PTO generator

[yelbike]

Just a suggestion to figure out your loading/ sizing. Pick up an amprobe or clamp on amp meter. Princess auto has them cheap like $20, i would assume hf would have them also. Remove you panel cover and install the meter on your service conductors. One conductor only not both at same time. Now turn off non essential loads and lights throughout the house. Prop the fridge door open, same with the freezer, turn on any other loads that will run like the blower for a gas furnace. You get the point. Take a reading on each conductor. Take the highest reading and multiply by 240 to give the watts. Now you have the actual minimum amps required for you situation. Add some safety margin, say 30%. Good to go. Don't go stupid larger if you don't need it.

 

[Rob-D]

What's a PV?

Photo Voltaic (Solar Panels)

 

[Rob-D]

Good question I would be interested if there is.

OK, some clarification. An inverter changes AC to DC or visa versa. Solar panels convert the sun's energy to DC (direct current) voltage. The DC is anywhere from 12 volts to several hundered volts depending on the PV string length. (how many panels are connected in series). The inverter changes the DC to AC (alternating current) which is what houses run on, usually 240/120 AC.

We could make an inverter system by generating DC run from a PTO but there are several problems with this. Generating DC is what we used to do in cars 60 years or more ago. It requires a DC generator and DC generators require commutators and brushes. Today we use three phase alternators in cars that only require slip rings or no rings in gensets. The three phase is rectified using diodes to give us DC to charge our car batteries. A genset only needs an alternator (AC) in doesn't need to change the energy to DC, all it has to do is give us our 120 or 240 AC to run our houses. No brushes and no conversion to DC. To get the 120 AC all we have to do is make sure our alternator runs at a specific rpms. It's the rpms that vary the 60 Hz frequency that US houses run on.
To make a DC inverter system adds a lot of complexity to power generation, that's why it's rarely done.

 

[GPintheMitten]

Thanks, Rob.

Photo Voltaic (Solar Panels)

 

[Rob-D]

Thanks, Rob.

Glad to help.

 

[Charlesaf3]

I've figured that if I had to use the pto generator to power my house in the city I'd back feed the garage (I wired up to do it legally). Park tractor in there, no issues except for exhaust, and yeah I am concerned about that - in city so leaving door open isn't ideal. I've been wondering if there was some way to pipe the exhaust outside - some sort of high heat flexible pipe?

My kubota is incredibly reliable. And burns almost no diesel. My experience with cheap gas engines has been pretty bad, I just can't see relying on anything but a Honda to power in an emergency. Diesel generator would be great, but it was noticeably more expensive than pto.

I ran a gas generator borrowed from my electrician for a week during Irene. It was insanely loud, and needed constant gas. Fine for a job site, but not really a long term solution

I actually bought a 20amp xantrex pure sign for my truck. For a lot of things on job sites, I can actually see that being all I need

 

[Rob-D]

I've figured that if I had to use the pto generator to power my house in the city I'd back feed the garage (I wired up to do it legally). Park tractor in there, no issues except for exhaust, and yeah I am concerned about that - in city so leaving door open isn't ideal. I've been wondering if there was some way to pipe the exhaust outside - some sort of high heat flexible pipe?

My kubota is incredibly reliable. And burns almost no diesel. My experience with cheap gas engines has been pretty bad, I just can't see relying on anything but a Honda to power in an emergency. Diesel generator would be great, but it was noticeably more expensive than pto.

I ran a gas generator borrowed from my electrician for a week during Irene. It was insanely loud, and needed constant gas. Fine for a job site, but not really a long term solution

I actually bought a 20amp xantrex pure sign for my truck. For a lot of things on job sites, I can actually see that being all I need

The trouble with that is the Xantrex for the truck is 12v. So let's say your house uses 2Kwh, that means 2k/12 = 166 amps draw from your battery and alternator. That's ok for small stuff like running a sander or lights on a job but your house most likely uses more than the 2Kwh I conservatively used in this example. For instance my off grid system is 48 to 72 volts nominal. (24v panels) Two 24v panels will run anywhere from 60 to 80 volts into the inverter, my other panels are a srting of 3 for 72 volts nominal or about 105 volts when the sun is running them. The higher the voltage the less copper wire for your runs. That's what you want, now back to the 48 volt battery bank that these panels charge. With the 2Kwh we used above: 2000/48 = 41 amps worth of copper. So to run an inverter from a battery bank you want at least 36 to 48 volts. So how do you charge that from your vehicle? Well, you'll need a special alternator and charging system. That's why your inverter system isn't the best. After you start putting appliances, etc. on the load end you won't be able to maintain them.

 

[aczlan]

Couple pieces of exhaust pipe connected to the exhaust pipe of your tractor with a silicone hose should do the trick. Make sure to setup a remote kill switch outside the garage and a couple of CO2 meters in the garage...

Aaron Z

 

[zoltanthegypsy]

OK, some clarification. An inverter changes AC to DC or visa versa. Solar panels convert the sun's energy to DC (direct current) voltage. The DC is anywhere from 12 volts to several hundered volts depending on the PV string length. (how many panels are connected in series). The inverter changes the DC to AC (alternating current) which is what houses run on, usually 240/120 AC.

We could make an inverter system by generating DC run from a PTO but there are several problems with this. Generating DC is what we used to do in cars 60 years or more ago. It requires a DC generator and DC generators require commutators and brushes. Today we use three phase alternators in cars that only require slip rings or no rings in gensets. The three phase is rectified using diodes to give us DC to charge our car batteries. A genset only needs an alternator (AC) in doesn't need to change the energy to DC, all it has to do is give us our 120 or 240 AC to run our houses. No brushes and no conversion to DC. To get the 120 AC all we have to do is make sure our alternator runs at a specific rpms. It's the rpms that vary the 60 Hz frequency that US houses run on.
To make a DC inverter system adds a lot of complexity to power generation, that's why it's rarely done.

True that, but there are some very nice inverter generators out there. The neighbor has a Honda 6000 that's very quiet. The engine doesn't have to run at a fixed speed to maintain a 60Hz line frequency, and only revs when load demands. The inverter takes care of the AC side.

There are also some significant advantages in terms of noise and efficiency.

This is why I asked about an inverter PTO generator. The tractor wouldn't have to run at an exact (high) RPM to maintain the output at 60Hz, and could _maybe_ run slower and quieter. Just speculation on my part, since I haven't seen such a beast.

This is probably OT for this discussion, though...

Z.

 

[aczlan]

This is why I asked about an inverter PTO generator. The tractor wouldn't have to run at an exact (high) RPM to maintain the output at 60Hz, and could _maybe_ run slower and quieter. Just speculation on my part, since I haven't seen such a beast.

A simpler way to do it would be to use a tractor with a 1000RPM PTO throttled back so that the PTO was spinning at 540RPMs. John Deere does this with their 'ePTO' and many older tractors (such as our B7500) have a 1000RPM rear PTO setting.

Aaron Z