With custom harvesting where they start in Canada (or Siberia) with a new combine and work their way south through the season and sell the machine at the end, the logistics would not readily support tethering.
The combines may work with a semi-trailer driving along side to catch the resulting product, so much tonnage is harvested with wide decks that no hopper could possible hold it all on board the unit. I was working on controls for Deere harvesters in the mid 90's and they were trying to work out how to run 50 foot wide decks. Optimally you they would like to be able to hold in a hopper enough product to get up the row and back to unload and start again - if the trucks could not manage the side by side thing. Logistically a very trick product to design. They make these long decks so they can be tilted a couple different ways so they can stay at the exact correct height for maximum harvest. I got to drive one with a 36' deck cutting soybeans for a short time. Very interesting experience. These machines cost a million bucks plus and were worn out in one year. Or too worn for this magnitude of work. They can't have machines breaking down at all or they can't pay them off and make a profit too. In this sort of environment tethering sounds very hard to sell. Maybe for much smaller operations, but then the money available to spend on them is less. On Fri, Feb 21, 2014 at 1:21 PM, Peter Gabrielsson < peter.gabriels...@gmail.com> wrote: > Out of curiosity I looked up the diesel fuel consumption of Combines. It > ranges from 1-1.6 gallons per acre. Which roughly would translate to 12-20 > kWh of electricity per acre. So for a 100 Acre field you'd need 15 to 25 > tesla battery packs. Yikes. > > On the other hand you'd need a 1200 ft long cord for a 100Acre round field > presuming the center pivot is used. > > I bet those combines are already very efficient, running at a constant load > most of the time. There are some applications where using liquid dino fuels > just makes a ton of sense, large scale farming is probably one of them. > > > > > > > > On Fri, Feb 21, 2014 at 1:49 AM, Martin WINLOW <m...@winlow.co.uk> wrote: > > > Dear List, > > > > I was having a chat recently at work (which is nothing whatsoever to do > > with EVs!) about how vehicles that traditionally use lots of energy would > > ever be able to switch to electric power due to limitations on energy > > density. Fuel cell tractors came up amongst other things and then one of > > my colleagues who, on learning of the enormous amounts of power required > by > > combine harvesters and plough-pulling tractors, jokingly suggested using > 'a > > very long extension lead'. Whilst he is an ill-informed bumpkin, the > > thought did occur that in an agricultural context powering machines > > directly from the grid might not be so daft. I immediately thought of > > those enormous irrigation contraptions that work their way up and down > huge > > fields, laying and unlaying the hose that supplies the irrigation water > as > > it goes. Could not the same technique be applied to tractors etc? Each > > field would have a connection point with power brought in either above or > > below ground in the 'usual' way. > > > > An alternative idea would be to have mobile battery swap facilities > > connected to the grid in each field and be moved from field to field as > the > > work progressed. > > > > Just a thought! > > > > MW > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA ( > > http://groups.yahoo.com/group/NEDRA) > > > > > > > -- > www.electric-lemon.com > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140221/b05e4218/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com <michael.e.r...@gmail.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140221/468b1bf9/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)