Substantial increase in consumption after new solar PV installation
Posted: Mon Jun 29, 2026 11:42 am
We had a solar PV system installed last Tuesday (June 23rd) - Fox-ESS KH7 inverter and EP12 battery.
We've noticed that our house energy consumption is now much higher than before the system was installed (I had been analysing our house energy usage for many weeks before the system was installed).
For most of the day the consumption figures being reported are now at least 300W higher than they were in the same timeslots prior to the installation. For example, prior to the installation our typical power consumption at 7am was around 300W. It now reports more than 600W consumption at 7am.
The screenshot below illustrates the issue – the three left-hand columns show our energy consumption last Sunday (June 21st - 2 days before the system was installed). The three right-hand columns show our energy consumption yesterday - Sunday June 28th. We did not use any major appliances yesterday (washing machine, dishwasher, etc). In fact we were away at the weekend, not returning until 2pm on Sunday, so the house was unoccupied for much of the day.
The figures for last Sunday (June 21st) were downloaded from the Octopus customer portal. The figures for yesterday were from the inverter (I have a device connected to it via the RS485 ports which monitors the data from it). The load figures from this device are also identical to the “Home” figure displayed in the Foxcloud app.
I thought I should check the accuracy of the inverter’s consumption reporting, so…… I have a smart plug which measures energy consumption. I plugged a 1200W hair dryer into it, It reported a power draw of 1,292W.
I then checked the power draw figure reported from the inverter. It had increased by 1,350W.
So the inverter seems to be reporting incremental increases in load reasonably accurately. It’s the increase in the base load of the house that I can’t explain.
Any ideas??
We've noticed that our house energy consumption is now much higher than before the system was installed (I had been analysing our house energy usage for many weeks before the system was installed).
For most of the day the consumption figures being reported are now at least 300W higher than they were in the same timeslots prior to the installation. For example, prior to the installation our typical power consumption at 7am was around 300W. It now reports more than 600W consumption at 7am.
The screenshot below illustrates the issue – the three left-hand columns show our energy consumption last Sunday (June 21st - 2 days before the system was installed). The three right-hand columns show our energy consumption yesterday - Sunday June 28th. We did not use any major appliances yesterday (washing machine, dishwasher, etc). In fact we were away at the weekend, not returning until 2pm on Sunday, so the house was unoccupied for much of the day.
The figures for last Sunday (June 21st) were downloaded from the Octopus customer portal. The figures for yesterday were from the inverter (I have a device connected to it via the RS485 ports which monitors the data from it). The load figures from this device are also identical to the “Home” figure displayed in the Foxcloud app.
I thought I should check the accuracy of the inverter’s consumption reporting, so…… I have a smart plug which measures energy consumption. I plugged a 1200W hair dryer into it, It reported a power draw of 1,292W.
I then checked the power draw figure reported from the inverter. It had increased by 1,350W.
So the inverter seems to be reporting incremental increases in load reasonably accurately. It’s the increase in the base load of the house that I can’t explain.
Any ideas??