FoxESS Community - Owners & Installers Forum

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

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.

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.

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?

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).

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?

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.

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.

@daveg what is the energy stats app please?
@MaterialBarracuda48 Not sure I follow your logic.
If the system uses 4K per day to operate you are not saving £365 per year as such because that is energy you wouldn't have previously used. What you are doing is losing £365 from your ROI.
My system cost 10K and I was told it would return me a profit (based on my actual usage at the time) of ~£1200 per year so a payback of about 8 years.
Because the system is costing £365 per year to run, my actual profit is now only £835 so my payback period is now around 12 years, a big difference to what I was told.
It's a bit like someone selling you a machine that can print one five pound note per day for £5000 and telling you it will pay for itself in 1000 days but forgetting to tell you it costs £2.50 per day in electric to run. Yes it still makes a profit of £2.50 per day but the payback is now 2000 days, not the 1000 you thought.

I guess it's a PoV thing.

If you generate 5000kWh in a year, export 2500kWh at xxp per kWh there is part of your ROI.
The remaining 2500kWh doesn't have zero monetary value, you have to assign a price per unit (at least I do)

It doesn't matter if 500kWh of the remaining 2500kWh is used by your system to power your inverter, it is still money generated.

Energy Stats is another app for monitoring FoxESS solar/battery systems. Here is the android link
https://play.google.com/store/apps/deta ... nergystats
It includes a specific estimate of inverter consumption.
For my system yesterday it says that inverter consumption was 1.9kWh.
(I have 8 of the same solar panels that you have 18 of, 18/8x1.9=4.3kWh).

Thanks, have downloaded the app but need to generate api. It tells me not to use v2 of the website but https://www.foxesscloud.com/login wont accept my username and password. If I try to register, it tells me that my email has already been registered. I don't have an alternate email so any ideas on how to log in to https://www.foxesscloud.com/login or otherwise generate an api?

The v1 site and v2 (new) site use the same login details.
You may have to follow the "forgot password" choice for a reset.

MaterialBarracuda48 wrote: ↑Thu Jul 16, 2026 10:50 am The v1 site and v2 (new) site use the same login details.
You may have to follow the "forgot password" choice for a reset.

Mmm, forgot password doesn't work either. It says its sent an email to my registered address and nothing turns up. Tried 3 times.

Can you still login to v2 website?
If yes, can you extract password from browser?

Yes and how. If you mean see the password in case I've forgot it then I've already done that and my v2 password is the one I'm typing in. I've even tried a different browser. Just about to try a different device.

For the V1 login you need to be using your username (not your email), V2 allows both but V1 only allows your username to be used.

Dave Foster wrote: ↑Thu Jul 16, 2026 12:14 pm For the V1 login you need to be using your username (not your email), V2 allows both but V1 only allows your username to be used.

Good shout, I've only ever used my username.

Dave Foster wrote: ↑Thu Jul 16, 2026 12:14 pm For the V1 login you need to be using your username (not your email), V2 allows both but V1 only allows your username to be used.

Thanks, this worked. I'll have a play with the app now.

FYI, system installed at the end of Feb '25
6.16kWp worth of panels.

I 'made' £1,179.09 in 10 months, if I add in Jan & Feb '26, that's another £64.33 for a 'full' year.
2025 Was above average year from all accounts.

I calculate my ROI from export and assign any self-use PV with xx p kWh.


You have 8.55kWp worth of panels, so I think you should do just fine.
Best of luck finding values from Energy Stats.

To display inverter consumption go to Settings, Inverter, Display Options.
Consumption will then appear on the Stats page.
Hope it's useful.
At the end of the day though, although it's interesting to know, I suspect this is an academic exercise. The inverter has got to do it's job and it's got to consume the power it needs to do it.

daveg wrote: ↑Thu Jul 16, 2026 5:24 pm At the end of the day though, although it's interesting to know, I suspect this is an academic exercise. The inverter has got to do it's job and it's got to consume the power it needs to do it.

I agree. My gripe though is with whether it is taken into account when the installers provide your ROI because it is such a large amount.
My figures were based on me telling them I used 8-10KW per day so presumably they took the middle figure of 9KW.
With the the inverter usage I'm using nearly 3KW more than that (4 in reality but I overstated my usage which should give me increased benefit). This number should be deducted from the generation estimation as it is generated power that is not freely available to me to benefit from.

Here are my readings for the past few days comparing Energy stats app to ESS app.

En Stats En Stats ESS
Inverter consumption consumption Difference
16-Jul 4.7 5.6 10.8 0.5
15-Jul 4.6 6.3 10.7 -0.2
14-Jul 3.8 6.4 9.8 -0.4
13-Jul 3.2 6 9.8 0.6
12-Jul 5.2 7.2 12.6 0.2
11-Jul 5.3 7.5 13.1 0.3

It immediately raises a few questions which hopefully someone can answer.

1. Why is there a swing in the difference between the 2 apps totals i.e. sometimes ES total is higher and sometimes ESS is higher?
2.Why is there such a difference in inverter usage per day (3.2KW-5.3). What aspects of the cycle, generation, charging, discharging etc. are the biggest drain?
3. Why would the 2 apps not have the same figures? They will be using the same data.

I'm pretty sure that ES must be overestimating my inverter usage and underestimating my consumption primarily because everyday, the consumption has been below my 7.77KW pre install average and I can think of no logical reason for that.

TIA

ROI calculations consist of two parts.
1. Export payments
2. Self-use

It's all baked in, doesn't matter if your system uses 0.5kWh a day to power itself, or 3.5kWh... it's all under the self-use umbrella.

I made £1200 in a year with less kWp, and I was not trying to min/max. You should make more than that, unless you have some bad shading issues later in the year?

If you open your FoxCloud2.0 App, and click daily production -> Month -> Select 2026-06 and take a screenshot I can compare your saving vs. mine.