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Author Topic: Selling Listeroid made electricity back to the power grid?!  (Read 71968 times)

SCOTT

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Selling back to the grid Best way to do it?
« Reply #45 on: February 23, 2006, 11:43:20 PM »
Experts advise sought!



What I would like to do is setup a Listeroid and run it on WVO.  I would like to attach this to a 5kw gen head to produce electricity for my home and have the ability to sell any excess back to my utility.  I have had numerous conversations with the appropriate people at the utility, Connecticut Power and Light.  The regulations permit me to sell back up to 50kwh (50kw per hour) using any means I choose as long as it is a cogeneration set up.  This basically means I need to use the waste heat produced by the engine, i.e. using the heat from the engine or exhaust to heat domestic hot water.  If I use 100% renewable energy I can sell up to 100kwh (100kw per hour) back to the grid. 

As stated above I initially want to generate 5kw using a 10hp engine.  The problem I am having is figuring out how to connect the generator to the grid while meeting the requirements of the utility.  These include but are not limited to; overload circuitry,   anti islanding, and isolation circuitry ( in the event the grid power goes down)

I suppose I could buy a DC alternator hook it up the engine and hook the alternator up to a grid tie inverter, but that is an expensive proposition, on the order of $5k for the inverter alone.

Is there a way to buy a high quality AC Gen head and connect it to the grid using the appropriate panel with all the protection they require?  How would I keep the gen head producing the full 5kw without actually calling for that load?  As I understand it the generator head only outputs electricity when called upon to do so.

I have read that it is possible run an induction motor at a higher than nameplate speed and produce power that way.  To me this sounds like it is a less than optimal way of generating electricity, and I worry that my utility would not approve an “improvised” generator that would hook up to their grid. I have a feeling that something along these lines made my a manufacturer is the way to go, something that is certified to deliver stated output within specified parameters.  If anyone knows where I can get something like this please let me know.

At this point I have a good grasp on the regulatory issues and the mechanical issues are under control.  I am definitely deficient when it comes to working out the details on the electrical side of the whole process.  If there is someone out there that has a working system like what I am trying to design, please let me know how you did this in as much detail as possible.  I would also be willing to pay an electrical contractor to help design the system.  I want to set this up in the right way from the start.

All comments, ideas, corrections and the like are greatly appreciated

Scott


net metering with a 6/1 in Connecticut
12/1
6/1

DirtbikePilot

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #46 on: February 24, 2006, 12:09:43 AM »
It still isn't cheap, but here's one for 3000. http://www.rockymountainpowersource.com/Inverter-Chargers.html
Currently no listeroids, sad........ very sad.....
Just some other antique engines ranging from 40 pounds to 33,000 pounds each.

Andre Blanchard

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #47 on: February 24, 2006, 12:31:44 AM »
"I have read that it is possible run an induction motor at a higher than nameplate speed and produce power that way.  To me this sounds like it is a less than optimal way of generating electricity, and I worry that my utility would not approve an “improvised” generator that would hook up to their grid. I have a feeling that something along these lines made my a manufacturer is the way to go, something that is certified to deliver stated output within specified parameters.  If anyone knows where I can get something like this please let me know."

That should be higher then syncroness speed, 60Hz would be 3600, 1800, etc. 50Hz 3000, 1500, etc.
It really works very well just like in order for an induction motor to produce any torque it has to electrically slip run slower then syncroness speed, more slip more current more torque.  It works the same if the "slip" is in the other direction, motor being turned faster then syncroness, more positive slip the more torque it takes to turn the more current it pushes back to the grid.  If the grid goes down the generator stops generating.  Many larger windgenerators are induction generators.
You can make an induction motor generator without the grid but you have to put capacitors on the motor.
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WWIProps

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #48 on: February 24, 2006, 01:19:27 AM »
Scott,

I got the idea FROM my utility.  If you go any other route the controls cost becomes prohibitive. 

If your utility service is single phase get a single phase 7.5 HP motor for a Lister 6/1.

It works remarkably well, 500+ hours and running.

Regards,
Scott

SCOTT

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #49 on: February 24, 2006, 03:37:38 AM »
WWIProps

Was your motor an off the shelf item?  My utility indicated that they were quick to approve anything that was UL approved (or whatever the equivilant utility designation is) or came from a "respected" manufacturer.  Mainly the commercial grid tie inverters that are available.  (DC to AC) I would like to learn more about how you got your setup approved, what they ask, look at etc.  If you still have the contact info for the person you spoke to at the utility that may be helpful. I too am single phase with 100 amp service so it looks like we have a similar initial service.  Did you purchase a motor and hook it up to the lister and run above synch speed while connecting the motor to your service panel?  I will re-read the topic again tomorrow to see if there is anything I missed. 
Thx for the reply 
Scott
net metering with a 6/1 in Connecticut
12/1
6/1

DirtbikePilot

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #50 on: February 24, 2006, 05:22:55 AM »
I was under the impression that an induction motor never "slips" or goes below its exact rated rpm unless it is overloaded. Wouldn't it just be pushed by the sine wave essentially? The more load, the more the magnetic field from the rotor would lag behind the field produced by the stator coils? I've never been taught this, but it just seems to make more sense that way. By this reasoning, the rated rpm would also be exactly what rpm it is running at regardless of weather it is being a generator or a motor. The only difference would be that in the case of the motor acting as a generator the magnetic field form the rotor would be "pushing" the field made by the stator coils instead of being pulled by them. I would think that any time that if the rotor was out of sync with the stator for very long, the motor would have excessively high current draw and burn up. Does anyone here know if that is in fact how this works?
Currently no listeroids, sad........ very sad.....
Just some other antique engines ranging from 40 pounds to 33,000 pounds each.

DirtbikePilot

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #51 on: February 24, 2006, 05:44:00 AM »
Now I've got another question for wwiprops. Exactly what motor are you using? I've never seen a 120v motor in that horsepower range. The ones I've been able to find are at least 230 volt motors. I suppose that you could hook it up to the 220 utility, but I don't see how this would work because there would be no neutral. [monty python]"How does it um..... how does it work?"[/monty python]
Currently no listeroids, sad........ very sad.....
Just some other antique engines ranging from 40 pounds to 33,000 pounds each.

WWIProps

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #52 on: February 24, 2006, 11:25:55 AM »
I have been using a WEG 5HP but am graduating up to a Baldor 7.5 ODP Single Phase 230 Volt off the shelf motor.  I have to remove the capacitors and only use the run circuit of the motor for my generator.  The capacitors are removed to ensure that there is no chance of me powering the lines when the grid is down.  As an added safety feature I had to purchase a magnetic starter to.  If grid power goes away the starter drops the generator off line as well. 

I won't go into the theory of operation, there are people far more qualified than I am to discuss that.  In actual operation I run the motor/genrator 1820-1830 rpm.  I have found that I  can run the generator at up to 30 amps without the lister smoking.  The 5HP motor would over heat if ran that way for too long hence the reason for the 7.5Hp motor.  Now, that is not really 30 amps of power, a significant portion of that (about 14 amps) is for excitation.  Those amps come in the form of VARs that are not read by my utility meter.  When I have shut off all of the loads in the house I have been able to send 3.7 kW back into the grid as read at the utility meter.

As far as the neutral is concerned you are right, there is none from the gnerator but apparently the tap off of the utility transformer outside of your service entrance takes care of that.

Regarding slip and going below the rated rpm...if I turn off the fuel on the lister the genrator goes back to being a motor and drives the lister drawing power from the grid.  So, one control item you might consider is a reverse power relay that disconnects the gnerator in the event the lister runs out of fuel etc.

The nice part about this is it can be very cheap if you find used equipment and it sticks with the KISS principle.  Just look at controls for a self exciting gnerator and the frequency requirements etc.  I am not sure you can meet the utility requirments with a lister without overcoming the governor and power stroke variations.

Good luck.

Scott

Andre Blanchard

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #53 on: February 24, 2006, 02:49:44 PM »
"I was under the impression that an induction motor never "slips" or goes below its exact rated rpm unless it is overloaded."

For the most part that is true but the rated (nameplate) speed is less then the synchronous speed.  The field in an induction motor is created by transformer type action between the stator and the rotor.  If the rotor is spinning at the same speed as the magnetic field created by the stator then there is no relative motion between the conductors in the rotor and the magnetic field so on induced current in the rotor so there is no magnetic field is created by the rotor.  As the speed difference gets larger the induced currents in the rotor get larger so its magnetic field reacts with the stators magnetic field more strongly.
  The magnetic field created by the currents in the rotor is spinning at the same speed as the stator field but the physical rotor is not.
When you overload the motor the induced current in the rotor gets so large that the iron in the rotor and the stator and not handle the magnetic fields and is saturated.  At that point the motor is basically a transformer with the secondary winding shorted.


WWIProps, I have wondered if a setup like yours could be governed by something like this.  Take an AC solenoid like the kind on old washing machine transmissions, replace the coil with one wound with just a few turns of a much larger wire say #10 and connect this in series with the generator.  Then connect the armature of the solenoid to the governor on the engine such that as the current from the generator goes up the solenoid pulls in harder slowing the engine down.

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DirtbikePilot

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #54 on: February 25, 2006, 01:04:43 AM »
Oh...... Cool. That makes sense. Thanks for explaining that.
Currently no listeroids, sad........ very sad.....
Just some other antique engines ranging from 40 pounds to 33,000 pounds each.

WWIProps

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #55 on: February 26, 2006, 05:47:31 PM »
"WWIProps, I have wondered if a setup like yours could be governed by something like this.  Take an AC solenoid like the kind on old washing machine transmissions, replace the coil with one wound with just a few turns of a much larger wire say #10 and connect this in series with the generator.  Then connect the armature of the solenoid to the governor on the engine such that as the current from the generator goes up the solenoid pulls in harder slowing the engine down."

Andre, you got me on this one.  I don't know.

Scott

mikey

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #56 on: February 28, 2006, 07:35:12 AM »
I have a 20 hp 3 phase induction motor. Can I generate single phase power for net metering with this motor?

trigzy

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #57 on: February 28, 2006, 07:28:29 PM »
Mikey,
        It depends what voltage the motor is.  The technical answer is yes, but there are A LOT of considerations to cover.  Once of the main ones being imbalance.    Would be MUCH MUCH simpler with a 1 phase motor, maybe you could trade someone.....

Steve
Power Anand 24/2, Brushless 20kW, some other antique iron.
Vendor of AVR's, Small Clones of Yanmar Diesel and Honda Gasoline Engines

Doug

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #58 on: March 01, 2006, 02:25:25 AM »
Echo.... 
It will work its only good for about 10 HP on single phase and it won't be quite as efficient as a large single phase.

Provided its a 208 motor.
Might even be nice it make an add a phase with too. You never know when a little three phase around the home/shop could be handy.

pigseye

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Re: Selling Listeroid made electricity back to the power grid?!
« Reply #59 on: April 09, 2006, 06:01:08 AM »
This is a great topic and I wanted to bounce it back up and ask a few questions.

Whenever I talk to someone about a lister based generator they all say, "You need to net meter."  I live in WI so net metering up to 20KW is acceptable.

But the cost and technical side of net metering can be challenging to say the least. 

Here are my questions:

I'm trying to find high HP single phase motors.  Any suggestions on where to look?  I live near the twin Cities in MN.

Can I safely spin two motors on one lister to increase the current capacity of my system? 

Is it cheaper or easier to purchase 2 10 hp single phase motors than one 20 hp motor?

Let's presume I'm running my 220V single phase net metered generator that can supply 30 amps across 220V.
What happens if I my usage goes to 40 amps?   Does the generator provide up to 30 amps and then the grid provide 10 amps?   
What happens if I'm only drawing 20 amps?  Is the generator pushing 10 amps back into the grid?
Is it really that simple?

Now let's assume the grid goes down and my generator automatically turns off.  I go to the main breaker and turn it off it so the generator doesn't push power onto the lines.  I fire up my generator to regain power to the house. 
What happens when the grid power is back up? 
How do I resync? 
Do I just flip the main breaker back on or do I need to shut down the generator, flip the breaker back on, then start the generator again to resync it with the grid

Is there anyone on this forum who is successfully net metering in WI?

Finally, WI biomass limitations includes the use of up to 25% fossil fuel for biomass systems.  So it looks like running a lister on WVO or biodiesel meets WI net metering requirements.

TERMS AND CONDITIONS
1. Renewable resource generators are generating systems which exclusively utilize solar, wind, geothermal, biomass, including
waste-to-energy and landfill gas, or hydroelectric. Biomass systems are allowed to blend up to 25% fossil-fuel as needed to ensure safe, environmentally sound operation of the renewable energy system. A customer using biomass blended with fossil-fuel as their renewable energy source must submit proof to the Company substantiating the percentage of the fossil fuel blend either by (1) separately metering the fossil fuel, or (2) providing other documentation that will allow the Company to correctly apply a generation credit to the output associated with the customer’s renewable fuel only.

Thanks,
Pigseye
« Last Edit: April 09, 2006, 06:20:01 AM by pigseye »