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Utility company visited me for exporting from my solar Off-grid growatt LVM-ES SPF 3000TL

Unless you have equipment to measure backfeed current with sufficient time resolution, you can't really be sure.
Definitely a concern. Have you tried what @Crowz and I are trying with your Victron ESS and seen if that addresses the feedback? By that I mean, pulling 200W either thru the inverter via settings or putting a load between the inverter and the grid to continuously suppress backfeed?
 
Definitely a concern. Have you tried what @Crowz and I are trying with your Victron ESS and seen if that addresses the feedback?
Victron tells us to set the ESS Grid Setpoint in watts to some wattage to help prevent feedback. They recommend like 50 or 100W.
I set mine to 500W. It won't matter, because the shedding of large inductive loads is larger than the offset.
In other words, it helps, but isn't sufficient to cover the feedback.

I don't know if Victron is better or worse compared to others, because the measurements would need to made independently to test that.
What it comes down to is the speed of the control loop inside the bidirectional inverter.
Victron is really conservative. Deye and Luxpower may be more aggressive, I don't know.

If you want absolutely no grid feedback, you've got to get rid of ESS on Victron.
My long term plan is full double conversion with chargeverters. Totally undetectable.
 
Some meters (like my old one) are technically "up to date" but can't understand bidirectional. Funny thing is my old digital meter could be remotely read, but they had to replace it with a bidirectional meter when I set up net metering and that one has to be manually read by a guy driving out to the house. Figure that one out 🤪

If I ever get my homestead property I'll closely inspect the meter there to see if it supports bidirectional or not. If not, then I won't worry about a teensy bit of leakage. If it does, then I'll have to figure something out. I don't intend to do net metering again as it may not be worth the hassle at that point. Depends on which power company I'd end up with.

Not sure if my Radian would actually leak any, or if it could totally avoid it.
 
dense moment here... but is the "backfeed" because of the 120v AC input for the charger? I'm going to assume so because that's the only connection I have to my main panel.

dang, wtf... i never considered that might be a possibility. thank goodness I have pushed back HARD on a smart meter. in fact, i'm paying $10/month to keep the old 'dumb' meter on on the house.
 
It has been 14-15 years back that the Co-Op upgraded to the new fangled remote reading digital meters from the old analog spinning disc type. Although it eliminated the contract meter readers job it really has few feature that the newer generation of "smart" meters have. It likely treats any export as simply additional power usage for the monthly Bill.

With this last month usage from the grid being 24kWh it is less than 1/10th of my previous usage so I wonder if I have a visit from the Co-OP in the works.

One thing for sure all those folks with the un-permitted cheap micro inverters are not helping the situation any.
 
Here's some datapoints I can provide after testing our Deye 8K
These are tests where we would switch off the following devices while monitoring the LCD display watching for the grid to switch to negative numbers. All values are in Kw, so -0.35 means 350 watts exported.

Zero export to load mode:

-0.35 oven toaster
NONE space heater
NONE dehumidifier
NONE vacuum
-0.11 water pump
-0.41 sauna

===================================

Zero export to CT mode:

-0.27 oven toaster
-0.05 space heater
-0.03 dehumidifier
-0.07 vacuum
-0.06 water pump
-0.34 sauna

So the worst offender was our sauna which pulls 1000W.

I first set Zero export power to 100W and the amount exported when switching off the sauna dropped from -0.34 to -0.03
Then I set it to 200W and it stopped showing up altogether.

This is hardly a scientific or exhaustive test and like @Crowz says, the smart utility meters may still detect export, but it's just what I've seen in a few limited tests.
 
Not sure if you had the job as lineman you would have that opinion.
The lineman, I am certain, ARE concerned about the lineman.

You can hate the "power companies" all you desire. Real people are working the lines and back feed is dangerous.
A good friend of mine, in America, worked as a lineman, and had stories to tell of colleagues who were linemen. They often do their work, intentionally, with live lines. They know very well what they are doing, and must take proper precautions to avoid electrocution. If they can work on live lines which have hundreds of thousands of volts, why should they fear to work, taking similar precautions, on a supposedly dead line that has some residual voltage in the 120-220v range?

Probably a totally separate issue, but I have also witnessed an extremely skilled welder arc welding on a steel pipe through which natural gas was flowing. He explained to me that it was safer NOT to turn off the gas, but to leave it "live" (flowing) because this helps to prevent overheating on the joint while he is welding. Thermal conduction. If there had been a massive explosion, I would not be here to tell the story because I watched from a few feet away. Because there is no oxygen running with the fuel in the pipe, there can be no explosion--but to the uneducated and/or less skilled, the risk seems much greater than it actually is. Of course, this, too, was in America. American ingenuity and skill should not be underestimated.

I tend to agree with those who see these strict regulations on electrical export as coming more from the angle of controlling (and punishing competition) than from purely a sense of safety. Nor is this the only industry where such overreach is to be observed. When was the last time the operation of a cell phone (as a cell phone, of course) actually endangered an aircraft? Industries like rules that favor their commercial interests. There is nothing new under the sun.
 
You setup this meter specifically to detect feedback?
I did it to test the ESS capabilities Victron offered. It lets me back-feed into the house (like zero-export for SolArk and others).
I thought a 10Hz meter would result in a quicker response to back-feed. It did, but still not fast enough.

A better way to do it is to put the CTs and voltage on an o-scope and trigger on back-feed, but the logic is tricky.
 
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I first set Zero export power to 100W and the amount exported when switching off the sauna dropped from -0.34 to -0.03
Then I set it to 200W and it stopped showing up altogether.
Bit slow here... what does that setting actually do? :unsure:
 
Bit slow here... what does that setting actually do? :unsure:
Hello SeaGal, nice to see you.
I found that by setting "Zero export power," my inverter would draw the exact amount I set it to continuously from the grid, whether I needed it or not.
 
Hello SeaGal, nice to see you.
I found that by setting "Zero export power," my inverter would draw the exact amount I set it to continuously from the grid, whether I needed it or not.
Sounds expensive - why would you want to do that. And where does the energy go if you're not using it? I think I am missing a piece of this jigsaw puzzle :(
 
Hello SeaGal, nice to see you.
I found that by setting "Zero export power," my inverter would draw the exact amount I set it to continuously from the grid, whether I needed it or not.
? Where does the grid power go if you have no loads meeting the 200w? This is a problem that I see with the concept of a minimum grid draw. Some of us have periods of near no power usage. (I am presently getting by at 32w house load.)
 
A better way to do it is to put the CTs and voltage on an o-scope and trigger on back-feed, but the logic is tricky.
I don't have an o-scope but I would really like to find a way to test backfeed as precisely as these smart meters used by the utilities. If anyone knows an accurate way to do that, please post what you know.
 
Sounds expensive - why would you want to do that.
Yeah you're right, it's not good from a consumption perspective, but we're just trying to find a way to prevent the backfeed / export this thread is talking about, and as I said it my case, it looked like it reduced backfeed in my tests.
 
? Where does the grid power go if you have no loads meeting the 200w? This is a problem that I see with the concept of a minimum grid draw. Some of us have periods of near no power usage. (I am presently getting by at 32w house load.)
I think then it would power the 32W with the grid and idle your solar (if your battery is full).

Basically, it will use up to that set amount from grid before using solar for anything. If you're not using any power, you're not really at risk of backfeeding.
 
OK, but if you have a grid-tied inverter it will accidentally export when a large load is turned off. As @ricardocello demonstrated in his graph above. The limitation is down to how quickly the inverter will respond to a change in load. From my experience, the speed of response also differs depending on whether it was powering the load from PV or battery.

Fortunately it's not an issue for us in the UK as everyone is permitted to export up to 16A (3.6kW), provided that the DNO has been informed and you are using approved / tested equipment.
 
I think then it would power the 32W with the grid and idle your solar (if your battery is full).

Basically, it will use up to that set amount from grid before using solar for anything. If you're not using any power, you're not really at risk of backfeeding.
Hmmm... I will have to think about this for a bit. My first assumption is that export would be much more likely during low household demand.
 
Wow that is awesome, I'm working to get my house below 10X that value while we sleep.
I'm at about 130-140W per hour overnight for main fridge/freezer, a small chest and full size upright freezer in the basement, the cable router and AP, and NAS.

However it does surge beyond that especially if a defrost cycle kicks off.
 

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