Selling Excess Power

robertc65

I have heard forever that it's possible to sell power to the utility company if you produce more than you can use. I'm not in a situation to do this, but if I were is this actually possible. I'm pretty savvy when it comes to things electrical or electronic, but from a physical connection standpoint I don't know how this could be done. How could you puch power back through the transformer? Is this possible or is it an urban myth.

Thanks

Rob

mickeyco

Not a myth, not only can you sell them your excess power, they HAVE to pay for it (The Public Utility Regulatory Policy Act of 1978). Years back I worked for IMC in Illinois (now Mallinckrodt, the St' Louis guys will know it) and we had 4 Generators, each the size of a semi, they would power the entire city, occasionally in the summer time, when there was high demand, the POCO would ask to us to fire them up to help, and they paid.

There's equipment that needs to be installed prior to doing it.

JamesNLA

Totally do-able.
Power back to line voltage grid is measured.....a check is cut. And yes, equipment needs to be installed - inspected.

__________________
"....And then we all switch places when I ring the bell"
-Adrock

PressurePros

Anyone know where I can buy a windmill?

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Pressure Washing PA
Roof Cleaning Services PA

jbelectric777

most installations are'nt worth it in the long run... the time to recover your investment is long. I know of a County office that did it, I inspected it, when the director told me how long it would take to get the initial cost of install back i couldnt beleive it, and they had a HUGE solor photovaic system.....

mdshunk

Consider also that they sell you power at retail, but buy it back at wholesale. The price disparity is pretty dramatic. Plus, the equipment required to sync with the utility is pretty salty.

robertc65

OK. So nobody knows how this is done. What does the equipment do? How does it work?

Rob

mdshunk

Robert, the equipment is not exotic. It just basically gets your sine wave matching the utilities sine wave, then you're basically just hooked up to the meter, pumping power backwards. Think of basically firing up your personal generator, and plugging it right into the meter. That's about all there is to it. The equipment also normally gets a radio signal from the power company so they can shut you down by "remote control" when they go to do work on the lines. Do a Google on "grid tie interface".

Do you have something particular in mind, why you're so excited about this?

mickeyco

What he said (MD) and a reversable meter (most will run in reverse, not all of them though)

Do a google search for "net metering".

mdshunk

In this day and age, the utility will normally install a special "net meter", to keep track of how much you got from them, and how much they got from you, separately. This is because the rates are different, as I explained before. Sometimes, they want you to install a completely different meter next to your regular meter for what you're selling back. They even have this two-headed adaptor thing they can put in your meter can to plug in two meters. One for what you're buying, and one for what you're selling. Every utility likes it different ways... you're working to THEIR RULE BOOK. It's their safety on the line, after all.

When you're doing a grid-tie system, you can't really buy a blessed thing until you go through the utility's engineering process. Find out what all interlocks and other equipment they want. They can, and often do, make it somewhat difficult on you. Just find out up front, and go to town...

Teetorbilt

Look here http://www.motherearthnews.com/article-categories.aspx

__________________
You can't solve you're problems with the same level of thinking that created the problems.

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Mike Finley

Ahh,, selling power to the utilties... this is a dream of mine, I think it's the ultimate stick it to the man!

747

The electric meter will actually start turning the other direction. IN the state of Illinois com ed is required under the law to buy it back. However you would be talking a serious investment. You would need a system which would handle your load plus give back to electric company. Most people just install systems to reduce there Consumption.

JamesNLA

Here.....Here's what some of the gear looks like.....



And this Koi pond.....insane.



This house I was working was just gorgeous. Of course I was just making hot water for them......

__________________
"....And then we all switch places when I ring the bell"
-Adrock

JamesNLA

This setup supplied the house, the excess power was bought back. HO did it, because he didn't like paying the poco as much as he was. Now they pay him....every month. And it's one meter - spinning backwards!

__________________
"....And then we all switch places when I ring the bell"
-Adrock

robertc65

Well, I live on a 3 acre wooded lot and have and endless supply of wood to burn. I have plans to purchase a Dual fuel Propane / wood gassification boiler in the future for heat and hot water. I also have been doing some research into using wood gassification to power a generator. I'm quite sure in the next few years I'll be producing a good bit of power. I'm not thinking I'll be have enough to sell back, but it just got me thinking how does this really work. It sounds like you just push it back through the transformer which in turn will step it up to 7200 volts. Is it really that simple? I used to make small shocking devices by connecting a 9V battery to the secondary winding of a small power transformer and probes on the primary. Each time you break the circuit the xformer would step up the voltage from the 9V battery created a small shock. From this experiment I know you can run the power through the xformer in reverse I just didn't know that this also works on the power distribution grid.

mickeyco

3 acres doesn't sound like an endless supply of lumber, I don't think you'd get a whole lot electricity from 3 acres, it might be worth more, depending on the size and type, as lumber, plus it doesn't sound like a very "clean" way to make electricity. I doubt it would offset the price of the equipment.

mdshunk

Yes, I get a whole magazine devoted to what you're talking about. What you're intending to do is a "CHP Plant" (combined heat and power). Some sort of micro turbine, more than likely, for the genset.

Check out the free magazine "Distributed Energy", which is devoted to what you're talking about. http://www.distributedenergy.com/de.html It's probably the most technical rag devoted to this. It's geared more towards office buildings, labs, and critical sites.

747

robertc65 if you have 3 acres in a rural area i would look into placing a couple wind turbines which make power. I don't know how much they cost though.

ps. I would also run something like that buy a cpa. I sure the gov would give a tax writeoff or somekind of subsidy.

robertc65

My lot is actually just a small part of a large stand of oak trees in a forrest surrounding my house. A few of these a year get blown down from wind and just one all cut up seems like a whole lot of wood to me.