Question regarding where power goes

[hhsting]

I have pV system and its PV AC main disco is connected ahead of building main service disconnect.

Question power generated from the PV system does it go from the solar panels to the utility grid and back to the building main service disco which then powers the building solar panels are on or it cannot come back to the building in on which the solar panels are to power the building?

Does anyone know?

 

[Fred B]

I have pV system and its PV AC main disco is connected ahead of building main service disconnect.

Question power generated from the PV system does it go from the solar panels to the utility grid and back to the building main service disco which then powers the building solar panels are on or it cannot come back to the building in on which the solar panels are to power the building?

Does anyone know?

On a grid tied system if house is using as much or more energy that being produced all the solar production gets used, lowering amount being metered. If house is using less than being produced the balance not used get back fed to the utility through the meter, in essence spinning the meter backward (but not really). Think that is the basis of net metering.

 

[GoldDigger]

Which way a particular stream of power goes is a useless question to ask. Think instead of net power to building,
It is totally equivalent in every way if
a. The power goes out to POCO and all of the building power comes from POCO. Net to you is consumption minus production.
b. The power goes to the disco and back into the building and reduces the amount you buy from POCO. Net to you is consumption minus production.

The point of inetrconnection only matters if it goes out to POCO through a separate meter with a different rate, rather than through a net meter.

 

[paulengr]

Which way a particular stream of power goes is a useless question to ask. Think instead of net power to building,
It is totally equivalent in every way if
a. The power goes out to POCO and all of the building power comes from POCO. Net to you is consumption minus production.
b. The power goes to the disco and back into the building and reduces the amount you buy from POCO. Net to you is consumption minus production.

The point of inetrconnection only matters if it goes out to POCO through a separate meter with a different rate, rather than through a net meter.

This is true even on the utility grid. I worked in a plant in New Jersey that bought their power from Touchstone in Connecticut.

In net metering the effect is that every kwhr produced is knocked off your usage, as if you never used it. In non-net metering effectively they credit you as a contract producer. They still make money off the difference between what they pay and what they charge. The utility makes just as much as all that solar.

 

[Carultch]

I have pV system and its PV AC main disco is connected ahead of building main service disconnect.

Question power generated from the PV system does it go from the solar panels to the utility grid and back to the building main service disco which then powers the building solar panels are on or it cannot come back to the building in on which the solar panels are to power the building?

Does anyone know?

You don't really know where any individual "packet" of energy goes. Some leaves your service and feeds your neighbor's service, some is drawn in from the service, and it is all happening simultaneously. We may say that it "first feeds the on-site loads, and then exports the surplus to the grid", but this is a statement of bookkeeping rather than reality. Both energy exchanges are concurrent, and all that we can really measure is the net flow of power at any given point. The term net means total. More specifically, unlike gross that also means total, net means a total that keeps track of sign and/or direction, as it adds up quantities.

At any given instant, all a meter can measure is the instantaneous voltage and instantaneous net current, both of which are signed. From these measurements, it calculates the net kilowatts flowing through it, and the sign of that kilowatt value to keep track of direction. No individual meter can tell the difference between the case of 4 kW consumed on a service that doesn't have any generation, and the case of a 2kW source offsetting part of a 6 kW load. Both cases are a measurement of net 4 kW being consumed. Once you mix sources and loads in the same infrastructure of busbars and circuits, the only kilowatts you can measure through any given point, are the net kilowatts. You would need to measure prior to the point of interconnection, to be able to keep track of your gross generation and your net export.

The meter can keep track of the signed power in two separate registers as it accumulates kilowatt-hours in each one, such that it treats imported energy differently than exported energy. Or it can track of them in the same register, such that all kilowatt-hours are valued equally, in what we call net metering. Some meters are set up to be secure-forward, such that no matter which way power flows, it counts as consumption. There are also meters that ignore exported power, and only measure imported power.

 

[wwhitney]

You don't really know where any individual "packet" of energy goes.

Moreover, I would say it is undefined. I.e. it's not that it's knowable but we don't know; it's that the question is unanswerable.

Cheers, Wayne

 

[LarryFine]

Well, I know, but I'm not talking.

 

[Fred B]

I have pV system and its PV AC main disco is connected ahead of building main service disconnect.

Question power generated from the PV system does it go from the solar panels to the utility grid and back to the building main service disco which then powers the building solar panels are on or it cannot come back to the building in on which the solar panels are to power the building?

Does anyone know?

Once that electricity leaves the solar panel are those specific electrons powering your dishwasher? No way to know unless the dishwasher is not tied to grid thru main service but only tied to the solar panel, then you know. Otherwise it is just one more electron moving thru the system.

This is one of the complaints I've had for POCO billing that if I select that I want to use "Green Energy" they'll charge me more per kWh than if I say just give me power. There is no way to know that those electrons coming into my home was generated by "Green" resources vs a coal fired generator. One transmission line, they don't change a meter, no kind of buffer that'll only allow power generated by "Green" source, nothing, but they are willing to charge me more. I say I am supporting Green energy every time I turn my light on or run my AC. Until they can ensure that I am only getting power generated solely from "Green Energy" production I see no need to pay more for it.

 

[Hv&Lv]

Once that electricity leaves the solar panel are those specific electrons powering your dishwasher? No way to know unless the dishwasher is not tied to grid thru main service but only tied to the solar panel, then you know. Otherwise it is just one more electron moving thru the system.

This is one of the complaints I've had for POCO billing that if I select that I want to use "Green Energy" they'll charge me more per kWh than if I say just give me power. There is no way to know that those electrons coming into my home was generated by "Green" resources vs a coal fired generator. One transmission line, they don't change a meter, no kind of buffer that'll only allow power generated by "Green" source, nothing, but they are willing to charge me more. I say I am supporting Green energy every time I turn my light on or run my AC. Until they can ensure that I am only getting power generated solely from "Green Energy" production I see no need to pay more for it.

If you want green energy, it costs more.
If you check green energy, it has to be paid for by someone. If you check green energy and don’t pay more, then that green energy cost has to be shared or subsidized.
POCO complaints are directed at the wrong people. Complain at the green energy people. They are subsidized and still make a lot of money by charging more than avoided wholesale cost.

You go to the grocery store and pay more for “free range” chicken. How do you know that chicken has ever been outside on grass? Chances are that bird never left the grow house. Do you complain to the grocery manager?

 

[Fred B]

If you want green energy, it costs more.
If you check green energy, it has to be paid for by someone. If you check green energy and don’t pay more, then that green energy cost has to be shared or subsidized.
POCO complaints are directed at the wrong people. Complain at the green energy people. They are subsidized and still make a lot of money by charging more than avoided wholesale cost.

You go to the grocery store and pay more for “free range” chicken. How do you know that chicken has ever been outside on grass? Chances are that bird never left the grow house. Do you complain to the grocery manager?

You're right and I don't buy the free range chicken or the eggs marked that way, for tha reason, are they really what it claims to be. I will however buy from the farmer directly and more than willing to pay more for their product. Farm stand for fresh corn or other produce. Grocery has at least 3 days from farm to shelf for "fresh" produce (likely even more).

 

[bwat]

This is one of the complaints I've had for POCO billing that if I select that I want to use "Green Energy" they'll charge me more per kWh than if I say just give me power. There is no way to know that those electrons coming into my home was generated by "Green" resources vs a coal fired generator. One transmission line, they don't change a meter, no kind of buffer that'll only allow power generated by "Green" source, nothing, but they are willing to charge me more. I say I am supporting Green energy every time I turn my light on or run my AC. Until they can ensure that I am only getting power generated solely from "Green Energy" production I see no need to pay more for it.

Although you are correct that you don’t really know where it comes from, it’s not complete hogwash what they’re doing. When you check the box, essentially your house load goes into a load forecasting pool (I believe at the ISO level) that must be supplied by green sources, even if it’s more expensive to do so. Normally, cost is king.

 

[jaggedben]

...

This is one of the complaints I've had for POCO billing that if I select that I want to use "Green Energy" they'll charge me more per kWh than if I say just give me power. There is no way to know that those electrons coming into my home was generated by "Green" resources vs a coal fired generator. One transmission line, they don't change a meter, no kind of buffer that'll only allow power generated by "Green" source, nothing, but they are willing to charge me more. I say I am supporting Green energy every time I turn my light on or run my AC. Until they can ensure that I am only getting power generated solely from "Green Energy" production I see no need to pay more for it.

Just to pile on...

This is a little like saying 'if they raise my taxes to pay for road construction I have no way of knowing if it gets spent on road construction'. It's valid to a point, in that it's very difficult for the average citzen to track where the money goes. But if you were to press hard enough there is information available and a 'way to know.' And it doesn't matter much if the tax money goes into an account that holds money for all sorts of other things. What matters is whether the amount that goes in 'for road construction' is what got spent on road construction. As others have alluded to, if you are motivated to pay for green energy, do you really need to care if the electrons coming into your meter are the green ones? You don't. What you are paying for is for someone to push that amount of green electrons on the grid.

 

[Hv&Lv]

You're right and I don't buy the free range chicken or the eggs marked that way, for tha reason, are they really what it claims to be. I will however buy from the farmer directly and more than willing to pay more for their product. Farm stand for fresh corn or other produce. Grocery has at least 3 days from farm to shelf for "fresh" produce (likely even more).

“free range chicken” is simply the exact same houses as non free range, with a ~18X20 side door cut in about 18” above the floor, with a ramp to get out and back in. Outside is a small fenced in area.
The door has to be open only after the chickens are (I think) 45-60 days old, AND the temperatures outside are between 65-80 degrees(or somewhere around those temps.) they all have to be back inside at nights.
IF a chicken goes outside, it can’t find its way back in and the farmer has to put it back in at some point in the day.
Ask a farmer, the chickens don’t leave the house unless it gets “lost” wandering and finds itself outside...
I have talked to one that’s been doing free range for 3-4 years now. Only had two birds out of all the flocks he has raised to go outside.
But they can... that’s the point.

OK. Back to the original thread..

 

[Grouch1980]

In non-net metering effectively they credit you as a contract producer.

Is this what's considered a 'gross metering' setup?

 

[Carultch]

Is this what's considered a 'gross metering' setup?

I suppose you could call it that. Whether others would recognize it or not, is another matter entirely. But yes, just as the term gross implies, it would total the positives separately from the negatives, and treat the two totals differently.

What it would mean is that you have two separate energy registers inside your meter, that track imported and exported energy separately. This way a different dollar rate can be assigned to energy you import and energy you export. The import dollar figure is likely greater than the export dollar figure, because you pay for the transmission and distribution when paying for what you consume. But with what you export, you may only get paid for the production, and not for other costs on the bill that are associated with the rate per kilowatt-hour consumed.

So if that is the policy you have, it is in your interest to self-consume what you produce on site at the same time you produce it. This is due to value of each kilowatt hour produced being equal to what you don't have to spend on buying that energy from the utility. Whereas energy you export, gets credited at a much lower rate.

 

[hillbilly1]

“free range chicken” is simply the exact same houses as non free range, with a ~18X20 side door cut in about 18” above the floor, with a ramp to get out and back in. Outside is a small fenced in area.
The door has to be open only after the chickens are (I think) 45-60 days old, AND the temperatures outside are between 65-80 degrees(or somewhere around those temps.) they all have to be back inside at nights.
IF a chicken goes outside, it can’t find its way back in and the farmer has to put it back in at some point in the day.
Ask a farmer, the chickens don’t leave the house unless it gets “lost” wandering and finds itself outside...
I have talked to one that’s been doing free range for 3-4 years now. Only had two birds out of all the flocks he has raised to go outside.
But they can... that’s the point.

OK. Back to the original thread..

Your correct, the chickens tend not to go out unless they are lost. On the farm I’m hooking up the generator to automatic transfer switches, they leave the end door into the egg room open fairly often. The chickens just stand there and look at you. They don’t attempt to go out the door. If you scare them, they will go out, but otherwise, they are content to stay inside.

 

[zbang]

A bit late, but here goes-
I explain the whole "where does it come from, where does it go" by considering the grid as a shallow bucket of water. The consumer's solar panels dribble into the bucket right next to their draw from the bucket, that draw might water from the panels, might not, but it doesn't matter. Somewhere on the other side of the bucket are pipes pouring water in from all the power producers including the "green" ones, but all just water. Since we how how much each producer puts into the bucket, how much each user pulls out, and who asked for green, we can figure out who to bill for what.

 

[wwhitney]

Nice analogy.

And to belabor my earlier point, for the analogy I find it important to consider the water as a continuous medium that can't be tracked once it goes into the bucket. With an actual water bucket, you could put a little dye in one of the inputs and track where it ends up going. With electrical energy, that's not possible.

Cheers, Wayne

 

[zbang]

Wait, don't all those electrons have serial numbers??
(Saying "clear water" is a good extension.)

 

[hhsting]

Wait, don't all those electrons have serial numbers??
(Saying "clear water" is a good extension.)

Who told electric current is just electrons? Electric current is movement of charged particles and their are two: protons and electrons. So then protons can also be involved or are moved.