Hi, I recently had installed a system of
18x Aiko Neostar 475 W solar panels.
Fox ESS KH 7KW Inverter
Fox ESS EP6 Plus 5.76KW battery.
Pre installation I used 7.77KW per day averaged over 99 days between Jan and May when home all day based on energy paid for through my utility provider.
Post installation my usage has averaged 11.82KW per day over 46 days between May and July as noted through the app.
My installer has spoken to Fox who have monitored my account and said they can see nothing wrong. They have also advised that the system energy does not appear as "usage" within the app as all the figures displayed are post operational use so somewhere since the installation, my property is draining and extra 4.12 KW on average or more than 50% extra per day.
Has anyone else seen this or can someone point me to what the issue is/might be.
Thanks
Site Admin
The K series is a large, high-performance inverter with fairly high operational cost in terms of self powering.
200 watt-hours ish to operate would give you what you're seeing daily totals-wise.
Ultimately, you should be better off as the panels will cover the operating overhead and then hopefully generate some nice surplus.
200 watt-hours ish to operate would give you what you're seeing daily totals-wise.
Ultimately, you should be better off as the panels will cover the operating overhead and then hopefully generate some nice surplus.
Community Admin / FoxESS Elite Professional
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3 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1 (Solar Mode)
1 x H1 Gen2 WL (Testing, Modbus and API development)
24 x HV2600 (62.4kWh), 2 x EP12, 2 x ECS2900
32 x 490w across 4 arrays
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Heatpump & Low Carbon Housebuild
Did I help you? Feel free to leave me a tip Book a zoom meeting for remote consultancy or help Switch to Octopus and earn £50 Subscribe to my YouTube channel3 x KH Hybird Inverters (Parallel Mode)
1 x H1 Gen1 (Solar Mode)
1 x H1 Gen2 WL (Testing, Modbus and API development)
24 x HV2600 (62.4kWh), 2 x EP12, 2 x ECS2900
32 x 490w across 4 arrays
2 x EV's (Tesla & Mercedes) Fox ESS EV Charger & Hypervolt Chargers
Heatpump & Low Carbon Housebuild
Thanks for the reply but the answer they gave me was that the power used by the system is not visible to the end user. All values in the app are post operational use so even if that is the case, what I see in the app should still reflect my 7.77KW average use.
Also are those figures taken into account when selling you your payback period.
I was told I'd generate about £1200 per year with about an 8 year payback period.
If those figures aren't taken into account, I can knock ~ £400 off of that thus turning my 8 year payback into about 12 years, a big difference.
Also are those figures taken into account when selling you your payback period.
I was told I'd generate about £1200 per year with about an 8 year payback period.
If those figures aren't taken into account, I can knock ~ £400 off of that thus turning my 8 year payback into about 12 years, a big difference.
My baseload with KH7 that Octopus bills me for, is 0.4kWh per 24hrs.
The Inverter uses some of the PV/battery to import little to no power from the grid.
Not sure how your import has increased that much?
The Inverter uses some of the PV/battery to import little to no power from the grid.
Not sure how your import has increased that much?
Using the Energy Stats approach that losses are Sources (solar + grid import + battery discharge) - Uses (house load + grid export + battery charge) my losses since install are about 6800 - 6200 = 600kWh.
(Different Inverter though)
House load on the other hand (if that is what you mean by usage) has gone down slightly post install (measured by App) vs pre install (taken from Octopus billing).
(Different Inverter though)
House load on the other hand (if that is what you mean by usage) has gone down slightly post install (measured by App) vs pre install (taken from Octopus billing).
Last edited by daveg on Wed Jul 15, 2026 5:42 pm, edited 1 time in total.
Thinking about this some more I'm not convinced the Energy Stats consideration of battery is needed in the long term. Losses are surely just In - Out. (Solar + Grid import) - (Home load + Grid export). In my case 4860 - 4560 = 300kWh since install.
Hi all
It's not my import that has increased, it is my "Daily Consumption" as displayed in the app v what I imported from the grid prior to my install.
My average import prior to solar was 7.77KW per day on average.
The app now shows my daily consumption as averaging 11.82KW ranging from about 10-15KW of which only about 0.2KW comes from the grid.
I am assuming that daily consumption is the apps totalisation of what I would've drawn from the grid had I not had any solar. Is this assumption incorrect?
It's not my import that has increased, it is my "Daily Consumption" as displayed in the app v what I imported from the grid prior to my install.
My average import prior to solar was 7.77KW per day on average.
The app now shows my daily consumption as averaging 11.82KW ranging from about 10-15KW of which only about 0.2KW comes from the grid.
I am assuming that daily consumption is the apps totalisation of what I would've drawn from the grid had I not had any solar. Is this assumption incorrect?
I'm no expert but I've formed a suspicion that the foxcloud app might include inverter consumption/battery losses in Load Consumption.
Reason - The value is always significantly higher than Home Consumption in the Energy Stats app.
Reason - The value is always significantly higher than Home Consumption in the Energy Stats app.
They usually quote the annual generation figures, and now you are seeing that some of this is diverted into your system to run it.
Reality is that this "lost" power is used by your system to run, but PV power still has a weighted cost, so can be used for ROI calculations.
Example, if you are "loosing" 4kWh each day, from your PV to running the system, if you assign 25p per kWh, then you are getting £365 pa of electric costs saved.
Reality is that this "lost" power is used by your system to run, but PV power still has a weighted cost, so can be used for ROI calculations.
Example, if you are "loosing" 4kWh each day, from your PV to running the system, if you assign 25p per kWh, then you are getting £365 pa of electric costs saved.