Discrepancy on solar app Vs smart meter readings for power consumption from grid.

[Andyman75]

Hi all.

I have been scrutinising my system since install, as I have had a few weird readings going on overnight,, (that's being discussed in a different post)
But as such noticed a reasonable discrepancy between my reported energy import usages.

I've been preparing for winter and longer nights, more dependence on my battery backup.. I just switched to octopus go and have started doing a nighttime charge cycle on my battery.
Since doing so, I've noticed a discrepancy between what my solar app (growatt's shinephone app) and my meter usage shows through octopus' app.

As an example for the last 3 days on my shinephone app my reported usage (import from grid) has been :

10/9: 0.6kwh
11/9: 0.8kwh
12/9: 1.3kwh

Whereas on my octopus app, it shows usage as:

10/9: 2.66kwh
11/9: 3.19kwh
12/9: 4.25kwh

I'm all a bit new to both solar and smart meters, so I'm wondering am I being stupid,, or should those 2 figures not be identical?

And assuming it's not me having overlooked something, how do I figure out who to badger on this to get it sorted...
I'd like to think octopus are at fault, as otherwise I'll be paying more. Lol

Anyone had this behaviour before?

I'm a bit confused tbh....Help!

 

[Andyman75]

Ok, I've sussed one part of it... Unfortunately octopus are correct...
Hidden deep within submenu's on the shinephone app is another graph where you can select the specific option to view.
When I select "imported from grid" it shows a totally different figure to the one on the dashboard.

So not a clue what the point of the info on the dashboard is, as it's not even a vague estimate on what's actually going on,, certainly with the imported power from grid anyway.

 

[binky]

Apps are pretty pictures for guidance, meters are calibrated to BS standard as required by OFGEM. Not that meters can't go wrong, but, you will always find a difference between PV gear and a calibrated meter.

 

[user 36092]

Ok, I've sussed one part of it... Unfortunately octopus are correct...
Hidden deep within submenu's on the shinephone app is another graph where you can select the specific option to view.
When I select "imported from grid" it shows a totally different figure to the one on the dashboard.

So not a clue what the point of the info on the dashboard is, as it's not even a vague estimate on what's actually going on,, certainly with the imported power from grid anyway.

Could you tell me where its buried.
Im stuck finding it and the dashboard totals are useless to me.

 

[Andyman75]

Could you tell me where its buried.
Im stuck finding it and the dashboard totals are useless to me.

Hi matey.
Yes, ignore the graphs, they are nice visuals at best. Haha.


On the android shinephone app, it's a small italic 'i' button (indicating further information) and it lives to the right of the date , on the 'plant' screen, just above the useless multi colored bar graph.

If using apple app it may be slightly different.

Let me know if still having issues and I'll see if I can post a screenshot.

 

[user 36092]

Hmm yeah that’s what I had found already and it shows I used .70kwh yesterday when in fact I used 4.45kwh since I charged the battery overnight.
I’m beginning to wonder if they put the CT clamp that monitors import in the wrong place and as a result it doesn’t count charging the battery as import from grid.
Weirdly if I charge my car overnight the imported from grid will show that usage it just the charging the battery that doesn’t seem to show up.

 

[Tomr182]

Does it show the import for the battery once the energy has been discharged?

 

[user 36092]

Does it show the import for the battery once the energy has been discharged?

Not sure what you mean but basically the way I have it setup at the moment it fully charges the battery every night so most nights I use up to 6kwh (most times it’s not empty so it’s more like 3-4) but as you can see from the screenshot shine phone thinks I’m using much less.
Looking at it I think it’s reading the house usage during the period it’s in batt first excluding the energy being put into the battery so you still see the spike when I charge the car but every day it’s up to 6kwh under the real usage depending on how much I’ve bought to fill the battery.

 

[MHarv]

Check the location of the inverter CT Clamp

Most read import located at the incoming Live cable (Not Neutral) from DNO Meter to 100A Isolator then maybe to Black Henley Block for incoming Live and Neutral Tails
Then split depending on whether their is Main CU and Mini CU’s for ie EV Charger and Solar PV and Battery system

Check if CT Clamp is it between DNO Meter and Henley block on Live Tail?

Which way is the Arrow on the CT Clamp facing; facing towards Grid or towards the Consumer Unit which is important for your specific Inverter make setup.

You need the inverter manual maybe also battery manual downloaded from manufacturer’s website to confirm installation, settings and location of CT Clamp positioning on the setup.

What make model is your Inverter plus battery system?

 

[user 36092]

Check the location of the inverter CT Clamp

Most read import located at the incoming Live cable (Not Neutral) from DNO Meter to 100A Isolator then maybe to Black Henley Block for incoming Live and Neutral Tails
Then split depending on whether their is Main CU and Mini CU’s for ie EV Charger and Solar PV and Battery system

Check if CT Clamp is it between DNO Meter and Henley block on Live Tail?

Which way is the Arrow on the CT Clamp facing; facing towards Grid or towards the Consumer Unit which is important for your specific Inverter make setup.

You need the inverter manual maybe also battery manual downloaded from manufacturer’s website to confirm installation, settings and location of CT Clamp positioning on the setup.

What make model is your Inverter plus battery system?

So the CT looks to be correct, it’s on the live cable just after the meter.
There is an existing CT clamp before the meter that is for the car charger.
The inverter is a SPH6000 with a GBLI6532 6.5kwh battery.
I’ve read through the manual that came with it and nothing jumps out as being wrong.
The fact that the CT detects current going to the car but not the current going to the battery seems very odd since they both happen during the same overnight window.

 

[user 36092]

I’ve just opened the CT to check the arrow and it’s pointing away from the meter towards the consumer unit which is correct according to the manual

 

[MHarv]

So the CT looks to be correct, it’s on the live cable just after the meter.
There is an existing CT clamp before the meter that is for the car charger.
The inverter is a SPH6000 with a GBLI6532 6.5kwh battery.
I’ve read through the manual that came with it and nothing jumps out as being wrong.
The fact that the CT detects current going to the car but not the current going to the battery seems very odd since they both happen during the same overnight window.

Is that a CT Clamp (left of picture) before your meter?

If so what is the CT clamp for?

All CT clamps need to be after the DNO meter on the Live cable

 

[user 36092]

Is that a CT Clamp (left of picture) before your meter?

If so what is the CT clamp for?

All CT clamps need to be after the DNO meter on the Live cable

The one on the left is for the car charger, something to do with checking the incoming usage to make sure its not over drawing and was installed there by the installer of the charger before the solar system was put in.
Its location will have no affect on the growatt stuff.
The growatt CT is the blue on on the right.

 

[MHarv]

My Hypervolt 2.0 CT clamp is after the meter and solax battery system 11.6kW connected to solax X1 AC 3.6 inverter and iBoost+ CT clamp for info.

Plus I have solar PV array 5.2kW solax string Boost (does not take batteries)
All working today in a bit of sunny skies

Charging battery system from 83% to 91% so far today.

I would check with car charger manual for pacing the CT clamp before meter or after

It could be fine as is until you know

 

[MHarv]

There is no harm in changing location and direction of CT clamp just look at the apps and inverter to check if it was put on back to front.

 

[binky]

CT Clamp looks fine, but some inverters have to be set for clamp or meter type flow monitor. Have a read of the manual just to be sure there's not a setting in there somewhere

 

[johnb2713]

There is no harm in changing location and direction of CT clamp just look at the apps and inverter to check if it was put on back to front.

Are you sure? On mine if it's the wrong way round the inverter goes to full output, highest voltage etc. Remeber, the inverter uses the CT to set it's output voltage so that no import and no export takes place.

 

[MHarv]

That’s to check the system as you’ve found out

 

[johnb2713]

That’s to check the system as you’ve found out

The system is working therefore the CT must be the right way round, I'm not sure it would be a good idea to try reversing it.

 

[user 36092]

CT Clamp looks fine, but some inverters have to be set for clamp or meter type flow monitor. Have a read of the manual just to be sure there's not a setting in there somewhere

Pretty sure thats this setting and is set to CT already.