Re: Grid-Battery "Hybrid" Tractors

On Thu, 24 Jul 2008 13:22:36 -0700, Bret Cahill wrote:


Huh, you want to encourage extreme peaks in demand for electricity?

There is, there is. I keep doing the figures on a battery car and every time, it is far cheaper to run a diesel car.
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On Thu, 24 Jul 2008 13:22:36 -0700 (PDT), Bret Cahill

--
Got some numbers?

JF

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On Thu, 24 Jul 2008 13:22:36 -0700 (PDT), Bret Cahill

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Then get off your lazy ass and build something to prove it.

JF

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Then to do just one square at 0.5 mph:
Diesel: 17,000 gallons.
Diesel cost today: $85,000
Assuming the price of liquid fuel continues to increase at "only" 30% a year:
Diesel cost in 2 years: $145,000
Diesel cost in 6 years: $425,000
And that's just one one time operation.
It's a whole lot cheaper to electrify, even if you have to buy 14,000 laptop batteries (twice that of the 200 kW Tesla) and install them yourself.
Bret Cahill
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On Wed, 23 Jul 2008 14:18:19 -0700, BretCahill wrote:

Actually, your system might work better if the tractor camewith a pair of swappable battery packs that you dock in and out of a charging station.
It would certainly help the economics by reducing the peak power demands.
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I mentioned that here last summer. It might take 2 - 3 dozen large expensive battery packs.
But I don't deny even that might eventually be more cost effective than diesel.
The cheapest fastest way to go now is the trolly wire - battery "hybrid."
Batteries can be wired in parallel for fast recharging. So the guy pauses a minute or so at the end of the field . . . no biggie. His job is to make money and he can no longer make money burning 2-oil.

If they are using lasers and GPS they can plow at night. TVA has 7 GW available at 7 cents / kW hr. at night, about 1/4th the cost of diesel power
The SW will soon have a lot of solar anyway.
Bret Cahill
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On Thu, 24 Jul 2008 13:36:18 -0700, Bret Cahill wrote:

Do you have any idea how much it will cost to put up that infrastructure and maintain it?
Crop farmers will just love that idea; massive bird perch for the seed eaters.

ROFPMP. You are just so hilarious. Have you done any maths on this matter?
Oh, do you know that all the existing fast charge batteries are liable to explode when fast charged?
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I like that idea a lot. Could maybe even have a separate battery 'wagon' that follows the tractor closely by itself (with a distance sensors and a small computer). The battery wagon can be plugged in an out very easily (without having to remove the battery from the tractor itself). Only problem might be that the mass of the tractor might no longer be enough for good traction. So maybe we should leave the old ICE in there :o)
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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
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On 7/24/08 12:39 PM, in article snipped-for-privacy@i20g2000prf.googlegroups.com,

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.

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On Thu, 24 Jul 2008 12:39:41 -0700 (PDT), snipped-for-privacy@peoplepc.com wrote:

--
Hardly 'wasted', since it's used to provide us and many other people
in the world with food.
  Click to see the full signature.
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Put out the shoe and the idiots step right in.

Did you miss the response?
That the more diesel the tractor burns the more cost effective it is to switch to battery-grid electric tractors?
Are you just acting dumb or are you really this dumb in real life?
Bret Cahill
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On Thu, 24 Jul 2008 13:39:59 -0700 (PDT), Bret Cahill

--
Up to your snip tricks again, huh?
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That's why the grid-battery "hybrid" is the most cost effective solution
The tractor never goes very far and can work with a relatively small battery, a couple of Teslas would be more than enough.
The small cell phone or lap top batteries wired in parallel would charge up in a couple of minutes.

Diesel power is already 3X more than grid power and the spiraling is _not_ going to stop.
A few percentage points in efficiency over spark ignition will not save diesel.

They waste tons idling at the end of a field.

Even EVs don't get much either, maybe 20% efficiency.

Sounds like the perfect application for an electric moror.

To drain money out of the farmer's pocket.

That's why the tractor is recharged each lap. It can get by with a relatively small battery.

Passenger vehicles don't have the option of getting recharged every 6 - 10 minutes.
The electric tractor is a much better application of batteries.

The driving range of a tractor is half a mile with the two wire system on a quarter square.

A tractor would be easy to prototype.
It's not like retolling a production line for a Prius or Volt.


The savings aren't significant.

I was planning for 6 - 10 an hour.
Every time the tractor makes it across the field or back it recharges.
Every time you decrease the time between charges you decrease battery cost and size.
Road vehicles do _not_ have this option.

Farmers find it acceptable to paying drivers $100 to sit at border crossings to buy diesel at $3/gallon.
Why not instead pay the tractor operator to sit at a line a couple of minutes after each pass?
Bret Cahill
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On Thu, 24 Jul 2008 14:17:54 -0700, Bret Cahill wrote:

Yep, that would have just made my day, when I was ploughing; do a lap of the paddock, disconnect plough, drive over to recharge point, connect up, make a cuppa whilst it recharged, disconnect, drive back to plough, reconnect plow, do another lap and repeat.
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Bret Cahill wrote:

Laptop batteries are typically good for about 1000 charges before becoming seriously degraded. Your hypothetical tractor would need a fresh set of batteries about every 2 weeks. You haven't taken this major cost into account.
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How would this cost be any different than the plug in hybrid or EV like the Tesla?
At least here the batteries are relatively small and replaced relatively often allowing for frequent upgrades.
I have yet to hear even one poster claim any knowledge of anyone in the battery industry or academia or any other authority who will not agree that battery technology is still improving fairly rapidly, energy density as well as recharge times.
Bret Cahill
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Bret Cahill wrote:

Because a car is only charged once or twice a day. If we assume an 8-hour shift, your tractor is being recharged 48-80 times a day. If this big, expensive tractor is used for multiple shifts, it could be much higher than that. You'll be producing mountains of dead, expensive batteries. There isn't enough hazmat landfill to handle them all.
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Please RECYCLE batteries. The metals in there are valuable (especially for lithium-based cells).
Although for tractors, you probably would not use Li-ions that are designed for small applications, although even these would already be economical (as Tesla shows). But for tractors, the low-cost, high energy density molten salt batteries (Zebra's, sodium/sulfur etc) are excellent :
http://en.wikipedia.org/wiki/Molten_salt_battery
Cheap, powerfull, thousands of cycles, and easy to recycle. With their high operating temperatures, these are rather 'clumsy' for small applications. But for tractors, busses and anything big, they should be great.
Rob
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On Thu, 24 Jul 2008 16:53:26 -0700, Rob Dekker wrote:

Low cost? I want a url to a price sheet. What is the energy density?
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