How accurate are the import from grid metrics?

How accurate are the import from grid metrics? I'm asking because there's often a pretty significant difference between what my GivEnergy system says I've imported from the grid, compared to what my electricity provider says I've consumed from them.
For example, for March 2022 my GE report says I imported 185.67kWh but my electricity provider (EP) says 203.67kWh.

February was 319.37 kWh from GE, and EP was 326.16 and Jan was 495.42kWh from GE, 493.19kWh from EP. So those months look close enough to me to be accurate, but going back to 2021 there can be deltas of 20+ kWh some months.
So far for April GE says 44.12kWh and EP says 57.36kWh. There have been days in April where GE says I've imported 0.38kWh but my EP says 1.02kWh for the same day.

Just wondering if anyone else sees much of a difference between what their GE system reports and their actual provider? Is the difference the amount of power the Inverter/system draws to just run and that it's not included in the amount imported from the grid? If that's the case would I not expect roughly the same delta each month?

I might get corrected by someone but I believe this difference is the variance % of a CT clamp. A clamp will not give an exact reading for grid import. I do not recall what % variable is acceptable but I think it is 2.5 - 7% so even march looks ok, This months data however is worse, not sure why.

I have similar problem. The Givenergy shows nothing from the Grid. However, my house keeps drawing 1kWh per day.

I've got the same problem with my import being some 30% higher.

There are research articles on the website where this has been looked at.

Start reading with Octopus Energy by Phil Steele titled The perils of being a tech innovator
OK, they are talking about a Tesla system, but the problem is exactly the same.

Let's start building some data. I'll collate it and report back.

So, please post details of your system and the model of your Import meter. Also is it Smart.

I have a 4kWh PV system with GivEnergy hybrid 88.2kW battery and Import meter being Aclara SGM1411B with a Toshiba sender

Duplicated from a similar thread:

I just did a quick comparison of my meter data against the GE data (for imported energy). The GE data was about 94-97% of the meter value, for each full day. I did have one day when it was just 75%, but that was because GE did not capture all of the data from my system, because of a network/communication issue.

Have you checked that your GE data is complete for each day? If you have an unreliable internet connection between your inverter and the GE servers, this could result in them reporting lower values than reality.

Has there been any movement on what level of variation is considered acceptable? I’ve just compared the last 8 months of data for my GE, ME and octopus themselves, and there is a std deviation of 20-40kw between all of them over this period. Granted CT clamps are not exact and there is an expected difference, but surely not this much?

Umm, acceptable level of deviation is your personal choice. It's not laid down, however when equipment is quoted to be accurate then I would expect it to comply to the quoted values.
Our energy provider is now running a check meter against the Import meter.
To date it appears that the Smart Meter is over reading the import values.
Ofgem have recently published a report informing suppliers that micro generation equipment may interfere with Import meter accuracy, so the industry is beginning to recognise there may be a problem with power metering devices.

MikeReynolds hmmm. Anything I can do to improve this. You mentioned your supplier is running a check meter? Can one request this?

I done a comparison my end if it would help at all for my All-In-One unit

12PM for today not included as that is half a day.

I have had Solar since 19th July and been with Octopus since around 12th of August.

Yes, you can request your supplier to check your smart meter. They will want to charge you if the meter is not faulty.
My smart meter reads about 30% higher than the GivEnergy display.
So far the check meter shows figures much lower than the Smart Meter.
I have not been running a comparison against the GE at this stage, but the check meter seems to be a lot closer. Can't say yet if its within an acceptable tolerance yet.

MikeReynolds I personally would not take the figures reported in the GE portal or app as being gospel. There’s plenty of other posts here on the forum about inaccuracies in the reported data. The data is only sent to the GE cloud every 5 minutes so there is interpolation going on between the 5-minute readings.

If you use the BBC basic iOS ‘GivEnergy inverter’ app which reads the daily totals straight from the inverter. I’ve found this gives much more accurate figures, as does Home Assistant that polls every 5-15 seconds.
I’m now using the HA reports as being the more accurate and they correspond quite well to the smart meter readings.

geoffreycoan With the graphs I agree but the meter data is usually pretty accurate as long as you got a start and end time of around midnight.

geoffreycoan Can you advise how to run the BBC iOS app in this way. I am on Android and I have downloaded the BBC app and looking to find out how to connect to the inverter.
Thank you for your help.
Kind regards
Eric

emmoore103 Someone has written an app in BBC basic https://m.facebook.com/story.php?story_fbid=pfbid02tuw4U95kV3uJjUgb27rELLpPskX22qjsweQPyJWoJm4yjkJPLPjaQwYf2rQbi9Qkl&id=416716275106659 that connects to the GivEnergy inverter to show what your inverters are doing.

As far as I know its only been packaged for iOS. Whether you can get the code and install it on a BBC emulator on Android, no idea, sorry

There is a completely separate Android app though worth looking at https://play.google.com/store/apps/details?id=uk.rubikcube.invertermonitor&hl=en_US

geoffreycoan Whether you can get the code and install it on a BBC emulator on Android, no idea

I think I read on here that it's available on a wide range of platforms, inc.android, but I've not tried.

BBC Basic App:
iOS: https://apps.apple.com/gb/app/inverter/id6443976497
Android: https://bbcbasic.co.uk/inverter.apk
Windows: https://bbcbasic.co.uk/inverter.exe
MacOS: https://bbcbasic.co.uk/inverter.dmg
Linux: https://bbcbasic.co.uk/inverter.zip
Raspberry Pi (32-bit): https://bbcbasic.co.uk/inverter-rpi.zip
Raspberry Pi (64-bit): https://bbcbasic.co.uk/inverter-rpi64.zip
Source code: https://www.bbcbasic.co.uk/inverter_source.html

Probably should do a thread with all the different apps/code/methods in it really.

I have been reticent in adding a comment here whilst I was on firmware v8 as all my feed data was well just a mess, however 9 seems to have fixed that so here is my findings (no solar)

Per GE

Per Octopus Mini

So for me looks like 5% variation

hoggy Cool thanks, I didn’t know it was available for anything other than iOS.

For me the Smart meter reads about 0.1kWh per day higher than the GE values on average, both import and export read slightly high, this equates to about 4W constant load so well within the tolerance of an em115 clamp. It doesn't seem to matter the amount of import or export the difference is always around 0.1wkWh per day, so a small offset not a percentage variation.

PaDav6 Likewise. I use the givenergy inverter import and export meter readings to feed Home Assistant, and over a month comparing it to my Octopus bill, its within a kW which is more than good enough for me

Far more accurate than my Shelly EM CT clamps which I have on my FIT solar array and ASHP and are consistently 7-9% reading high