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Re: (ET) fuel costs



Robert - no argument with anything you said in your reply.  It would be interesting to study the "cost/benefit"  analysis of, say, a diesel engine tractor vs an electric is a holistic sense.  The diesel fuel is densely "packed" energy per pound, more so than the power stored in a lead-acid battery in particular.  However, the electric motor is lighter than the diesel and has the most torque at stall, which is ideal for a tractor application.   I have seen only home-built attempts at larger agricultural electric tractors, say the size of my 40 hp diesel 4wd utility.  Why?  I suspect that the battery pack needed would bury the tractor.  I suspect that in smaller (lawn) tractors, electric might be more efficient overall (including the weight of the motors and "fuel tank"), but at some point on the larger size spectrum the usefulness of electrics fall off by comparison to small diesels.

 

I have an E-15 with a bucket loader run by hydraulic-electrics, and use it to load gravel out of a pile and into carts for trail maintenance.  Two things become obvious doing this: (1) When you start running heavy power load accessories like the loader or a snowblower, run time for the ET gets shorter fast and (2) It sucks to exhaust your batteries out in the woods.  I have to transport my ET by trailer to and from the job site frequently for recharges, and have considered the addition of a solar charging station - which seems very expensive at a size that would be effective.  It's easier to move 5 gallons of diesel in a can to the tractor.

 

My conclusion:  ET's are well suited to suburban lots where they can enjoy proximity to an outlet and relatively light power loads (like lawn mowing).  Yes - I know the ET snowblower or tiller sucks up power like a sponge but is still useful.   My loader does too.  It was used for materials handling in a yard of an industrial firm (with lots of outlets).  Unless there are major advances in battery technology that allow the storage of as much energy per pound of fuel tank as a hydrocarbon powered machine, I don't see a big off lawn market for electric tractors.

 

 

From: Robert [mailto:euclid delhitel net]
Sent: Monday, January 07, 2013 8:39 AM
To: elec-trak cosmos phy tufts edu
Subject: Re: (ET) fuel costs

 

Pieter,

I know about diesel tractors, they are great! I have a JD 3320 with a 485 back hoe. I bush hog an 8 acre field for pennies BUT a couple of caveats. Don't ever blow a distributor pump on a diesel, the cost can run into the thousands, aside from that they are hard to beat for big jobs. To the credit of the ETs, they are made for smaller plots. My JD ztrak with a gas engine sucks up fuel, it's the hydo box, I would say to do about 2 acres it takes a gallon and a half of fuel, maybe a little more or a little less depending on the height of the grass. That job will be replaced by my ET when it's done. Also my wife is going to get and ET, she absolutely hates gas anything. I bought her a lith-ion weed whacker and she smiles every time she uses it. No starting problems like her mini tiller, low noise and she isn't blowing gas fumes all over our organic gardens. For smaller plots you just can't beat the ETs, what a great and well thought out machine! When ours are finished they will till the gardens, mow the lawns, blow snow and be charge by my 10.6 Kw solar array. I can't wait!

I think the important thing to consider is that the ETs compliment the tractor, neither replaces the other. Had we continued with electric technology in tractors this wouldn't be the case but then if we had stayed with electric cars the world would be a different place today too!

My four cents (adjusted for inflation)

Rob