Feeding home made power back to the grid

[crinkles]

on the 1st of January a new scheme has been set up in our state where you get paid 60 cents per kw.hr of electricity you feed back into the grid. this is about 3 times the peak period charge for electricity.

When looking at complete solar and wind systems you can get the grid feed systems and self sufficient systems with a battery bank. the latter is near twice the price (e.g. 70k vs 35k). Obviously if you were too far from the grid you'd need the batteries.

i was wondering how your power is transferred to other customers? firstly you would generate DC, which needs to be made AC to an inverter, then fed into the grid, but what about voltages??? can a house 1000 miles away make use of the energy i generate or would it effectivley be distributed to the adjacent properties? just some thoughts. shannow may just be the man for this...

 

[JHZR2]

I think some of that is is still TBD. The grid is assumed to be an infinite bus, there are always consumers on the other end.

Ultimately, this is why grid-tied energy storage is such a big thing, because 120/240/480 distribution may have shortcomings when it comes to LOTS of folks being producers.

There are often times when the regional distribution companies have to effectively pay people to be consumers, even now, because it is difficult to throttle a power plant. Imagine if an irregular, unsteady generation source comes into play?

Shannow is surely the right person for this, but AFAIK,the grid is an infinite bus, so for the time being, all production will find a consumer "nearby".

 

[labman]

Electricity will follow the wires wherever the resistance is the lowest, back through the meter, the transformer on the pole, the one back the substation, and on. Most likely it will end up in your neighbors house. There will have to be a system to regulate the voltage and match phase to the the grid.

I have sort of been interested it just how they set it up since I learned what you need to do to legally connect your own generator into your home wiring in the event of a power outage. I am sure there will be the expense of switching equipment. I am sure most homeowners won't have a system capable of running much of the grid when it is down.

 

[Michael_P]

I'm sure the linemen just love to hear this. Thinking the power is shut off and then they get zapped from the back side of the line where no power is supposed to be. I have heard where linemen will short lines running from transformer to house for about 10 seconds to kick the breakers on the house or generator not to get shocked while working on lines. If its an older generator, it fries the head or stalls the motor. Either way they have a limited amount of time before the homeowner fixes the issue. People can be charged with back feeding and energizing lines around here with endangering utility workers.

 

[UNC017]

Originally Posted By: Michael_P
I'm sure the linemen just love to hear this. Thinking the power is shut off and then they get zapped from the back side of the line where no power is supposed to be.


Any system that feeds power back INTO the grid should be configured so that it uses the grid as a phase reference. Disconnect the incoming feed, it loses its phase reference, detects the drift, and shuts down its power back-feed.

There are regulations in place governing how back-feeding power from home generation units works expressly to protect linemen from unintended back-feeding. Safety systems can always fail, which is why the lineman's mantra is "if it isn't shorted, it isn't dead." The normally put shorting jumpers both "up-line" and "down-line" from where they're working as a secondary protection.

 

[The_Jeff]

I smell a moneymaking scheme where you backfeed your neighbors 20c electricity through your meter, get paid 60c and split the profits.

 

[crinkles]

bump. didn't think of the linemen!

 

[Vikas]

Or better, get a *huge* battery and store the electricity and feed it back. It is like perpetual motion machine

- Vikas

 

[Papa Bear]

Originally Posted By: Michael_P
I'm sure the linemen just love to hear this. Thinking the power is shut off and then they get zapped from the back side of the line where no power is supposed to be. I have heard where linemen will short lines running from transformer to house for about 10 seconds to kick the breakers on the house or generator not to get shocked while working on lines. If its an older generator, it fries the head or stalls the motor. Either way they have a limited amount of time before the homeowner fixes the issue. People can be charged with back feeding and energizing lines around here with endangering utility workers.


When the electricians at Chrysler had to work on the bus, they shut it down and wrapped chains around it ... that prevented any unwanted current from "ruining their day".

 

[Torino]

In short, the grid is a HUGE battery. John--Las Vegas.

 

[Shannow]

Originally Posted By: crinkles

i was wondering how your power is transferred to other customers? firstly you would generate DC, which needs to be made AC to an inverter, then fed into the grid, but what about voltages??? can a house 1000 miles away make use of the energy i generate or would it effectivley be distributed to the adjacent properties? just some thoughts. shannow may just be the man for this...


crinkles, think of the grid as a great big swimming pool. Each customer is sitting somewhere with a straw, and each producer is feeding fluids into it.

You pay your retailer for "green" energy, and he pays someone to pour guava juice into the pool.

Meantime, there's a dirty big coal fired plant near you, pouring in...whatever.

You are paying extra to add your preference to the pool, but are consuming whatever is fed into the pool closest to your straw.

The 60c thing, if you can afford the up front costs, is a serious goer, and has very very quick payback... it's a boondoggle, in that you are getting paid 3-4 times what any other generator would get for a renewable energy certificate, and nearly double what a generator would get paid for the power costs PLUS a renewable energy certificate.

Solar works well here, as all of our peaks on the eastern seaboard align.

Maybe they are factoring in the costs of construction of power stations in rewarding the solar householders...dunno.

It's a two meter system. One meter for outgoing solar, 1 meter for incoming energy, even if it's that which you just sent out.

 

[PandaBear]

Originally Posted By: eljefino
I smell a moneymaking scheme where you backfeed your neighbors 20c electricity through your meter, get paid 60c and split the profits.


If you are able to throttle generation, the best would be to use it to power dedicated appliances like water heater, refrigerator, lighting, computers, or whatever, than to send it out to the grid.

What is the power source?