300 kW EV Tractor vs 400 hp Diesel

The Tesla is powered by 7,000 Li-Ion laptop batteries for an output of

200 kW.

A similarly powered 300 kW electric tractor (10,500 batteries) would turn a 400 hp articulated 22 gallon/hour diesel tractor every which way but loose in a tractor pull which apparently is vitally necessary education as well as entertainment for those too ignorant do basic IEOR calculations.

Running either tractor wide open to work a square mile at 0.5 mph would take 3 months of 7 day work weeks at 8 hours / day.

It would also require 17,000 gallons of diesel.

Today the cost is "only" $80,000 for the diesel.

In 2 years, with the price of hydrocarbon fuel spiraling by 30% a year, that cost will be $150,000/yr.

In six years the cost of the fuel will be half a million dollars.

And that's just for one field.

Maybe if we have massive truck and bus conversion to natural gas -- include farm tractors in Pickens plan -- the price will "only" be $350,000/field in 6 years.

The battery tractor would be cheaper even if grid power tripled and even if you went to your overpriced Apple Inc. store and bought the batteries one by one and wired them together one by one yourself.

Now, if you don't believe laptop batteries exist, please go to alt. conspiracy and post there.

Bret Cahill

Reply to
BretCahill
Loading thread data ...

I think your numbers are off.

Extrapolating from table 2 at this URL,

formatting link
I guestimate it'll take roughly 1,075 gallons of diesel to plow a square mile 8 inches deep, and take approximately 64 hours to do it using a 244 hp tractor.

Reply to
B Richardson

In that case we can get by with a much smaller battery.

My numbers were based on those provided by some "expert" claiming that was a farming operation that would take an hour to go half a mile and require 400 hp.

Bret Cahill

Reply to
BretCahill

For short periods of time.

Would be a failure as a tractor. One to two hours working time followed by several hours of recharge time? The Tesla is probably more at than 8 hours of recharge time.

Never drove a tractor, I see. If you are working at 0.5 miles per hour (about a km per hour), then you are not using anything close to 300 kW.. Soil resistance times speed equals power. I don't know of anything that would usually be done that slow, but there are crops I know little about, like cotton and peanuts. More usual speeds are 5 to 20 km per hour, and that is pulling a disk harrow 6 to 8 meters wide or wider, and working 20 cm deep. Planting takes less power. Harvesting is done with different machinery.

Ah, here is a bit of amusement for you.

formatting link
Converting units is such a pain, but if I did it correct 905ha is 2200 acres or 3.5 square miles planted in 24 hours. How wide is that rig in the picture? I'd guess 16 meters. How fast were they pulling that?

Reply to
phil hays

Show me. Get one in the field for long enough to find out battery replacement costs and such what costs. Build a recharger, and find out what sort of power the REA will deliver. No offense, but

And don't forget:

The alternative isn't just diesel, it is also biodesel and other biofuels.

So how much will the wood for a steam tractor run?

Reply to
phil hays

Buy two Teslas for $100K each then scrap them for the motors and batteries.

Already you've saved money compared to the diesel, maybe even in initial cost alone!

Every cost is _already_ well known and can be easily calculated by any IEOR.

What next? Reinvent the wheel?

And you're whining about about battery technology being unproven?

? ? ?

We _know_ everything about the batteries. They already exist. We only have _claims_ for the algae.

Not nearly negative enough to pay for the time you'll spend scraping the creosote, slag, ash, tar and other carcinogic crap off the 1/2 mile of fire tubing.

What's wrong with burning bio at a utility power plant set up to burn bio?

A pizzeria is set up to make pizza.

A farm is set up to cultivate fields with grid power.

And a stationary power plant is set up to make power from bio.

Read the _Republic_ where each person does a specific task.

Bret Cahill

Reply to
BretCahill

Reply to
John Fields

Reply to
John Fields

IMO You have been less than ethical in your posts. Why would anyone care if CBS beat you to something/

Reply to
Don Bowey

Diesel will not keep rising at 30%. The only reason that it is not already falling is that the lead time on making synthetic diesel from coal is long and the initial capital investment is high, so noone has taken the plunge. However, if the costs threaten to keep rising, it will be done, as there are still huge reserves of coal and someone stands to make a huge pile of money supplying cheaper energy.

Reply to
rlbell.nsuid

Plant alternate rows with this:

formatting link
and the steam tractor could harvest its fuel as it performs its function. Candelilla burns quite well because of its high wax content. In Mexico, peasants harvest wild candelilla and boil it to extract the wax. The leftover stalks are then burnt as fuel for boiling more candelilla.

Reply to
Mark Thorson

I didn't come up with _any_ of the numbers here except the 6 - 10 mph speeds for the tractor, numbers that have been confirmed by another poster citing figures from a government web site.

I got the 400 hp along with the 22 gallons/hr from the local Case dealership. The biggest savings come from the biggest slurpers of diesel.

Some vineyard selling overpriced wine is _not_ going to be my first customer.

And I got the 0.5 mph from some too-clever-by-half poster claiming that some farming operation would take an hour to go half a mile running the 400 hp tractor wide open.

So you are boxed in.

If you claim that an operation requires a lot of energy, you are arguing against the diesel tractor because the diesel will need to consume so much $$$ to do an equivalent amount of work it's cheaper to buy the laptop batteries.

If you claim that the operation doesn't require much diesel, then you are also arguing for electric tractors because the battery pack will be so small.

You don't need a spreadsheet to figger out the EV tractor will _always_ be more cost effective than the diesel.

Take initial cost including whatever watt hour of batteries you think it'll need. Take the time paying the tractor driver to pause 2 minutes at the end of the field

Then do the operating costs including grid costs and diesel fuel costs _for the same operation_. I know you will try to dodge this one because this is the reason diesel is no longer competitive.

Then compare the overall costs just like any sophmore IEOR student.

Bret Cahill

Reply to
BretCahill

There's nowhere close to that much tubing. And all of that stuff would be burnt off at the operating temperature.

You originally tried to dismiss the steam tractor with the spectre of boiler explosions, which are a non-issue for firetube boilers.

When that failed, you retreated to this equally bogus argument. You don't know the facts, and try to dismiss what you don't know with hand-waving.

Steam has been practical for powering tractors in the past, and with modern materials it could be even more competitive. Best of all, it is the ultimate flex-fuel vehicle, because the fuel doesn't need to burn at a precise rate under confinement. It doesn't even need to be a liquid. It could even be coal (our most abundant fuel), or wood (our most abundant renewable fuel).

It's far more practical than hauling 10 tons of batteries around. It's also more efficient because it only converts chemical energy into mechanical work. The battery-powered tractor requires converting chemical energy into mechanical work (at the power plant), converting mechanical work into electricity (at the power plant), transmission line losses, converting electricity into chemical energy (charging the tractor's battery), converting chemical energy into electricity (discharging the battery), and converting electricity into mechanical work. You lose energy at every conversion step. Game over. Not practical.

Reply to
Mark Thorson

True. It will probably start increasing at 40% - 50% a year as the big wells give out lowering world production by a third in 8 years.

Far worse than the supply curve is the demand curve. China's double digit growth rate means it will pass the U. S. in as little as 6 years, probably earlier if Soros is correct about the permanent U. S. recession. Toss in India and the U. S. share of the global oil pie will plummet.

Unlike 1929 the entire country is wired. The media cannot deceive/ dumb down anywhere nearly as effectively as before. The Fed knows this and will want to keep unemployment as low as possible to keep the frog from jumping out of the pot. The dollar will get even weaker which will cause the price of oil to spiral even more.

The state of denial about the peak oil + China + the U. S. economy is understandable.

It's a bleak situation.

How long will _this_ take?

What about the interim? Are we just going to "load shed" millions of people?

It would be more cost effective to burn the coal in a power plant and power the tractors from the grid.

Even the electric tractor, much faster than coal liquification or even bio diesel, will take several years.

Bret Cahill

Reply to
BretCahill

Farmers are already paying people to sit in trucks 7.2 hours out of a

12 hour day to go through customs at the border.

Why not save money by having them sit in electric tractors in the field instead?

After all, the diesel costs $110/hour -- close to $200/hour in two years -- so there is plenty of savings to pay the tractor operator.

Anyways I'm still waiting for one single authority, any web page -- anything -- that claims that battery recharge times will not continue to drop.

=2E . .

Who suggested it was?

Anyway you dodged the issue.

The Tesla charger was for the typical household, not an industrial or farm application.

Never heard of electrified rail? Compared to a 10 minute 400 hp tractor recharge that would be 30X more power just for one locomotive.

Are you just acting dumb or are you really this stupid in real life?

Bret Cahill

Reply to
BretCahill

Then it ain't 400 hp.

That's a pipe dream.

=2E . .

That's the point of the trolly wire. The size of the battery can be reduced by 1 - 2 orders of magnitude because, unlike an EV or plug in, the tractor charges up every 6 - 10 minutes, after each pass.

A Tesla equivalent battery will work in most applications, very light for a tractor.

The capital cost would in the long run be even lower.

Not nearly as efficient as a real power plant burning bio.

Bret Cahill

Reply to
Bret Cahill

Bret, if the tractor goes (what was it?) 1 mph or so, and it needs 10 minutes for one pass (5 min each way), then the field is no wider than 440 feet. Is that a reasonable assumption ?

If so, why not just use a high-voltage extension cable ?

Actually, a 10kV line can be miles long without too many losses (for the 300 kW that you need).

Rob

Reply to
Rob Dekker

Some moron put the 0.5 mph figure. According to some government or industry site posted here, for almost all operations, the tractor is moving 6 - 10 mph.

300 kW that you need).

The cheapest system is a 1/2 mile long wire and a Tesla sized battery.

Bret Cahill

Reply to
Bret Cahill

utes for one pass (5 min each way), then the field is no

No. As one poster citing government and industry material pointed out, tractors generally go much faster.

Another moveable wire off of the stationary wire?

300 kW that you need).

Losses aren't an issue.

Bret Cahill

Reply to
Bret Cahill

Wasted money unnecessarily tying up the driver's and truck's time.

=2E . .

That you are dodgin' 'n dodgin'?

OK, now that you twisted my are, I admit it.

You are dodgin' 'n dodgin'.

=2E . .

Is there any reason to believe it isn't?

=2E . .

=2E . .

Then we'll need to start building prototypes as soon as possible to accomodate the new batteries.

"Huge?"

Science has been quantitative since Galileo

Anyway those "huge" currents are 1/30th those of an electric locomotive.

=2E . .

=2E . .

The Tesla charger was for the typical household, not an industrial or farm application.

Notice the dodge?

Can you tell us what you think is a pertinent difference?

Maybe you just jumped in on the wrong side and now cannot admit you were wrong.

Bret Cahill

Reply to
Bret Cahill

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.