Over 50 and Feeling the Frustration

[manolothai]

32 minutes ago, MJCM said:

My Guess is that you have something called Ghost Export and the Electronic meter is registering it.

 

You say, you don't export, but there is something called "Ghost Export". I have noticed that in our setup and on the day the meter reader comes we have a FAN running on a circuit that bypasses the solar and thus make the meter go forward ever so slowly, the rest of the house is "powered" by Solar.

 

 

I have ordered the automatic switch.

 

I will install it in a few days and set the inverter offgrid, so any ghost export is impossible since I won't be anymore grid tied. 

Edited June 11 by manolothai

[Crossy]

Yeah, Ghost Export is a known problem with electronic meters and one solution is to go off-grid, only going on-grid when the solar is dead.

 

Some inverters allow you to set a minimum grid draw of a few watts which should offset any ghost. 

 

Members on another, US-centric, solar forum are noting that their electronic meters are actually saying "error" in the event of even a tiny ghost (along with threats to remove the meter).

 

[lom]

57 minutes ago, Crossy said:

Some inverters allow you to set a minimum grid draw of a few watts which should offset any ghost. 

Deye inverters has what I consider to be the opposite setting, the zero-export power setting which  I haven't been able to notice any difference when changing the value. From the manual:

 

"Zero-export Power: for zero-export mode, it tells the grid output power. Recommend to set it as 20-100W to ensure the hybrid inverter won' t feed power to grid"

 

I did have a problem with ghost import though when previously running the inverter in on-grid mode, there was a continuous  import of 30-40 W with a few short daily peaks up to a few hundred watts.

This import was not needed, there was enough solar and battery power to account for the AC load.

These few daily import peaks always occurred at the same time as a PV current dip or AC load peak and were probably just inverter having difficulty in decision making. They were probably very short but SolarMan only has a resolution of 5 minutes so it is not possible to see their duration. Could be that it is a software bug and that I need to update my inverter..

 

Anyway, this ghost import added up to nearly 1 unit/day so that was also another reason for running off-grid with an ATS.

 

Edited June 11 by lom
formatting

[manolothai]

8 minutes ago, lom said:

Deye inverters has what I consider to be the opposite setting, the zero-export power setting which  I haven't been able to notice any difference when changing the value. From the manual:

 

"Zero-export Power: for zero-export mode, it tells the grid output power. Recommend to set it as 20-100W to ensure the hybrid inverter won' t feed power to grid"

 

I did have a problem with ghost import though when previously running the inverter in on-grid mode, there was a continuous  import of 30-40 W with a few short daily peaks up to a few hundred watts.

This import was not needed, there was enough solar and battery power to account for the AC load.

These few daily import peaks always occurred at the same time as a PV current dip or AC load peak and were probably just inverter having difficulty in decision making. They were probably very short but SolarMan only has a resolution of 5 minutes so it is not possible to see their duration. Could be that it is a software bug and that I need to update my inverter..

 

Anyway, this ghost import added up to nearly 1 unit/day so that was also another reason for running off-grid with an ATS.

 

 

@lom on deye you moved al the house to the backup port because as I understood that's the only way to run deye offgrid, do you confirm?

[Muhendis]

1 hour ago, Crossy said:

Ghost Export is a known problem

It strikes me that this "Ghost power" is a design shortfall.

If zero export is called for then why not incorporate a mechanical device like a control relay to isolate the inverter.

These inverters are getting exorbitantly expensive so they should concentrate a bit of resource on Ghost power elimination.

Perhaps call in Ghost Busters (did someone already think of that?). 

Edited June 11 by Muhendis

[Hummin]

5 hours ago, Crossy said:

 

Even if he was grid-tie (he's not, the ATS handles that), every domestic level grid-tie inverter has island-protection to prevent it back-feeding into a dead grid. It's an absolute requirement.

 

Note that exporting energy to a live grid (no hazard) is not the same as back-feeding to a dead grid (potential hazard to linemen).

 

If your inverter is on the "approved" list rest assured that, assuming it is correctly installed, it will never back-feed into a dead grid.

Thank you

[lom]

42 minutes ago, manolothai said:

@lom on deye you moved al the house to the backup port because as I understood that's the only way to run deye offgrid, do you confirm?

Yes, or at least it was the simplest way of isolating the solar equipment from the grid. I have not tested but I think the grid port doesn't get any power from the inverter during grid power cuts.

I basically run the whole house on a big UPS 🙂

[manolothai]

15 minutes ago, lom said:

Yes, or at least it was the simplest way of isolating the solar equipment from the grid. I have not tested but I think the grid port doesn't get any power from the inverter during grid power cuts.

I basically run the whole house on a big UPS 🙂

 

When batteries are depletd and ther's not enough production or for some reason the demand exceed the production + batteries availability the inverter goes off and switcher automatically turn into grid, and when inverter provide again energy it will switch back autmatically?

There's a point here. Is not possible that it starts to loop like that: switch to grid because the load is too high, inverter recover a normal state because there's not load connected anymore, switch to inverter, but the load is too high, so inverter cut off again and switcher switch to grid and so on again and again in loop?

[Crossy]

44 minutes ago, Muhendis said:

It strikes me that this "Ghost power" is a design shortfall.

If zero export is called for then why not incorporate a mechanical device like a control relay to isolate the inverter.

These inverters are getting exorbitantly expensive so they should concentrate a bit of resource on Ghost power elimination.

Perhaps call in Ghost Busters (did someone already think of that?). 

 

Wouldn't that make it an off-grid hybrid then, just spend less money 🙂 

 

The issue affects the hybrids that synchronise the output to the grid (so called on/off grid hybrids) so that the grid can seamlessly provide any shortfall from the solar, like a grid tie would.

 

The problem occurs when a large load goes off, the electronics doesn't react fast enough and a short burst of export occurs. A disc meter probably wouldn't notice at all but the electronic meters can and do.

 

Note that I understand that @MJCM actually had a constant, although small, export (meter was actually moving visibly) even when the inverter said zero. Fixed with a small constant load (fan).

 

[lom]

2 hours ago, lom said:

 

I did have a problem with ghost import though when previously running the inverter in on-grid mode, there was a continuous  import of 30-40 W with a few short daily peaks up to a few hundred watts.

and by describing this in a post I got to think about it a bit more and this is probably the reason for the import:

 

Part of the inverter is the AC generating circuit which in on-grid mode follows the grid voltage and generates the same voltage itself, in my case the grid is 224V, 229V, and 230V  on the three phases and that is also what I get on the backup port when grid connected. When off-grid mode the voltage on the backup port is 230V on all three phases.

So I think that the AC circuit takes it power from the grid when in on-grid mode and that is my ghost import.

 

Edited June 11 by lom

[lom]

1 hour ago, manolothai said:

When batteries are depletd and ther's not enough production or for some reason the demand exceed the production + batteries availability the inverter goes off and switcher automatically turn into grid, and when inverter provide again energy it will switch back autmatically?

Yes but the looping  is not something I have experienced. My inverter is rated 12KW (and can be overloaded quite a bit for short periods) and max consumption I've seen is 7-8KW.

Should the ATS start to loop then I can always set the ATS to manual mode temporarily.  Or flip the unmarked breaker in my panel which provides grid power to the inverters grid port😁  but then I'm of course grid-tied, not off-grid, and will also have the 1 unit/day inverter consumption.

I want to avoid that, it is not about the money it is a principle..

 

 

 

Edited June 11 by lom

[Muhendis]

43 minutes ago, Crossy said:

The problem occurs when a large load goes off, the electronics doesn't react fast enough and a short burst of export occurs. A disc meter probably wouldn't notice at all but the electronic meters can and do.

So it sounds like a fast feedback loop to monitor the inverter output cycle by cycle would be required to control this instability as I understand it.

[Pink7]

On 6/10/2024 at 9:46 AM, lom said:

 

If you operate your inverter in off-grid mode then I can't see that you need to register with PEA, I use an Automatic Transfer Switch in a way so that the inverter has no direct grid connection, it is not grid-tied.

Same here !

 

Pink

[dasekel1]

I hear that PEA do not allow to feed in surplus solar generated power into the grid if one has batteries? I have a 10 kWh system and just got my contract to feed-in energy and was planning to buy some batteries, but the provider says that is no longer allowed by the PEA. Anybody else heard about this? What another nonsense if that is true.

[manolothai]

They are ridiculous. I just went off grid months ago. They can come to collect the meter anytime. 

[Crossy]

1 hour ago, dasekel1 said:

I hear that PEA do not allow to feed in surplus solar generated power into the grid if one has batteries? I have a 10 kWh system and just got my contract to feed-in energy and was planning to buy some batteries, but the provider says that is no longer allowed by the PEA. Anybody else heard about this? What another nonsense if that is true.

 

They may be worried about people buying cheap-rate energy using a TOU meter then selling it back as peak rate during the day. I'm not convinced that would be remotely profitable but ...

 

We're just running off-grid, no hassles from PEA.

[Muhendis]

2 hours ago, dasekel1 said:

but the provider says

What provider?

I would think that PEA  would have no knowledge of your battery installation 'til you tell 'em.

Even so, I can't imagine why PEA would be interested in what your power source was be it batteries or solar.

In my opinion and for what it's worth, I think It would be pretty daft to drain your batteries and wear 'em out for the sake of a few baht of feedback tarif.

 

I have been off grid since the beginning of time which, for some believers, was 10,000 years ago but for me, was a massive 12 years ago.

Mind you I still enjoy a few Amps from time to time from those wonderful fossil fueled PEA generators.

I have a mini rice mill which will run quite happily on solar but for the stall current.

That happens a few tymes per day. I'm still on the learning curve.