Hi there,
I have had a FOX ESS Installation (8 panels, 1 inverter, 3 batteries) now for 1.5 years. Really happy with it. I have been trying out the V2.0 of the App and appreciate that they are really trying to improve the interface for customers. But, I find the stats totally confusing and the data does not seem to add up. Wondering whether the charging/discharging of the batteries
is not taken into account properly. I always charge my batteries from solar only. I don‘t discharge the batteries to the grid.
Data showing in the Production and Consumption graph is not consistent. Currently in the production graph I see a Self consumption of 869.9kWh/year. In the Consumption graph I see Self-sufficiency of 781.2kWh, so 88.7 kWh less. Shouldn’t these figures be the same?
The Production is given as 2.0MWh, whereas in the older app version Total Yield is 1964 kWh.. Just rounding errors?!
Also looking as bar charts below, in the yearly bar chart the stats for January show 0 kWh Solar Produced, but 25.8kWh exported to the grid and Load consumed is 182.3kWh versus a grid import of 91.8kWh?!
I am trying to work out as accurate possible, how much money I saved by NOT importing from the grid.. Currently I assume that the data given in Consumption/Self-sufficience might be the more accurate one.
Have looked at. various topics here, but did not find an explanation.
Any ideas?
Thanks.
Confused by data in V2.0
Self consumption in the top circle is everything you've used from the solar including battery charging. Basically it's solar generation minus feed in.
The bottom is your house consumption and shows what percentage is from the grid.
The solar PV generation isn't shown for January as this was a feature added as v2.0 developed. Mine starts November last year but shows nothing before then like yours.
The yield figure on the old app can't be compared as that included everything that went through the inverter including battery usage.
Hope this helps.
The bottom is your house consumption and shows what percentage is from the grid.
The solar PV generation isn't shown for January as this was a feature added as v2.0 developed. Mine starts November last year but shows nothing before then like yours.
The yield figure on the old app can't be compared as that included everything that went through the inverter including battery usage.
Hope this helps.
Thanks for your swift answer. You confirmed my interpretation of the data. That still does not explain to me the discrepancy of 88.7kWh. My home consumption minus import from grid should be everything I use either directly from solar or from the batteries. Are these 88.7kwH a loss that occurs from charging/discharging batteries or the inverter?
With respect to the new feature ‚Solar produced‘; ok, they introduced a new interpretation of the data, exported from the data logger. I assume that the raw data is stored in the cloud, the data format is unchanged (at least I didn’t have any firmware upgrades). So I cannot see why the new version cannot interpret the old data in the same way.
A guide explaining the stats would be useful. Is someone from FoxESS monitoring this forum?
With respect to the new feature ‚Solar produced‘; ok, they introduced a new interpretation of the data, exported from the data logger. I assume that the raw data is stored in the cloud, the data format is unchanged (at least I didn’t have any firmware upgrades). So I cannot see why the new version cannot interpret the old data in the same way.
A guide explaining the stats would be useful. Is someone from FoxESS monitoring this forum?
Yes, pretty much that. Whenever DC to AC conversion takes place (or AC to DC when charging batteries from the grid) there will be losses (approx. 10% I've found, i.e charging the batteries from the grid it takes about 8.8kWh to get 8.0kWh in). There's also the power used to keep the hybrid inverter "alive" as well as the fact that the cloud only updates every 5 minutes so figures can be slightly "off" - yesterday for example the cloud says we exported 27.9kWh, but in reality it was 28.6kWh.
With regards to the solar figures only going so far back. I'm not entirely sure whether these figures are from the cloud or from the inverter itself. The reason I say this is that my figures go back to 1st November which was the exact date my inverter firmware was last updated. This would suggest the figures are from the inverter itself, as a firmware change would not affect the data already uploaded to the cloud. I used to download the data and calculate this manually before this feature arrived and the cloud figures did not exactly tally with the inverter front panel. The front panel figure however is always the same as the figure now in the v2.0 app.
With regards to the solar figures only going so far back. I'm not entirely sure whether these figures are from the cloud or from the inverter itself. The reason I say this is that my figures go back to 1st November which was the exact date my inverter firmware was last updated. This would suggest the figures are from the inverter itself, as a firmware change would not affect the data already uploaded to the cloud. I used to download the data and calculate this manually before this feature arrived and the cloud figures did not exactly tally with the inverter front panel. The front panel figure however is always the same as the figure now in the v2.0 app.
I am still confused by this. Here was my data from the first 10 days of January.
The production graph makes sense: I’ve produced 306.1 kWh of which 99% was for self-consumption (still waiting on my bidirectional meter so I can export to the grid).
The consumption graph doesn’t make any sense to me. I think it’s saying that my total energy consumption from my solar system and battery is 250.4 kWh. But this would mean that I am lost 56ish kWH or more than 20%. This seems like a pretty significant loss.
Is it because they installed a 30kw inverter that’s just a power hog even though it was only supposed to be 12kw? If so, is there a way for me to change the settings to improve the efficiency of the inverter?
The consumption graph doesn’t make any sense to me. I think it’s saying that my total energy consumption from my solar system and battery is 250.4 kWh. But this would mean that I am lost 56ish kWH or more than 20%. This seems like a pretty significant loss.
Is it because they installed a 30kw inverter that’s just a power hog even though it was only supposed to be 12kw? If so, is there a way for me to change the settings to improve the efficiency of the inverter?
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Dave Foster
- Posts: 1557
- Joined: Thu Oct 13, 2022 7:21 pm
Your solar Production was 306.1kWh (A)srooke wrote: Sat Jan 11, 2025 9:38 am I am still confused by this. Here was my data from the first 10 days of January.
IMG_9736.jpeg
The production graph makes sense: I’ve produced 306.1 kWh of which 99% was for self-consumption (still waiting on my bidirectional meter so I can export to the grid).
The consumption graph doesn’t make any sense to me. I think it’s saying that my total energy consumption from my solar system and battery is 250.4 kWh. But this would mean that I am lost 56ish kWH or more than 20%. This seems like a pretty significant loss.
Is it because they installed a 30kw inverter that’s just a power hog even though it was only supposed to be 12kw? If so, is there a way for me to change the settings to improve the efficiency of the inverter?
You Exported 4.2kWh (B)
So your Self-Consumption is (A-B)=301.9kWh (C)
Your % Self-Consumption is the ratio between (C / A) = 99%
Your Consumption was 355.9kWh (D)
You Purchased 105.5kWh from grid (E)
Your Self-sufficiency is (D-E)=250.4 (F)
Your % self sufficiency is the ratio between (F / D) = 70%
Your system efficiency (Input/Output) is:
Input = Production (A) + Purchase (E) i.e. 306.1 + 105.5 = 411.6kWh
Output = Export (B) + Consumption (D) i.e. 4.2 + 355.9 = 360.1kWh
Your system losses is the difference between Input and Output (51.5kWh) and that is 12.5% of the Input (51.5/411.6) ~ 87.5% efficient.
Measured over a small period there will likely be differences in the amount of energy that went in / out of the batteries i.e. if the battery SoC was different at the start and end of the period - so best to wait until the end of the month to get a more accurate reading.
There are losses at multiple stages i.e. in the MPPT's, the DC to AC conversion from solar/batteries to feed the house, AC to DC to charge the batteries and in the chemical process of storing and recovering energy (Fox say approx 95% round trip efficiency) and of course in keeping your inverter and BMS running.
All in all 87.5% isn't too bad for an inverter of that size at this time of year, I have a 6kW inverter and my efficiency so far this month is 90.5%