Inverter is over reporting the Grid Exports as compared to what Electricity provider is telling me

[grevox]

Hi,

I installed the Solar + Battery system a month ago and have been analysing the data over the past month and something feels off.

System details.

Solar: 13.3kw
Inverter: FoxESS KH10 (KH series, 10 kW single-phase hybrid inverter)
Battery: Make/Model: FoxESS EQ4800-L9, Total capacity: 41.93 kWh

I am with Amber (joined a week after the installation and joined their SmartShift VPP, still in learning mode).

I have Home Automation integration also with my system and I keep an eye on the data regularly to see if everything is ok.

I noticed a couple days after joining Amber that what FoxESS app tells me about the amount that I export to the Grid for that day does not match with what Amber is telling me. a little bit of difference is fine but the difference wht I have been seeing is huge.

I exported the inverter data for the past 10 days, got the usage data from Amber and compared the 2. Her's my findings.

Code: Select all

GRID EXPORT — FoxESS Inverter vs Ausgrid Smart Meter

Date         FoxESS (kWh)   Smart Meter (kWh)   Diff (kWh)   Ratio
2026-04-30          11.60                4.27        +7.33   2.72x
2026-05-01           8.50                3.11        +5.39   2.73x
2026-05-02           4.20                1.52        +2.68   2.76x
2026-05-03           8.40                3.10        +5.30   2.71x
2026-05-04           0.00                0.01        -0.01     —
2026-05-05          51.60               18.96       +32.64   2.72x
2026-05-06           2.50                0.91        +1.59   2.74x
2026-05-07           3.80                1.36        +2.44   2.79x
2026-05-08           4.40                1.61        +2.79   2.73x
2026-05-09          22.80                8.32       +14.48   2.74x
TOTAL              117.80               43.16       +74.64   2.73x

GRID IMPORT — FoxESS Inverter vs Ausgrid Smart Meter

Date         FoxESS (kWh)   Smart Meter (kWh)   Diff (kWh)
2026-04-30           0.30                0.23        +0.07
2026-05-01           0.30                0.20        +0.10
2026-05-02           0.20                0.24        -0.04
2026-05-03           0.20                0.23        -0.03
2026-05-04           0.30                0.25        +0.05
2026-05-05           0.20                0.16        +0.04
2026-05-06           0.30                0.26        +0.04
2026-05-07           0.30                0.23        +0.07
2026-05-08           0.20                0.23        -0.03
2026-05-09           0.20                0.19        +0.01
TOTAL                2.50                2.21        +0.29

The import numbers look perfectly fine but the export numbers are wrong. The inverter is over reporting the export numbers by almost a factor of ~ 2.73x consistently.

Something is wrong. I have asked my installer about this but also wanted to post here to see if others faced this issue what this possibly could be?

[Tambra]

Hi grevox,
I have the exact same system as yours, 13.3kw panels, KH10 and 41.93 Fox ESS battery. I am in Sydney, not sure where you are from ?
I checked my grid exports from the Fox Cloud2.0 app and they match up precisely to Electricty bill feed in. Over 99% accuracy which is a welcome surprise. I only had the system installed recently so that was checked against a single full 28 day bill cycle.
My problem is actually the grid imports. My Fox app is telling me I am using an average of 0.3kwh per day in imports. My Electricity supplier bill is showing an average of 1.0kwh per day grid imports. That is quite annoying as 1.0kw per day seems quite high. At this stage my battery has never run out and I don’t have any massive load periods where it needs to take grid imports.