Generation reporting differnet to generation Meter

I have just been going through my FIT statements. Its a long way behind as SSE have taken 9 months to actually issue me a statement! I have been lookng in detail at the numbers over the last year as they are lower than previous years. Whilst going through this I have noticed that the meter readings I have supplied do not corrolate well to the values in the portal. I have been reviewing via using custom ranges on the reports and energy tile

My meter readings are up to 30% less than the portal is showing I have generated.

Anyone else seen this ?

I have a HY5 inverter

I've just compared my usage from this year to last (Solar installed End Dec 21) and we appear to have used less in some months and more in others (Taking into account export too) - some months we had holidays so less consumption overall. But we have in general "used" more in the summer than previously - whether that is due to the way GIVenergy calculates the solar I don't know - but the grid consumption on the portal is about 40kWh low compared to actual. (1750kWh actual)
So I can assume that solar will be similarly affected - but I'm happy enough with the errors as they seem to be reasonable.

Seye I use the Smart meter import and export values where money's concerned. I don't know how accurate the Givenergy portal values are as (IMO) they are only really of use when comparing one period with another. The EM115 specified for an installation is certified for consumer metering use but it is still processed by the Givenergy portal. Its value is really (again IMO) for the inverter to know whether energy is being imported, exported or balanced and that's about as good as it gets.

I know that the portal indicates my import at 0.1 to 0.5kWh/day compared to my smart meter which indicates 0.6-1kWh/day. These are very low values so I would expect there to be a larger error. My Smart meter export is reading 3495kWh since installation compared to 3374kWh on the portal. I'm getting paid for what the smart meter reads, so that's what I take notice of.

Just checked; grid import (1/3/22-31/8/22) 171kWh on smart meter and 45kWh on portal. The portal is good but I won't be using the data to challenge my energy supplier's bill.

Seye I have a HY5 inverter

Did you retrofit this to your FIT installation, or is this with separate PV. I know that you can change a faulty inverter on your FIT installation without affecting FIT payments.

Hi Seye
I have exactly the same problem, I have just got to the end of the 1st month since 1st aug commissioning
The portal tells me I used 273Kwh in Aug, my Meter readings tell me 391Kwh
It was my 1st month and I had considerable commissioning problems (now resolved thanks to Aaron at the Givenergy office)
But i was going to watch it closely.... in Sept as it is a huge worry if I a basing everything on a 30%-40% under measurement from the app

Seye My latest statement from Octopus vs a report showing the same period is pretty much accurate to for the export (316.5kWh on my bill vs 316.53kWh from GE) however the import is wildly out - no doubt because it's small numbers. I was charged for 4.6kWh but GE has me importing 1.58kWh, so 65% less than actual.

I wouldn't use the import readings as gospel, but the export are pretty much right.

Thank you Cdent, its my import figures that are wrong.....
I'll keep watchiing

Glamorgan I suggest you watch your energy supply meter rather than the portal. The portal is interesting but has nothing to do with your electricity bill. It would be nice to think that they were entirely in tune, but they're not!