Generator PTO vs Gas Engine Generator

[Soundguy]

Did you read the PDF I linked? It has a table with x PTO HP used = y gallons of fuel used per hour.
Of course you will use less fuel running a tedder than you would running a bush hog, but that tractor will use ~1.7 gallons of fuel per hour just to spin the engine at 2200 RPM.

No.. obviously he didn't.. or didn't understand what he read.

load determines fuel usage...

[daybreak1998]

No.. obviously he didn't.. or didn't understand what he read.

load determines fuel usage...

Howdy,
The problem is I did read it.
The answer is I have real world results, but with a different tractor. I saw the JD 5105m listed as his tractor. He said he has a 105hp tractor. To me that is then really into the 6000 series tractor. But with all the naming changes with deere tractors, I dunno.

True.. a 25kw pto generator running off a 48hp tractor totally loaded amp load to 25kw prime. Yes, it will swallow some diesel. Tractor data shows his 5105m can have the 540e mode. I am not sure if he ordered that. (yes, lots of folks flip the shaft and run 1000 pto speed then with a converter (21-spline to 6-spline))

[Soundguy]

no matter HOW you do it. load determins fuel usage.. period...

[Mark Petrowicz]

Mike,
fuel consumption would be the same if you were running the tractor at 2500 rpm with or with out the generator i imagine as you will need th pto up to a certian speed to generate the power. to generator 25kw u will need a very large coiled motor . what were you lookin at for voltage and amperage? you might want to generate 3 phase power say 480v and step it down with a transformer if you need a lot of power. always consult an electrical engineer before you go into anything like this prior to putting down any green backs.
Good luck
Mark

[davel8257]

A theoretical approach based upon the energy content of diesel fuel is interesting. Here's a link to a website that converts Kwh to gallons of diesel fuel: Convert kWh to gallon [U.S.] of diesel oil - Conversion of Measurement Units

If you plug in 10Khw, it comes up with .245 gallons (per hour). That's the theoretical maximum, no friction, no losses, 100% efficiency. If our cars could do that, we'd all be getting more than 100 MPG.

[aczlan]

Mike,
fuel consumption would be the same if you were running the tractor at 2500 rpm with or with out the generator i imagine as you will need th pto up to a certian speed to generate the power.

Not so. Take a look at page 3 of my link earlier.
From that page:
HP - RPM - Gal/hr
91.76 - 2100 - 5.71
68.65 - 2106 - 4.51
45.54 - 2093 - 3.35
22.88 - 2103 - 2.21
0.59 - 2107 - 1.15

So, 91HP used at 2100 engine RPM burned 5.71 gallons per hour while 22.8 HP used at 2103 engine RPM burned 2.21 gallons per hour and 0.59 HP used at 2107 engine RPM burned 1.15 gallons per hour.

Aaron Z

[Mark Petrowicz]

Aaron,
Thanks for the info.

[Soundguy]

Aaron,
Thanks for the info.

yep.. it's not the 'rpm' that uses the fuel.. it's the LOAD... load determins fuel. though you will get a practical 'floor' where you will have some minimum amount of fuel usage no matter what.. etc..

[msch2112]

Not so. Take a look at page 3 of my link earlier.
From that page:
HP - RPM - Gal/hr
91.76 - 2100 - 5.71
68.65 - 2106 - 4.51
45.54 - 2093 - 3.35
22.88 - 2103 - 2.21
0.59 - 2107 - 1.15

So, 91HP used at 2100 engine RPM burned 5.71 gallons per hour while 22.8 HP used at 2103 engine RPM burned 2.21 gallons per hour and 0.59 HP used at 2107 engine RPM burned 1.15 gallons per hour.

Aaron Z

i can't believe a 7rpm increase resulted in a 4.56gph reduction! guess it's the decrease in HP.

Mike

[aczlan]

i can't believe a 7rpm increase resulted in a 4.56gph reduction! guess it's the decrease in HP.

Yes, it is all about the HP used. Compare the numbers for 68.65 HP (2106 RPM, 4.51 GPH), 45.54 HP (2093 RPM, 3.35 GPH) and 22.88 HP (2103 RPM, 2.21 GPH)

Aaron Z