Diesel vs gas

searcyfarms · Jul 16, 2018

yes but its gotten so expensive, no wonder it costs so much to fly with that jet fuel, my buddy gets jet fuel from the local law enforcement folks as if they don't use it all in a certain amount of time they have to get rid of it, I think they have regulations around shelf life or something and he mixes it with his diesel in his tractors - has been for years

Gale Hawkins · Jul 17, 2018

4570Man said:
Not any time soon.

This is the Fendt e1 Vario electric tractor - FutureFarming

Ahead of the Curve: Electric Drive Tractor Coming to U.S. & Canada | 218-4-7 | Farm Equipment Publication

John Deere's electric tractor in action - YouTube
A big JD electric tractor at the end.

The Electric Kubota BX235 - YouTube
The Electric Kubota BX2350

Solar Electric Tractor Model 12 - Steve Heckeroth - YouTube
Solar Electric Tractor Model 12 - Steve Heckeroth

4570Man · Jul 17, 2018

I don’t recall seeing very many power plugs in the field. Seeing that Kubota hurts a little. Couldn’t they have at least used a blown up unit? Maybe that motor went back to good use.

Gale Hawkins · Jul 17, 2018

4570Man said:
I don’t recall seeing very many power plugs in the field.

Why would you expect to see them in the field? These tractors take their power to the field with them. The diesel electric tractor makes a lot of sense as you may have read. The flexibility of electric powered farm tools will offer a lot of flexibility.

vvanders · Jul 17, 2018

Honestly I've wondered why we haven't seen any diesel-electric tractors. You'd have much better speed control compared to an HST without the loss of power to the PTO vs geared tractor. If you had a smaller reserve battery you could run it quiet for puttering around and kick in the diesel gen for when you needed the power.

Most electric motors are teeny so it's not like it would take a ton of extra space.

MossRoad · Jul 17, 2018

vvanders said:
Honestly I've wondered why we haven't seen any diesel-electric tractors. You'd have much better speed control compared to an HST without the loss of power to the PTO vs geared tractor. If you had a smaller reserve battery you could run it quiet for puttering around and kick in the diesel gen for when you needed the power.

Most electric motors are teeny so it's not like it would take a ton of extra space.

Probably because they are overly-complicated and the cost increase would be increadible. Also have to ask about the efficiency. Trains are efficient when they run at constant speed. Most people on TBN don't run at constant speed with their homeowner machines. Very few of us are high acreage dirt farmers that plow long furrows all day long.

vvanders · Jul 17, 2018

I totally buy the complicated argument but I don't know about cost or efficiency.

For one AC induction motors are pretty cheap to build, they're mostly just copper and the control ICs have been plummeting in prices. The huge cost in EVs come from the batteries which you'd be omitting from a diesel-electric. You also get to drop the transmission/hst costs(and even transfer case if you want to get fancy with a dual motor setup).

On efficiency that's actually one of the strengths of a diesel-electric, you can run the gen motor at a constant RPM that's at peak efficiency and then the Rotation->AC->DC->AC->Motor decouples the speeds. Right now AC motors are about ~92-95% efficient with the AC->DC being about 95% efficient you're probably somewhere in the ~10% loss ballpark which is still better than the 15-20% you pay for a HST.

The other thing that makes AC induction motors awesome is that they have the best possible traction of any motor(which is why trains use them). When the wheels break traction they don't overspin, they stay at ~1% of previous speed thanks to how the VFD controls the 3-phase timings.

Anyway, I've take us far off-topic, probably worth a separate thread rather than clutter up this one.

ovrszd · Jul 17, 2018

Gale Hawkins said:
Why would you expect to see them in the field? These tractors take their power to the field with them. The diesel electric tractor makes a lot of sense as you may have read. The flexibility of electric powered farm tools will offer a lot of flexibility.

I read an article regarding the big JD. The duty cycle times were horrible. But it's a start. Let's just make sure it's not subsidized by our tax money.