Generator PTO vs Gas Engine Generator

[WVBartMan]

The snow (10") was wet and heavy and took down some trees but no power loss, we got lucky, those around us lost it for several days.

 

[dex3361]

The snow (10") was wet and heavy and took down some trees but no power loss, we got lucky, those around us lost it for several days.

I spent a few days in Webster County where the snow was over 36" of the heaviest wettest snow I have ever seen. We got about 8 or 9 inches where I live and I didnt loose power at home either. Snow started early this year.

 

[davel8257]

Back to the PTO twisting ... we've been really lucky by not having any extended power losses here in Southern IN. But North or South of us has been a different story. The more regular use that I would have for PTO generator is to pull a farm wagon decorated for a parade. We have a calliope that is driven by 1HP (110v) electric motor. At Christmas time, we pile on the lights. We have 3 other events during the year. I was thinking of bolting some kind of a bracket to a draw bar. Mount the generator to one side, pull the wagon from the other side. A concern that I have is maintaining RPM (& therefore 60hz). Picking a gear to drive in the parade will be a challenge -- need to match speed with the unit in front of you or risk wearing out the clutch.

 

[WVBartMan]

Davel8257 - I've seen to many funny movies concerning Christmas so please forgive me if I sound a little off, no disrespect intended. Using a gear driven tractor to keep the PTO at 540 in traffic in order for the generator to properly work, with possible riders on the trailer, tractor screaming loud, lights going on and off due to slowing down and speeding up, upset riders, eggnog chunky possibly spoiled but vodka hiding the sourness, I see this as something I want to be a part of with my video camera. I would suggest getting a small generator to mount in the FEL to keep sound/exhaust fumes to a minimum for the riders or a hydrostatic driven tractor.

I'm charging the battery in the camera so I'm prepared either way.

 

[davel8257]

WQVBartMan - Exactly my thoughts as well. I really debated the hydrostatic drive option before I bought my Kioti - but I went with gear drive for all of the other uses. I've got some heavy pads that I could line the FEL -- that might be the best option.

 

[jgayman]

Even a Hydro tractor would need to be screaming the engine to maintain proper PTO speed. I recommend buying/borrowing/renting one of those small super-quiet suitcase-sized 2KW Honda generators. With the tractor engine idling I doubt anyone would even hear it running.

 

[Mickey_Fx]

Funny how when the season turns to winter how the conversation turns to generators.

Getting back to the original question, the proper answer is it depends. Each of us have different needs and when a tractor comes into the decision, its characteristic also has to be considered. Things to consider for going with a PTO setup is, what's the likelihood of needing the tractor for other things and if that's the case, how frequent. The other thing when considering a PTO setup is, how good of a job does YOUR tractor do in maintaining speed as loads change. Some thing aren't sensitive to freq drifts and other things are pretty sensitive. The things that are sensitive are things with induction motors (motor that don't have brushes). Induction motors are likely going to protest being run say 10Hz off the rated freq needs. Equipment that could be affected are things like your refrigeration appliances, blowers/fans (think heating systems), compressors, well and sump pump and similar things.

As for a stand alone generator, fuel is a consideration. I'd rule out propane unless you already have a LARGE tank and temps don't get too cold if power outages during the winter months are a possibility. For gasoline, I've not ever had a problem with gas. As a matter of fact, I've been remiss in running the engines in our motorhome. MH hasn't been out of the shop for maybe 18mos and gas is older than that. This week when I tried to start the engines, both, chassis and generator, started within a couple sec and both were run for about 30 min. Have a number of other engines that are used infrequently and fuel has never been an issue. If you're concerned about leaving fuel in the tank, drain it. As to availability, if one has a few days notice of a pending storm, stock up beforehand. Oh, I do treat winter fuel with Sta-Bil. If natural gas is available and generator is fixed mounted, this might be a very good choice.

One issue I have is I don't understand the need of some saying they'd run their genny 24/7. This especially doesn't make sense if fuel availability is an issue. I've not had the need so far but if the time comes, I'll be using 2 generators. A small 1kW inverter that will see service most of the time and a larger one to be used a couple times a day for short periods to replenish the well water and cool down the refrig equipment. What we've always done during outages, we've always had advance notice, is to fill the bathtubs for water supply to flush the stools and wash hands. Will have a few gals of drinking water that will hold us over for a day or two if needed. Except for the heavy loads, we can get by on 500W of power. That will run the pellet stove, TV and all that is connected to it and keep the internet and computer running plus lights in several rooms. The little genny uses about 3 qts of gas over ~5 hrs of operation @ half load. The bigger one uses ~1 gal hr but it won't be used much more than an hr or two at most day. Don't need large qtys of gas to be on hand. Longest time we've every went without util power is 3-4 days and that was yrs ago. Here at the new place the longest we've been without power is maybe a day and a half.

 

[TerryR]

I'd rule out propane unless you already have a LARGE tank and temps don't get too cold if power outages during the winter months are a possibility.

Mickey,

Why do you see a concern about cold weather and propane?

Terry

 

[joshuabardwell]

Mickey,

Why do you see a concern about cold weather and propane?

Terry

In cold weather, the vapor pressure of the propane decreases. This means that, effectively, the tank runs out faster. There will still be liquid propane in the tank, but it will just be sitting there, not vaporizing, and so the lines won't be pressurized. What this means is that if you intend to have 200 gallons of propane to run a generator with, you may need a 400 gallon tank to provide enough vapor pressure to keep the propane flowing.

 

[hobtink]

Butane is more subject to the lower or pressure problem with lowering of temperature, that and leaking Butane was bad about holding in low points during a leak and it has not been used for home use even in the South for 2-3 decades or so for home heating, from what I understand the largest use of Butane now is to raise the octane level of gas to make premium blends and it will supposedly offgas from a tank left in the hot sun after a few days to weeks leaving you with high priced regular octane grade gas. Propane is suppose to maintain the same relative availability as long as there is some liquid in the tank because it boils of to a gas as it is released into you line from the tank, that is not to say that temperature cannot affect pressure, but you are talking about a very modest inches of WC to a few psig, many tanks are below ground. I am in and from the South so I have not experienced su-zero temps. So the only problem I see with any of these fuel and power sources for your generator are several fold; how, where,who and the knowledge to safely connect temp power an return to utility power, putting extra hours on your tractor may affect resale value but a diesel was made to be ran if you don't need or want to maintain another internal combustion engine use your tractor. Need for use of tractor to do other things more than run a gen set but more so keeping tractor RPM setting so that PTO output is within 60 cycles, and the cost per unit of energy generated from fuel consumed and fuel availability versus storage and replenishment. Per unit, NG has less energy than propane to memory and both are costly during the winter as is home heating oil(basically #2 diesel). However, even air cooled engines without oil filtration powered by propane or NG will run clean and long and you don't have to worry about water or soured fuel, varnish separating from gas or paraffin or algae from diesel causing shutdown or loss of power, especially if you do not use something like Lucas fuel stabilizer and run the fuel through the engine to distribute the fuel stabilizer instead of just adding it to the tank, it needs to get into the entire fuel system especially the carburetor / injectors. Diesel can grow algae, and can thicken, Powers diesel additive / lucas fuel stabilizer will also help here. Depending on grade of diesel purchased thickening from paraffin related fuel problems requires more watchful observation of your fuel supply in your generator/diesel tractor and your backup fuel source resulting in a chance of the tractor/generator not starting or running long and the overall cost to operate and value. Also some diesels have areal hard time starring in cold weather. There are several things to consider. Adding a stand alone generator of adequate continuous load wattage, self start, auto transfer loading and un-loading, that runs monthly self tests and is connected to a dedicated and reliable source of propane(large tank) or natural gas generator however expensive if you can afford it will add physical and emotional comfort and security should even prevent frozen pipes in winter and lost refrigerated / frozen groceries in summer not to mention giving cooling AC comfort in the summer. Make a pro's and cons for your use and area and conditions.

 

[hobtink]

Butane is more subject to the lower or pressure problem with lowering of temperature, that and leaking Butane was bad about holding in low points during a leak and it has not been used for home use even in the South for 2-3 decades or so for home heating, from what I understand the largest use of Butane now is to raise the octane level of gas to make premium blends and it will supposedly offgas from a tank left in the hot sun after a few days to weeks leaving you with high priced regular octane grade gas. Propane is suppose to maintain the same relative availability as long as there is some liquid in the tank because it boils of to a gas as it is released into you line from the tank, that is not to say that temperature cannot affect pressure, but you are talking about a very modest inches of WC to a few psig, many tanks are below ground. I am in and from the South so I have not experienced su-zero temps. So the only problem I see with any of these fuel and power sources for your generator are several fold; how, where,who and the knowledge to safely connect temp power an return to utility power, putting extra hours on your tractor may affect resale value but a diesel was made to be ran if you don't need or want to maintain another internal combustion engine use your tractor. Need for use of tractor to do other things more than run a gen set but more so keeping tractor RPM setting so that PTO output is within 60 cycles, and the cost per unit of energy generated from fuel consumed and fuel availability versus storage and replenishment. Per unit, NG has less energy than propane to memory and both are costly during the winter as is home heating oil(basically #2 diesel). However, even air cooled engines without oil filtration powered by propane or NG will run clean and long and you don't have to worry about water or soured fuel, varnish separating from gas or paraffin or algae from diesel causing shutdown or loss of power, especially if you do not use something like Lucas fuel stabilizer and run the fuel through the engine to distribute the fuel stabilizer instead of just adding it to the tank, it needs to get into the entire fuel system especially the carburetor / injectors. Diesel can grow algae, and can thicken, Powers diesel additive / lucas fuel stabilizer will also help here. Depending on grade of diesel purchased thickening from paraffin related fuel problems requires more watchful observation of your fuel supply in your generator/diesel tractor and your backup fuel source resulting in a chance of the tractor/generator not starting or running long and the overall cost to operate and value. Also some diesels have areal hard time starring in cold weather. There are several things to consider. Adding a stand alone generator of adequate continuous load wattage, self start, auto transfer loading and un-loading, that runs monthly self tests and is connected to a dedicated and reliable source of propane(large tank) or natural gas generator however expensive if you can afford it will add physical and emotional comfort and security should even prevent frozen pipes in winter and lost refrigerated / frozen groceries in summer not to mention giving cooling AC comfort in the summer. Make a pro's and cons for your use and area and conditions.

 

[TerryR]

In cold weather, the vapor pressure of the propane decreases. This means that, effectively, the tank runs out faster. There will still be liquid propane in the tank, but it will just be sitting there, not vaporizing, and so the lines won't be pressurized. What this means is that if you intend to have 200 gallons of propane to run a generator with, you may need a 400 gallon tank to provide enough vapor pressure to keep the propane flowing.

Thanks, Joshua,

Doesn't the same issue apply to all other uses of the propane? If it were a real issue, how could I use it to heat my home, run the boiler, dryer, range, etc.? I've never seen any issue even after days of near-zero temps.

In any case, I thought large tanks of a size that can reliably supply a generator for an extended period are buried and thus experience limited temperature swing.

Terry

 

[aczlan]

Doesn't the same issue apply to all other uses of the propane? If it were a real issue, how could I use it to heat my home, run the boiler, dryer, range, etc.? I've never seen any issue even after days of near-zero temps.

Yes it does, the difference is that a genset will be pulling at least as much propane as your boiler, dryer and range combined.

Aaron Z

 

[TerryR]

Yes it does, the difference is that a genset will be pulling at least as much propane as your boiler, dryer and range combined.

Thanks, Aaron -

Makes sense - the genset runs on a "high pressure" (10 in. of water?) line, while everything else in the house runs behind a regulator that reduces the pressure (to 1/2 in. of water?). I was told when it was installed that they would have to run a much larger pipe to the genset at lower pressure. At the higher pressure it's a 1/4" copper line.

So, at what outside temps does this really matter? Especially with a buried tank? With a genset sized to start the well pump, freezer, and fridge at the same time, it runs at very light load most of the time. And as someone pointed out earlier, you don't run it 24/7, in our case because of the noise if nothing else. A 1000 gal tank should last a long time, I'd think, even if cold.

Terry

 

[Mickey_Fx]

Mickey,

Why do you see a concern about cold weather and propane?

Terry

Josh pretty much cover the issue but I'll add a couple things. Propane's ability to vaporize is tied to the tanks temp. As you get down to freezing temps vaporization is very slow. Over on Yamaha's web site the do go into the of the details and has charts showing how large a tank is needed at various temps for various sized generators. For a 7kW generator @ 20F, a tank of 400-450 gals is needed to keep up with demand. Surface area of the liquid propane plays a part as well. The tank recommendation was for horiz tanks as they offer the greatest surface area. For max vaporization the tank needs to be half full. Liquid level either higher or lower reduces the surface area and the amount of vaporization taking place.

This problem can be addressed if the tank has a wet leg, thus pulling liquid propane from the tank. The liquid then is moved to a warmer area where is it vaporized and can more easily keep up with the demand. I'm not a propane expert so I don't have any idea how small of a tank can be had with a wet leg.

Don't use propane here and can't justify a large tank for the generator that might be called on one every couple yrs. My larger genny I bought used, Only had about an hr on it. It was rigged for propane. First thing I did was remove the propane setup. Gas tank had never had any fuel in it.

 

[Mickey_Fx]

Thanks, Aaron -

Makes sense - the genset runs on a "high pressure" (10 in. of water?) line, while everything else in the house runs behind a regulator that reduces the pressure (to 1/2 in. of water?). I was told when it was installed that they would have to run a much larger pipe to the genset at lower pressure. At the higher pressure it's a 1/4" copper line.

So, at what outside temps does this really matter? Especially with a buried tank? With a genset sized to start the well pump, freezer, and fridge at the same time, it runs at very light load most of the time. And as someone pointed out earlier, you don't run it 24/7, in our case because of the noise if nothing else. A 1000 gal tank should last a long time, I'd think, even if cold.

Terry

Are you sure about your pressure settings? In an RV the pressure setting is 11-12" water column. Pressure at 12" water column is ~.47 PSI. That's the pressure all the gas appliances run on in RV's.

If you propane tank is buried, the temp variation isn't anywhere near as severe as an above ground tank. Nothing to be concerned about unless you live up N where the ground can freeze several ft deep.

 

[TerryR]

Are you sure about your pressure settings?

Not at all. I was trying to recall what the installers told me 15 years ago, and obviously got them wrong. The low pressure seems to be 10 or 12" of water, so the high pressure line is obviously more, but I don't recall a number for that. That's the pressure on the line from the tank to the regulator that supplies the appliances in the house, and it also goes to the outlet for the turkey fryer and to the genset.

If you propane tank is buried, the temp variation isn't anywhere near as severe as an above ground tank. Nothing to be concerned about unless you live up N where the ground can freeze several ft deep.

The top of the tank is at least a foot deep, and local codes say the freeze depth here is two feet, which is no doubt conservative. The propane dealer put in a 1000 gal. tank, which holds about 2/3 of our annual usage, because he didn't want to try to get trucks up or driveway in the middle of the winter. It's mounted horizontally, so between the large size and the sheltering effect of being well buried, the recommendations you mention suggest we have considerable margin.

Terry

 

[Copperhead]

I had a generac portable unit that did ok. But just picked up a John Deere PTO generator the other day I ordered a couple of weeks ago. 10kw rating mounted on a a nice 3pt platform. Real solid unit. Should work great for standby power and a great unit for getting power somewhere on my property where I need it. The dealer hadn't stocked or had a demand for any of these. When mine showed up, he had it on the main floor of the dealership a few days before I picked it up. He got a few orders for them once others saw the unit.

 

[kateean2]

I'm thinking about the same thing, but also am factoring in that I might want to be off the grid someday.

 

[msch2112]

hi,

i'm thinking of a 25kw PTO generator for my 105hp JD. it wouldn't be used often but there more for long term issues down the road if need be. i don't want to tap into our propane tank because i want that fuel available elsewhere and i'ld probably burn 2 gallons of propane/hr. just how many gallons of diesel per hour would my tractor burn at 540rpm? i've got the 4 cylinder diesel engine.

thanks,

mike