seize the diesel and maybe even the vehicle. Even if it is connected, customs may give you a hard time. Supposedly a driver can earn $100 a trip running diesel in border areas but each border crossing takes an hour or so . . . It's a whole lot more cost effective to just electrify the #@!%&*! tractors and fields. A 1/2 mile long wire 10 - 20 feet above the ground only needs to be on one end of a quarter square. A fast discharge battery can be relatively small as the tractor only needs to go one mile for the round trip back to the wire. An on board ICE or battery trailer could be used to relocate the tractor any distance. As agriculture become more automated there won't be any reason for anyone to be in the tractor so no one will get bored as the tractor lingers for a minute or so charging up at the wire. If someone wants to ride in the tractor he can bring other work to do during recharge. Bret Cahill >Supposedly if the tank is connected to the vehicle's engine, it's >technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 16 lines] >anyone to be in the tractor so no one will get bored as the tractor >lingers for a minute or so charging up at the wire. What sort of battery charges in a minute or two? And where would all that power come from, in the middle of a corn field? Do the math: say, 50 horsepower-hours: How much power to recharge in two minutes? What would the voltage have to be to keep the wire losses reasonable? How much do the batteries weigh? How much do the batteries cost? Ideas are cheap, as long as you ignore reality. John >>Supposedly if the tank is connected to the vehicle's engine, it's >>technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 32 lines] > > Ideas are cheap, as long as you ignore reality. I think this could also be accomplished by stringing a grid of wires over the field, and using a trolley that rides on the wires. It's not as simple as a locomotive or streetcar, where a single hot wire can bu used, and the return current through the tracks. But I think a system could be devised to provide electricity to a tractor by means of a controlled tether. It could definitely be done with a set of tracks that would move the supply line to be in-line with the movement of the tractor, and then have a trolley with a power cord that supplies the tractor. It would involve some engineering, initial investment, and maintenance, but should be about 95% efficient for energy conversion. Paul >>>Supposedly if the tank is connected to the vehicle's engine, it's >>>technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 45 lines] > >Paul Even better, build a solid roof over the entire field, and sheath the underside with conductive metal, like the bumper cars at the beach. Or how about a tower, with a laser or microwave beam aiming power at a collector array on the tractor? Or hang a cable to the tractor from a tethered satellite with solar cells. Or go back to using oxen. That will revive the whip business, creating many jobs. Life is so much more exciting without math. John >>>>Supposedly if the tank is connected to the vehicle's engine, it's >>>>technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 55 lines] > Even better, build a solid roof over the entire field, and sheath the > underside with conductive metal, like the bumper cars at the beach. Well, the solid roof would block rain and sun, but a metal grid would work. However, the bottom conductive plate would not grow much corn. > Or how about a tower, with a laser or microwave beam aiming power at a > collector array on the tractor? That is a horror movie waiting to be put on You-Tube > Or hang a cable to the tractor from a tethered satellite with solar > cells. They are working on geosynchronous satellites on tethers that might make that a reality someday. > Or go back to using oxen. That will revive the whip business, creating > many jobs. If the economy deteriorates enough, people may need to go back to a simpler way of life. We may need to take lessons form the Amish. Putting more people to work doing hard physical labor would be a good thing. Not so many bored, unhealthy kids (and adults) blowing off their excess energy and frustrations by driving aggressively and playing violent computer games. > Life is so much more exciting without math. I think my idea has a chance to work. Probably more practical than batteries. Paul > Life is so much more exciting without math. And engineering. The possibilities are endless. Graham > I think this could also be accomplished by stringing a grid of wires over > the field, and using a trolley that rides on the wires. That's certainly possible -- the "trolly tractor" was last summer's idea -- but requires a lot of wire. It's actually cheaper to use a battery. > It's not as simple > as a locomotive or streetcar, where a single hot wire can bu used, and the [quoted text clipped - 5 lines] > initial investment, and maintenance, but should be about 95% efficient for > energy conversion. Another option is to eliminate the tractor altogether and drag the plow and other impliments off of a "super pivot," the common "crop circle" irrigation structure beefed up for the heavier load. The impliments would move inward for a spiral furrow. Bret Cahill >> I think this could also be accomplished by stringing a grid of wires over >> the field, and using a trolley that rides on the wires. [quoted text clipped - 18 lines] > >The impliments would move inward for a spiral furrow. Um, you might reconsider any plans you have to be a farmer. John > >Supposedly if the tank is connected to the vehicle's engine, it's > >technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 3 lines] > >trip running diesel in border areas but each border crossing takes an > >hour or so . . . > >It's a whole lot more cost effective to just electrify the #@!%&*! > >tractors and fields. > >A 1/2 mile long wire 10 �- 20 feet above the ground only needs to be > >on one end of a quarter square. �A fast discharge battery can be > >relatively small as the tractor only needs to go one mile for the > >round trip back to the wire. �An on board ICE or battery trailer could > >be used to relocate the tractor any distance. > >As agriculture become more automated there won't be any reason for > >anyone to be in the tractor so no one will get bored as the tractor > >lingers for a minute or so charging up at the wire. > What sort of battery charges in a minute or two? One with lots of small cells. The smaller the cells, the faster the charging time. > And where would all > that power come from, in the middle of a corn field? The grid: Coal fired plants, nukes, PV, dish Stirling, geo thermal, wind . . . whatever they got that will put out some juice. Polar bears, tropical frogs and hurricanes are not the issue. > Do the math: say, 50 horsepower-hours: Plug in hybrids can go 40 miles between charges. A tractor may require 20X higher hp than a Volt but a tractor only needs to go 1 mile between charges. > �How much power to recharge in two minutes? If a 400 hp articulated tractor moves 10 mph it's only running 6 minutes between charges and will require 3X 400 hp or ~ 1 MW -- 1/6th the juice drawn by an electric locomotive. In 4 years diesel will be $15 / gallon and electrification will amount to hundreds of dollars/hour in savings, much more money than necessary to hire someone willing to sit at the end of the field for a few minutes reading a magazine charging up between furrows. > �What would the voltage have to be to keep the > �wire losses reasonable? It's only a half mile so a fat high current low voltage wire might be desirable for safety reasons. > �How much do the batteries weigh? Regardless of the size, from the articulated tractor sucking down 22 gallons of diesel/hour [$110/hr and spiraling] to a 15 hp garden tractor, the battery + electric motor system will always have a higher specific power than any IC engine + fuel tank system. The reason is a tractor just doesn't need to go very far to work a field. > �How much do the batteries cost? Same as the batteries in plug in hybrids which require an even larger battery / hp. > Ideas are cheap, as long as you ignore reality. In as little as 8 years a lot of the big wells will give out rather quickly leaving the world with 2/3rds of current production according to a recent _London Times_ interview with a former BushCo aid. On top of that China seems to have a permanent double digit growth rate while, according to Soros, the U. S. will be in a decades long recession so the size of China's economy will surpass America's in as little as 6 years. This will leave the great majority of Americans to try to get by on a couple percent of the oil we consume today. So here are 3 plausible scenarios: 1. electrify the fields & tractors, or, 2. return to plowing fields with oxen, or, 3. starve. If you cannot come up with any ideas, cheap or otherwise, for a plausible 4th scenario then I say we electrify the fields. Bret Cahill "Every idea is the product of a single mind." -- Bishop Richard Cumberland > >Supposedly if the tank is connected to the vehicle's engine, it's > >technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 3 lines] > >trip running diesel in border areas but each border crossing takes an > >hour or so . . . > >It's a whole lot more cost effective to just electrify the #@!%&*! > >tractors and fields. [quoted text clipped - 6 lines] > >anyone to be in the tractor so no one will get bored as the tractor > >lingers for a minute or so charging up at the wire. > What sort of battery charges in a minute or two? One with lots of small cells. The smaller the cells, the faster the charging time. This should be common knowledge. > And where would all > that power come from, in the middle of a corn field? The grid: Coal fired plants, nukes, PV, dish Stirling, geo thermal, wind . . . whatever they got that will put out some juice. Polar bears, tropical frogs and hurricanes are not the issue. > Do the math: say, 50 horsepower-hours: How big is this field or tractor gonna be? Plug in hybrids can go 40 miles between charges. A tractor may require 20X higher hp than a Volt but a tractor only needs to go 1 mile between charges. > ?How much power to recharge in two minutes? If a 400 hp articulated tractor moves 10 mph it's only running 6 minutes between charges and will require 3X 400 hp or ~ 1 MW -- 1/6th the juice drawn by an electric locomotive. In 4 years diesel will be $15 / gallon and electrification will amount to hundreds of dollars/hour in savings, much more money than necessary to hire someone willing to sit at the end of the field for a few minutes reading a magazine charging up between furrows. > ?What would the voltage have to be to keep the > ?wire losses reasonable? It's only a half mile so a fat high current low voltage wire might be desirable for safety reasons. > ?How much do the batteries weigh? Regardless of the size, from the articulated tractor sucking down 22 gallons of diesel/hour [$110/hr and spiraling] to a 15 hp garden tractor, the battery + electric motor system will always have a higher specific power than any IC engine + fuel tank system. The reason is a tractor just doesn't need to go very far to work a field. > ?How much do the batteries cost? Same as the batteries in plug in hybrids which require an even larger battery / hp. Are you now claiming plug in hybrids are a scam? > Ideas are cheap, It only seems that way to those who have none. > as long as you ignore reality. The reality is in as little as 8 years a lot of the big wells will give out rather quickly leaving the world with 2/3rds of current production according to a recent _London Times_ interview with a former BushCo aid. On top of that China seems to have a permanent double digit growth rate while, according to Soros, the U. S. will be in a decades long recession so the size of China's economy will surpass America's in as little as 6 years. This will leave the great majority of Americans to try to get by on a couple percent of the oil we consume today. So here are 3 plausible scenarios: 1. electrify the fields & tractors, or, 2. return to plowing fields with oxen, or, 3. starve. If you cannot come up with any ideas, cheap or otherwise, for a plausible 4th scenario then I say we electrify the fields. Bret Cahill "Every idea is the product of a single mind." -- Bishop Richard Cumberland > The reality is in as little as 8 years a lot of the big wells will > give out rather > quickly leaving the world with 2/3rds of current production according > to a recent _London Times_ interview with a former BushCo aid. That's oil. Estimates of worldwide recoverable natural gas reserves continue to grow year after year, despite high and increasing consumption. That's because new reserves are being found all the time. > > The reality is in as little as 8 years a lot of the big wells will > > give out rather > > quickly leaving the world with 2/3rds of current production according > > to a recent _London Times_ interview with a former BushCo aid. > That's oil. �Estimates of worldwide recoverable natural gas > reserves continue to grow year after year, despite high and > increasing consumption. �That's because new reserves are > being found all the time. Not completely carbon free but at least we can convert the tractors to natural gas and avoid plowing fields with oxen. Bret Cahill > > The reality is in as little as 8 years a lot of the big wells will > > give out rather [quoted text clipped - 5 lines] > increasing consumption. �That's because new reserves are > being found all the time. Spiraling oil prices will drag up the cost of every other form of portable energy like a rag doll. Forget carbon. Forget AGW. The _only_ serious permanent solution is to electrify the fields & tractors. Bret Cahill > Forget carbon. Forget AGW. The _only_ serious permanent solution is > to electrify the fields & tractors. You mean like slot cars? Or overhead wires like street cars? > > Forget carbon. �Forget AGW. �The _only_ serious permanent solution is > > to electrify the fields & tractors. > You mean like slot cars? �Or overhead wires > like street cars? Just one 1/2 mile long wire on one end of a quarter square. The tractor only needs a small battery to make each pass, about a mile. With two wires, one at each end, the battery can be even smaller. The GM Volt goes 40 miles between charges. The tractor goes one mile. Or 1/2 mile. Bret Cahill > > > Forget carbon. �Forget AGW. �The _only_ serious permanent solution is > > > to electrify the fields & tractors. [quoted text clipped - 3 lines] > > Just one 1/2 mile long wire on one end of a quarter square. An extension cord! Of course! > > Forget carbon. �Forget AGW. �The _only_ serious permanent solution > > is > > to electrify the fields & tractors. > You mean like slot cars? �Or overhead wires > like street cars? Just one 1/2 mile long wire on one end of a quarter square. The tractor only needs a small battery to make each pass, about a mile. With two wires, one at each end, the battery can be even smaller. The GM Volt goes 40 miles between charges. The tractor goes one mile. Or 1/2 mile. ========================================================================= I think you are fixated on batteries. Why not plant in circles as they do with pivot arm irrigation, and then use a variation of the pivot arm to provide power to the tractor? The tractor could be made to ride along with the pivot arm, and each pivot could be provided with a fairly small distribution transformer and a DC bus supply powered from a grid of underground cables. The tractor could have a standard three phase motor driven by a V/F controller directly from a DC supply cable on a reel. Much of the system could be automated. Circular crop fields (not alien crop circles) are already used in some areas where 100% land use is not needed, and the unused areas could be used for small yield alternate crops tended by hand, or just for wind and erosion buffers. http://ask.metafilter.com/44058/Since-when-did-farmers-grow-circular-crops http://www.fluther.com/disc/1721/why-are-some-agricultural-fields-circular-espec ially-in-the-midwest/ http://www.dvorak.org/blog/?p=2618 http://www.ext.colostate.edu/PUBS/crops/04704.html http://ga.water.usgs.gov/edu/irsprayhigh.html http://www.piercecorporation.com/home.html http://www.pivotirrigation.com.au/ And looky here! It's been discussed ad nauseam elsewhere! http://terraverde.wordpress.com/2008/04/07/exchange-with-phil-timmons-re-the-ele ctric-farm/ I think it's an excellent idea and will be commercially available soon. Paul >> > Forget carbon. ?Forget AGW. ?The _only_ serious permanent solution is >> > to electrify the fields & tractors. [quoted text clipped - 4 lines] >Just one 1/2 mile long wire on one end of a quarter square. The >tractor only needs a small battery to make each pass, about a mile. --- Small battery? Since 1 horsepower is equal to 746 watts, that means that your 400 horsepower tractor needs about a 300 kilowatt-hour battery to work for an hour and, if the motor is rated for, say 300VDC, it'll need to draw 1000 amps from the battery when it's working, and that's not even considering the unavoidable losses. On top of that, if you want to charge the battery up in a couple of minutes that means the charger's going to have to pump more than 120000 amps into it for two minutes and, if your wire is sitting at 1200 volts, it'll have to be able to supply 100 amps to the charger. Again, disregarding losses. Then there's the question of getting power to the wire... The whole thing is a badly conceived, poorly thought out can of worms. --- >With two wires, one at each end, the battery can be even smaller. > >The GM Volt goes 40 miles between charges. The tractor goes one mile. > >Or 1/2 mile. --- And your point is??? JF >> > Forget carbon. ?Forget AGW. ?The _only_ serious permanent solution is >> > to electrify the fields & tractors. [quoted text clipped - 12 lines] > >Bret Cahill In electric-only mode, the Volt will go 40 miles between charges. Recharge time is 6-8 hours. That's no way to run a farm. John > >Just one 1/2 mile long wire on one end of a quarter square. �The > >tractor only needs a small battery to make each pass, about a mile. > >With two wires, one at each end, the battery can be even smaller. > >The GM Volt goes 40 miles between charges. �The tractor goes one mile. > >Or 1/2 mile. > In electric-only mode, the Volt will go 40 miles between charges. And the tractor goes one mile. Or 1/2 mile. Recharge time is two orders of magnitude less than the Volt. Bret Cahill >> >Just one 1/2 mile long wire on one end of a quarter square. ?The >> >tractor only needs a small battery to make each pass, about a mile. [quoted text clipped - 14 lines] > >Bret Cahill Your ideas are excellent. Take them to one of the agriculture-related newsgroups, where people will be grateful for your brilliant suggestions. I'm sure all the farmers in the USA will be cutting spiral rows next season. John >>> >Just one 1/2 mile long wire on one end of a quarter square. ?The >>> >tractor only needs a small battery to make each pass, about a mile. [quoted text clipped - 21 lines] > > John It's more likely that we will move to no-till agriculture. >>>> >Just one 1/2 mile long wire on one end of a quarter square. ?The >>>> >tractor only needs a small battery to make each pass, about a mile. [quoted text clipped - 23 lines] > >It's more likely that we will move to no-till agriculture. Lots of things are practical if yoy kill off about 96% of the population first. John > >>>> >Just one 1/2 mile long wire on one end of a quarter square. ?The > >>>> >tractor only needs a small battery to make each pass, about a mile. [quoted text clipped - 26 lines] > Lots of things are practical if yoy kill off about 96% of the > population first. You dodged the issue: Paying $100 billion a year for diesel for agriculture will _starve_ the population. Bret Cahill >> >>>> >Just one 1/2 mile long wire on one end of a quarter square. ?The >> >>>> >tractor only needs a small battery to make each pass, about a mile. [quoted text clipped - 31 lines] >Paying $100 billion a year for diesel for agriculture will _starve_ >the population. Is that $100b number for the US, or for the whole world? John >Paying $100 billion a year for diesel for agriculture will _starve_ >the population. --- Got some numbers? JF On Tue, 22 Jul 2008 21:29:54 -0700, BretCahill wrote: > Paying $100 billion a year for diesel for agriculture will _starve_ > the population. Just another tool in the fight against obesity. > > Paying $100 billion a year for diesel for agriculture will _starve_ > > the population. > Just another tool in the fight against obesity. What'll happen is they'll get together more often, i. e., public transportation, and eat even more. Bret Cahill .... >>It's more likely that we will move to no-till agriculture. > > Lots of things are practical if yoy kill off about 96% of the > population first. Not sure why you change the topic. My remark was serious : Farmers in the United States already use no-till methods on 37 percent of the nation's cropland. It's likely to increase, since there are many benefits. Only one of these benefits is less fuel needed (since no plowing is done). Rob > It's more likely that we will move to no-till agriculture. Do you actually kno what no till agriculture is? Hint, it involves a sod seeder instead of a combine & ploughing. This discussion has absolutely nothing to do sci.math.num-analysis (or most of the other groups). Kindly take discussion somewhere else.  SignaturePhil Scadden, Senior Scientist GNS Science Ltd 764 Cumberland St, Private Bag 1930, Dunedin, New Zealand Ph +64 3 4799663, fax +64 3 477 5232 >This discussion has absolutely nothing to do sci.math.num-analysis (or >most of the other groups). Kindly take discussion somewhere else. It's an unmoderated group. Just ignore the thread. John > >This discussion has absolutely nothing to do sci.math.num-analysis (or > >most of the other groups). Kindly take discussion somewhere else. > > It's an unmoderated group. Just ignore the thread. We need applied math folk for the final spreadsheet work. No reason to piss 'em off. Bret Cahill This discussion has absolutely nothing to do sci.math.num-analysis (or most of the other groups). Kindly take discussion somewhere else. SignaturePhil Scadden, Senior Scientist GNS Science Ltd 764 Cumberland St, Private Bag 1930, Dunedin, New Zealand Ph +64 3 4799663, fax +64 3 477 5232 >> >Supposedly if the tank is connected to the vehicle's engine, it's >> >technically legal to bring 8 pesos/litre [$3/gallon] fuel across the [quoted text clipped - 21 lines] > >This should be common knowledge. Got a link to the datasheet of a battery that charges in a minute or two? Most common batteries charge at C/10 or thereabouts, which is typically hours. My AA camera batteries take a couple hours to charge. Cell phone ditto. John ..... > Got a link to the datasheet of a battery that charges in a minute or > two? Most common batteries charge at C/10 or thereabouts, which is > typically hours. My AA camera batteries take a couple hours to charge. > Cell phone ditto. Batteries should be specially designed for fast charge/discharge, but it's not at all impossible. You just loose some of the energy density if you increase the power density. Here is one where they did that : http://www.altairinc.com/markets_energy_systems.html Recharges in a few minutes. 35 kWh battery packs are in production. > John >..... >> Got a link to the datasheet of a battery that charges in a minute or [quoted text clipped - 10 lines] >Recharges in a few minutes. >35 kWh battery packs are in production. Give us a break. http://www.altairinc.com/markets_applications.html This is yet another nanotech company that will change the world in a dozen ways, including the mandatory cure of various diseases. They lost $32M last year on $9M in sales. Net shareholder equity is -57 million. Wish'em luck. John Not that pausing a few minutes is a problem either but a fast recharging battery just isn't a serious issue. All that is necessary is make the cells smaller. The smaller the cell, the faster the recharge. This should be common knowledge. Bret Cahill >Not that pausing a few minutes is a problem either but a fast >recharging battery just isn't a serious issue. [quoted text clipped - 6 lines] > >Bret Cahill Show us a link to a datasheet for such a battery. Meanwhile, consider a AA size battery with, say, a 2 AH capacity. Consider charging it in one minute. See the problem? John On Jul 21, 10:45�pm, John Larkin <jjlar...@highNOTlandTHIStechnologyPART.com> wrote: > On Mon, 21 Jul 2008 22:13:12 -0700 (PDT), Bret Cahill > [quoted text clipped - 16 lines] > > See the problem? No, at least nothing compared to the problem of paying $30 billion a year -- soon to be $100 billion/yr -- for diesel used in agriculture. Bret Cahill >On Jul 21, 10:45?pm, John Larkin ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: [quoted text clipped - 21 lines] >No, at least nothing compared to the problem of paying $30 billion a >year -- soon to be $100 billion/yr -- for diesel used in agriculture. --- Avoiding the issue by changing the subject, are we??? And here just a couple of post ago you mentioned that you play by the honor system. Well, now that we see that you're also a liar let me give you a little clue as to how some of this here elecktrickle stuff works: If a battery with a capacity of 2 AH (120 ampere-minutes) needs to be recharged in two minutes, then you've got to fill it back up with the same amount of electricity, but you've only got 2 minutes to do it in, so you've got to pump it in faster than it came out. 60 times faster, in fact, so that means instead of 2 amperes going in you've got to force 120 amperes into that poor little AA battery. BIG problem! Actually, because of losses, you'd have to pump more than that into it to fully charge it and, just as an aside, the capacity of the battery is usually rated at C/10 or C/20 which means that, for a 2AH battery, the rate of discharge in order to achieve full capacity would be, in the first case, 200mA for 10 hours and in the second case, 100mA for 20 hours. JF >>On Jul 21, 10:45?pm, John Larkin >><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: [quoted text clipped - 47 lines] > >JF Hey, John, don't confuse the poor guy with a lot of math and technology. Usenet is a magnet for amateurs with looney ideas. John > >> >Not that pausing a few minutes is a problem either but a fast > >> >recharging battery just isn't a serious issue. [quoted text clipped - 19 lines] > --- > Avoiding the issue by changing the subject, are we??? The Issue has _always been_ liquid fuel costs. There is no reason to electrify the farms if diesel wasn't spiraling. . . . > If a battery with a capacity of 2 AH (120 ampere-minutes) needs to be > recharged in two minutes, then you've got to fill it back up with the > same amount of electricity, but you've only got 2 minutes to do it in, > so you've got to pump it in faster than it came out. � And it "came out" in 6 - 10 minutes. The tractor is moving 6 - 10 mph. Alternatively, if the tractor is moving slowly, then it won't require 400 hp, and you'll _still_ have a short charging time. You keep trying to dodge the fundamental reason this is a better application of batteries than the wildly popular plug in hybrids: Unlike EVs or plug ins the tractor never goes very far from the charger. The batteries can therefore be small and cheap and have short charging times. And we haven't gotten to the favorable torque/rpm curve of electric motors which allows a much smaller hp motor. Bret Cahill >And we haven't gotten to the favorable torque/rpm curve of electric >motors which allows a much smaller hp motor. Didn't somebody already invent gears? John > >And we haven't gotten to the favorable torque/rpm curve of electric > >motors which allows a much smaller hp motor. > Didn't somebody already invent gears? You _want_ to go Rube Goldberg? If your goal is to cost farmers more money then that explains a lot. Bret Cahill >> >And we haven't gotten to the favorable torque/rpm curve of electric >> >motors which allows a much smaller hp motor. [quoted text clipped - 6 lines] > >Bret Cahill Tell us about your farming experience. John >> >And we haven't gotten to the favorable torque/rpm curve of electric >> >motors which allows a much smaller hp motor. [quoted text clipped - 4 lines] > >If your goal is to cost farmers more money then that explains a lot. --- So you don't even understand the function of a transmission? _That_ explains a lot. JF >>> >And we haven't gotten to the favorable torque/rpm curve of electric >>> >motors which allows a much smaller hp motor. [quoted text clipped - 11 lines] > >JF Tee-hee, imagine an electric motor coupled directly to the drive wheels of a tractor. John >>>> >And we haven't gotten to the favorable torque/rpm curve of electric >>>> >motors which allows a much smaller hp motor. [quoted text clipped - 14 lines] >Tee-hee, imagine an electric motor coupled directly to the drive >wheels of a tractor. --- Not to add fuel to Brat's fire, but... Big-a.s PWM controller? JF >>>>> >And we haven't gotten to the favorable torque/rpm curve of electric >>>>> >motors which allows a much smaller hp motor. [quoted text clipped - 17 lines] > --- > Not to add fuel to Brat's fire, but... Big-a.s PWM controller? The problem is getting enough torque at the low RPMs. It might be possible to design a really large wheel motor with, say, 64 poles, that would run at 112 RPM at 60 Hz, but a really large wheel would still not have enough torque to meet the requirements. Gears or some other speed reduction mechanism are definitely needed for a tractor. Hydraulic motors are a possibility, but they are probably not as efficient as a well made gear train. Tractor transmissions are already well-defined for an engine with about 1800 to 3600 RPM, so an electric motor would be an easy direct fit. Paul >>>>>> >And we haven't gotten to the favorable torque/rpm curve of electric >>>>>> >motors which allows a much smaller hp motor. [quoted text clipped - 22 lines] >112 RPM at 60 Hz, but a really large wheel would still not have enough >torque to meet the requirements. --- Good point. --- >Gears or some other speed reduction >mechanism are definitely needed for a tractor. Hydraulic motors are a [quoted text clipped - 3 lines] >Tractor transmissions are already well-defined for an engine with about >1800 to 3600 RPM, so an electric motor would be an easy direct fit. --- That's interesting in that the motor could run at a more or less constant, efficient speed, powered by AC mains, and transfer power to the wheels or to the PTO via electronically controlled transmissions. What about the size of the motor and cooling requirements VS those for an ICE? JF >>The problem is getting enough torque at the low RPMs. It might be >>possible [quoted text clipped - 22 lines] > What about the size of the motor and cooling requirements VS those for > an ICE? An AC induction motor exhibits a fairly flat torque curve from something like 10% of design RPMs at 50/60 Hz, and then is usually shown as decreasing, because, although motors can be driven by PWM to several times their rated speed, it is not usually recommended (or feasible) to increase the voltage accordingly (as a VF drive does). But there is nothing "magic" about 60 Hz as a limit for the magnetics, and it is possible to design motors that run up to at least 400 Hz. They are typically very high RPM, but with enough poles, it is possible to boost the HP of a motor by several times, using lower voltage windings and running at least up to 150 Hz. You can get 2 or three times the HP from the same size motor. This is very important for highway vehicles, where the weight and size of the motor contribute a lot to fuel economy and performance, but probably not as much for a tractor, where additional weight might be a good thing. Since large induction motors are typically 92 to 95% efficient, a 75 kW 100 HP motor will produce something like 5000 watts of heat, which is removed by means of self-contained fans. A motor specially designed to be overdriven might be even more efficient, although there is a limit where magnetic losses take over. The good thing about electric motors is that they consume no power when they are idle, and their losses are at worst a percentage of the actual output power, and may even be less when lightly loaded. Losses are proportional to I^2, while torque is proportional to I. They can also be "pushed" to 2 or 3 times their nameplate ratings for short periods of time, so you can often get by with a smaller motor if your power needs are intermittent. So the transmission requirements are mostly to provide the needed torque, and then the motor speed can be adjusted as needed. Large tractors probably have trannies with 10 or 15 speeds or more, while an electric motor might require only 3 or 4. This would be another saving. VF drives are so efficient and inexpensive now, that any other motor controller is just about unthinkable. And you can run a VF drive on 720 VDC directly, so it is ideally suited to a battery pack for use when transferring from one power source to another. This would require much less power than the tractor is actually rated for, so the battery pack could be quite small. Paul .... > > That's interesting in that the motor could run at a more or less > > constant, efficient speed, powered by AC mains, and transfer power to [quoted text clipped - 40 lines] > > Paul Paul, On behalf of sci.energy readers, THANKS for a great overview of electric motor basics. Very seldom do we see postings of this quality, and I at least very much appreciate that. Thanks again Rob >.... >> > That's interesting in that the motor could run at a more or less [quoted text clipped - 54 lines] >Very seldom do we see postings of this quality, and I at least very much >appreciate that. It always impresses me that a lot of people participate in specialty newsgroups, and have opinions about technology and public policy, without making any effort to read a few books and understand the basics of what's actually going on, or the quantitative limits of what's possible. My wife wanted me to put a windmill on our roof to make our own electricity. John >>>The problem is getting enough torque at the low RPMs. It might be >>>possible [quoted text clipped - 58 lines] >source to another. This would require much less power than the tractor is >actually rated for, so the battery pack could be quite small. --- Very nice. :-) Thanks! JF > Tractor transmissions are already well-defined for an engine with about > 1800 to 3600 RPM, so an electric motor would be an easy direct fit. I think we are really just arguing about the mythic lightweight super capacity battery pack and or the relative cost of the massive central pivot power supply, not to mentin the $AUSX00,000 is going to charge you to bring in an 11Kv feed. <imagine the speed of the outside support of a central pivot supply as the tractor ploughs the inner rings {:-)> >>>>> >And we haven't gotten to the favorable torque/rpm curve of electric >>>>> >motors which allows a much smaller hp motor. [quoted text clipped - 19 lines] > >JF Unless the thing was 8 feet in diameter (which would have its own problems) you'd need kiloamps of coil current and megagauss field strengths to get the kind of torque a tractor wheel would need. This guy is as ignorant of electrical and mechanical engineering as he is of farming. John >> >> >Not that pausing a few minutes is a problem either but a fast >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 21 lines] > >The Issue has _always been_ liquid fuel costs. --- Sorry, Charlie, nice try but the issue at the moment, brought up by JL, is whether you can appreciate the economics of battery charging. You're obviously clueless and decided to side-step by changing the subject. No matter, I'll explain it to you a little later on and then you can claim you knew it all along, OK? --- >There is no reason to electrify the farms if diesel wasn't spiraling. --- Blah, blah, blah... --- >> If a battery with a capacity of 2 AH (120 ampere-minutes) needs to be >> recharged in two minutes, then you've got to fill it back up with the [quoted text clipped - 4 lines] > >The tractor is moving 6 - 10 mph. --- So how long would you want to wait for the battery to charge up? One minute? you'd still have to pump in at least 6 times as much current as came out. For 400 horsepower, the power into the motor would be: 400HP * 746W P = ------------- = 298 400 watts HP and the current required from a 300V battery pack would be: P 298 400W Iout = --- = ---------- ~ 995 amperes E 300V Therefore, if you ran the machine for six minutes and recharged it for one, The current into the battery would have to be: Iout * Tout 995A * 360s Iin = ------------- = ------------- = 5970 amperes Tin 60s Typically, to charge a battery fully you've got to put in 1.4 times as much energy as you took out, which would increase that 5970 amperes to about 6400 amperes. Now, when you consider that that electricity has to come from _somewhere_ and that is has to be brought into the field using conductors of finite resistance, then the problem becomes even more severe. --- >Alternatively, if the tractor is moving slowly, then it won't require >400 hp, and you'll _still_ have a short charging time. --- You were the one who stipulated 400HP and now you're back-pedaling? Typical trick for someone who doesn't know what he's talking about to try to get off the hook. --- >You keep trying to dodge the fundamental reason this is a better >application of batteries than the wildly popular plug in hybrids: --- Me??? All I've done is taken numbers that you've supplied and shown you why what you advocate is impractical. You, on the other hand, keep trying to move the goal posts in order to try to make your position seem tenable. --- >Unlike EVs or plug ins the tractor never goes very far from the >charger. --- It doesn't make any difference. Coulombs is coulombs and if you want to fill a battery up in 1/10th the time it took to discharge it you'll have to pump in ten times as much current during that time. More, even, because there's no free lunch. See above. --- >The batteries can therefore be small and cheap and have short charging >times. --- How small? How cheap? How short a charging time? You obviously have no clue and know _nothing_ about battery chemistry. --- >And we haven't gotten to the favorable torque/rpm curve of electric >motors which allows a much smaller hp motor. --- As if you knew anything about it before another poster bought it up. Get on with it, then. Let's see your analysis. JF > Typically, to charge a battery fully you've got to put in 1.4 times as > much energy as you took out, which would increase that 5970 amperes to > about 6400 amperes. Err, is this something to do with fast charging? Heard 110% for C/10 in dep-discharge lead acid batteries, but not that much. >> Typically, to charge a battery fully you've got to put in 1.4 times as >> much energy as you took out, which would increase that 5970 amperes to >> about 6400 amperes. > >Err, is this something to do with fast charging? --- No, it's the typical coulometric charge-discharge characteristic of a flooded lead-acid battery. --- >Heard 110% for C/10 in dep-discharge lead acid batteries, but not that >much. --- It can go higher for SLAs, according to: http://www.powerstream.com/SLA.htm JF > It can go higher for SLAs, according to: > > http://www.powerstream.com/SLA.htm Well, I guess I won't be ever buying their batteries then. >> It can go higher for SLAs, according to: >> >> http://www.powerstream.com/SLA.htm > >Well, I guess I won't be ever buying their batteries then. --- I can't imagine why not. What do find wrong with them? JF >>> It can go higher for SLAs, according to: >>> [quoted text clipped - 6 lines] > > What do find wrong with them? Requiring 140% of C put back in to get C back out. > JF >>>> It can go higher for SLAs, according to: >>>> [quoted text clipped - 8 lines] > >Requiring 140% of C put back in to get C back out. --- That's typical for _any_ flooded lead-acid battery, while much higher efficiencies can be enjoyed by using SLAs. Including theirs, I suppose. From their site, under BASICS: "The coulometric charging efficiency of flooded lead acid batteries is typically 70%, meaning that you must put 142 amp hours into the battery for every 100 amp hours you get out. This varies somewhat depending on the temperature, speed of charge, and battery type. Sealed lead acid batteries are higher in charge efficiency, depending on the bulk charge voltage it can be higher than 95%." JF > That's typical for _any_ flooded lead-acid battery, while much higher > efficiencies can be enjoyed by using SLAs. Including theirs, I > suppose. Conflicts with other stuff I've read claiming 110%. notie this paragraph after I flicked the other answer.... > Now, when you consider that that electricity has to come from > _somewhere_ and that is has to be brought into the field using > conductors of finite resistance, then the problem becomes even more > severe. So instead of 415V supply, you just tap the 11Kv lines instead. >notie this paragraph after I flicked the other answer.... > [quoted text clipped - 4 lines] > >So instead of 415V supply, you just tap the 11Kv lines instead. --- How would you do that? JF >>notie this paragraph after I flicked the other answer.... >> [quoted text clipped - 7 lines] > --- > How would you do that? You throw a wire over it. Just make sure to wear rubber gloves :o) >>>notie this paragraph after I flicked the other answer.... >>> [quoted text clipped - 9 lines] > >You throw a wire over it. Just make sure to wear rubber gloves :o) --- ;) JF >>notie this paragraph after I flicked the other answer.... >> [quoted text clipped - 7 lines] > --- > How would you do that? Sigh. Basics of electrical pwer distribution; distrubte in as high a voltage as you can to reduce current being moved,then transform down for local requirements.> AFAIK, 11Kv is the next step up from 415V supply. > JF >>>notie this paragraph after I flicked the other answer.... >>> [quoted text clipped - 11 lines] >voltage as you can to reduce current being moved,then transform down for >local requirements.> AFAIK, 11Kv is the next step up from 415V supply. --- Very good! You, at least, seem know what you're talking about. :-) JF > >> >> >Not that pausing a few minutes is a problem either but a fast > >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 25 lines] > Sorry, Charlie, nice try but the issue at the moment, brought up by > JL, is whether you can appreciate the economics of battery charging. Still trying to dodge the OP issue, the cost of diesel fuel? Are you just acting dumb or are you really this stupid in real life? Bret Cahill On Thu, 24 Jul 2008 12:47:24 -0700, BretCahill wrote: > Still trying to dodge the OP issue, the cost of diesel fuel? Seriously, it isn't really ever an issue because oce you start looking at the alternatives, it just beats them hands down. Now, at about $1,000/barrel, it might be a big issue. >> >> >> >Not that pausing a few minutes is a problem either but a fast >> >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 27 lines] > >Still trying to dodge the OP issue, the cost of diesel fuel? --- Nope, the cost of diesel fuel is what it is and your lunatic raving isn't going to change it. My point was and is that your hare-brained electric tractor scheme is impractical and economically unviable at this time. --- >Are you just acting dumb or are you really this stupid in real life? --- Neither. JF > >> If a battery with a capacity of 2 AH (120 ampere-minutes) needs to be > >> recharged in two minutes, then you've got to fill it back up with the [quoted text clipped - 7 lines] > --- > So how long would you want to wait for the battery to charge up? > One minute? you'd still have to pump in at least 6 times as much > current as came out. Which is trivial merely by wiring in more batteries in parallel. Are you just acting dumb or are you really this stupid in real life? . . . > >Alternatively, if the tractor is moving slowly, then it won't require > >400 hp, and you'll _still_ have a short charging time. > You were the one who stipulated 400HP The real savings appear in the energy intensive operations. The more energy intensive the operation, the bigger the savings from moving from diesel to batteries. If you go to less energy intensive operations, say a garden tractor, it is of course cheaper to go Li-Ion instead of liquid fuel, but the absolute savings aren't all that great. Are you just acting stupid or are you really a moron in real life? Bret Cahill > >> >Not that pausing a few minutes is a problem either but a fast > >> >recharging battery just isn't a serious issue. [quoted text clipped - 19 lines] > --- > Avoiding the issue by changing the subject, are we??? _You_ not "we." The original issue was _always_ the $100 billion wasted on diesel. Bret Cahill >> >> >Not that pausing a few minutes is a problem either but a fast >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 23 lines] > >The original issue was _always_ the $100 billion wasted on diesel. Who wastes $100b a year on diesel? John >> >> >Not that pausing a few minutes is a problem either but a fast >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 23 lines] > >The original issue was _always_ the $100 billion wasted on diesel. --- But it's not the issue presently, what is is whether you understand the economics of battery charging. You obviously don't and changed the subject in order to skirt it. JF > >> >> >Not that pausing a few minutes is a problem either but a fast > >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 16 lines] > >> >No, at least nothing compared to the problem of paying $30 billion a > >> >year -- soon to be $100 billion/yr -- for diesel used in agriculture. > >> Avoiding the issue by changing the subject, are we??? > >_You_ not "we." > >The original issue was _always_ the $100 billion wasted on diesel. > But it's not the issue presently, The cost of liquid fuel compared to grid-battery is the only reason to discuss the electric tractor. If you try to weasel out of the relative cost of diesel vs grid- battery everyone will know you're a loser as well as a moron. > what is is whether you understand > the economics of battery charging. � There is one reason and one reason only to discuss the cost of grid- battery energy: To compare it with diesel. To win this debate you'll need to show how diesel power is cheaper than charging batteries and running an electic motor off them. You cannot so you will try to dodge the issue of diesel costs altogether. Bret Cahill > To win this debate you'll need to show how diesel power is cheaper > than charging batteries and running an electic motor off them. Oh, how do I find your figures? >To win this debate you'll need to show how diesel power is cheaper >than charging batteries and running an electic motor off them. > >You cannot so you will try to dodge the issue of diesel costs >altogether. --- Since I've shown that your harebrained scheme is impractical and unworkable and that diesel is here and working 24-7-365, no matter what its cost, I've already won. If you want to prove that your system is viable, and superior to diesel, then you'll need to show why it's cheaper than diesel overall, not just in the cost of fuel. But you can't do that, so all you do is keep trying to muddy the waters in order to keep from looking like a fool. Guess what? It's not working. JF > >> >Not that pausing a few minutes is a problem either but a fast > >> >recharging battery just isn't a serious issue. [quoted text clipped - 19 lines] > --- > Avoiding the issue by changing the subject, are we??? The OP issue is the tens of billions a year unnecessarily wasted on diesel for agriculture. That's the context, the _only_ reason for electrification of farms. Are you just acting dumb or are you really this stoopid? Bret Cahill On 7/24/08 12:39 PM, in article fbdc4423-0fc6-4476-a17d-2eda457c8ecb@i20g2000prf.googlegroups.com, >>>>> Not that pausing a few minutes is a problem either but a fast >>>>> recharging battery just isn't a serious issue. [quoted text clipped - 26 lines] > > Are you just acting dumb or are you really this stoopid? Since you persist in being an obstinate mule regarding proper posting form, I don't know to whom you are responding or addressing. IMHO you are the stupid one for posting this off-topic crap to the s.e.b. Newsgroup. > Bret Cahill >> >> >Not that pausing a few minutes is a problem either but a fast >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 22 lines] >The OP issue is the tens of billions a year unnecessarily wasted on >diesel for agriculture. --- Hardly 'wasted', since it's used to provide us and many other people in the world with food. And hardly 'unnecessarily', since there is no alternative at this time. Your suggestion, no matter how vociferously you defend it is unworkable and we all have to eat, so the tractors will continue to run on diesel, whether you like it or not. --- >That's the context, the _only_ reason for electrification of farms. --- If the time comes when it'll be economically feasible to farm electrically, then it'll happen. Your lunatic raving, BTW, will really have no effect on when that happens, and if you seriously want to see change then you should get to work figuring out how to make it happen instead of just flapping your jaws spewing idiocy. --- >Are you just acting dumb or are you really this stoopid? --- Neither. JF >On Jul 21, 10:45?pm, John Larkin ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote: [quoted text clipped - 23 lines] > >Bret Cahill Ah, the $100b is "soon to be." The number didn't make sense; in the US, I figured farmers are currently running around $20b a year for diesel. More is probably spent on transporting the products after they leave the farm. Crude oil is down to $124 today. John >Not that pausing a few minutes is a problem either but a fast >recharging battery just isn't a serious issue. > >All that is necessary is make the cells smaller. > >The smaller the cell, the faster the recharge. --- And the more expensive the finished battery cost per watt-hour. --- JF > >Not that pausing a few minutes is a problem either but a fast > >recharging battery just isn't a serious issue. [quoted text clipped - 5 lines] > --- > And the more expensive the finished battery cost per watt-hour. The tractor only goes a mile between charges so a tractor battery doesn't need a lot of watt-hours / work done. The initial cost of a production run electric tractor drive train would be less than a diesel tractor. Any argument for plug in hybrids is an *a fortiori* argument for the grid-battery "hybrid" tractor. Bret Cahill >> >Not that pausing a few minutes is a problem either but a fast >> >recharging battery just isn't a serious issue. [quoted text clipped - 8 lines] >The tractor only goes a mile between charges so a tractor battery >doesn't need a lot of watt-hours / work done. --- Really? Your 400 horsepower tractor, working for an hour, would need a battery which can supply about 300KWH, (300 000 watt-hours) and if it's doing it with an output voltage of 300V that means it needs to be rated for an output of 1000AH at C/1. That's a lot of watt-hours and a lot of work done. --- >The initial cost of a >production run electric tractor drive train would be less than a >diesel tractor. > >Any argument for plug in hybrids is an *a fortiori* argument for the >grid-battery "hybrid" tractor. --- Poppycock. JF > >> >Not that pausing a few minutes is a problem either but a fast > >> >recharging battery just isn't a serious issue. [quoted text clipped - 13 lines] > > Your 400 horsepower tractor, working for an hour, It takes a hour to get across a field? What farming operation requires 400 hp to go 0.5 mph? . . . > >Any argument for plug in hybrids is an *a fortiori* argument for the > >grid-battery "hybrid" tractor. > Poppycock. Now that shows some thought. Bret Cahill >> >> >Not that pausing a few minutes is a problem either but a fast >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 17 lines] > >What farming operation requires 400 hp to go 0.5 mph? --- Hey, its _your_ number, genius... --- >. . . > [quoted text clipped - 4 lines] > >Now that shows some thought. --- Junk in, Junk out. JF > >> >> >Not that pausing a few minutes is a problem either but a fast > >> >> >recharging battery just isn't a serious issue. [quoted text clipped - 13 lines] > > >> Your 400 horsepower tractor, working for an hour, > >It takes a hour to get across a field? Notice the dodge? > >What farming operation requires 400 hp to go 0.5 mph? > > --- > Hey, its _your_ number, _You_ are the moron who thought it would take an hour to get across the field. _My_ number was 6 - 10 minutes to get across the field and back between charges, _much_ less time than that expected of an EV or plug in battery. The more you try to be too clever by half the dumber you're gonna look. > >> >Any argument for plug in hybrids is an *a fortiori* argument for the > >> >grid-battery "hybrid" tractor. > > >> Poppycock. Well? Don't keep us settin' on the edges of our chairs. Either tell us why plug in hybrids are a waste of money or how the grid-battery tractor is fundamentally different than a plug in hybrid. But don't just sit there and whine. Bret Cahill > It takes a hour to get across a field? > > What farming operation requires 400 hp to go 0.5 mph? See, you don't know anything about farming. I'll bet you thought they plow at 60 MPH. Signaturehttp://improve-usenet.org/index.html If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm Sporadic E is the Earth's aluminum foil beanie for the 'global warming' sheep. > > It takes a hour to get across a field? > > > What farming operation requires 400 hp to go 0.5 mph? > > � �See, you don't know anything about farming. I ask a question and you dodge it. Here, we'll try again: What farming operation requires 400 hp to go 0.5 mph? If you dodge again the only assumption is you are ignorant of farming operations. >�I'll bet you thought > they plow at 60 MPH. Well you lost that bet. The record shows I always assumed a speed of 6 - 10 mph and that the round trip would take 6 - 10 minutes, much less time that the charge expected for an EV or plug in. Bret Cahill |
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