Discrepancy between solar inverter power generation and the AGL app

[Kevinh99]

Hi There, I've been monitoring my 5kw Fronius inverter and the kwh produced each day. July 26th was an ok day and reading via the Fronius solarweb app was 18.0kwh produced. Yet on the AGL App for the same day it states just 7.22kwh sold to the grid and 21.01kwh bought from the grid. The figures don't stack up. 

Thanks

Kevin

[FMcBride]

Hi MrWill have you resolved your issue. I'm sure I have the same one but trying to explain it to AGL is doing my head in.

[NeilC]

Hope you find out.

Its been a year.

Why don't you ask the forum here

[DanHK]

I am seeing a similar kind of problem as what you have been observing.

My inverter is showing that I am generating about 28KWh per day. My normal usage of electricity for the whole day is usually between 8-10KWh. The AGL App is showing that I am only exporting on average about 6KWh of electricity back to the grid on a daily basis, whereas I am still using 8KWh daily (in the evening when there is peak usage). There is hardly anyone at home during the daytime. The discrepancy between what my inverter is generating and what the smart meter is telling me about electricity fed back to grid is huge. 

[NeilC]

@DanHK 

What does your usage say on the WEB interface.

Confused that you are saying consuming 8kW in the evening.

My usage yesterday was 4.612 kW I put back into the grid 21.573 kW I generated 28 kW.

Therefore I consumed 6.43 kW of my generation.

I have a heat pump hot-water service  that consumes about 3 kW of electricity when I am home alone. If my housemate is home then the hot water service consumes about 5 kW.

Now here are my readings for my current billing period.

Date	Peak	Exported	Solar Gen	Used	Meter	Solar
18-Apr-21	4.332	10.102	14.90	4.80	4125.711	16866.064
19-Apr-21	4.597	9.261	15.80	6.54	4130.308	16875.325
20-Apr-21	5.657	9.813	16.00	6.19	4135.965	16885.138
21-Apr-21	5.429	12.317	18.10	5.78	4141.394	16897.455
22-Apr-21	4.614	13.579	19.90	6.32	4146.008	16911.034
23-Apr-21	4.421	15.948	19.70	3.75	4150.429	16926.982
24-Apr-21	3.908	16.011	20.00	3.99	4154.337	16942.993
25-Apr-21	3.942	24.158	27.60	3.44	4158.279	16967.151
26-Apr-21	4.612	21.573	28.00	6.43	4162.891	16988.724

Now according to my inverter I generated 25 kW today.

I know my meter reading from last night (16988.724) my smart meter only allows me to read to ONE decimal point.

It is dark here and we are not generating solar.

I just went out and read my meter, it is 17009.4 for solar.

That means my output (that AGL will pay me for) is about 20.7 kW and that I consumed 4.3 kW of my generated power.

I will know my usage for today, at around 06:00 tomorrow when I check the website. (Not AGL's)

You have not shown any basis for your statements above.

I suggest that you take a reading from your meter at midnight your time, then after 24 hours have passed take another reading,

Subtract reading's two from reading's one and you have your consumption / export for a 24 hour period on the date that you took reading's two (note that the midnight reading's are really taken at 23:59).

Note that it may take up to 72 hours for the results to appear on the AGL Website.

I do not work for AGL and although a customer, I am only a member of this "Community".

However, I can tell you that if you are going to dispute your meter readings that it may cost you anywhere from $750 to $1000 if  you request a meter check and no fault is found.

Let me (and the "community") know how you go.

By the way my DATA is based on two years of FACTUAL information from AGL and my own meter readings.

As to what my inverter generates I can only see in the hidden menus of my Smart Meter the instantaneous  power being put into the grid, random checks show that I have no reason to dispute the amount of power that I am generating. (Again I have being doing this for the last two years).

Cheers Neil.

If you like my response please click the like button.

Anyway please let us all know your finding

[NeilC]

@DanHK 

As promised, it is 06:00 here in SA.

Here are my readings for the 27th April

Date	Peak	Exported	Solar Gen	Used	Meter	Solar
27-Apr-21	5.108	20.746	25.00	4.25	4167.999	17009.470

My "prediction" from above stated.

" I just went out and read my meter, it is 17009.4 for solar.

That means my output (that AGL will pay me for) is about 20.7 kW and that I consumed 4.3 kW of my generated power."

Now, what else I can tell you is that I used 4.59kW and exported 21.57kW on the 26th April according to the AGL Website.

Now according to my ElectUsed spreadsheet.

26-Apr-21

4.612

21.573

28.00

6.43

AGL states I used 4.59 and exported 21.57, the difference being -.12kW in my usage.

I don't know why this error appears but it is miniscule and worth about 4 cents.

If I look at my last bill (issued 18th April) the following usage figures were supplied.

Read       Start        End            kWh
Actual     14,677    16,856   2,179.295
Actual       3,636      4,121       485.958

My SpreadSheet states

Peak	Exported
486.031	2179.295

See my Solar is correct but there is .073 kW error.

Their bill was $164.29cr my calculated bill was $164.27cr.

Anyway lets see how you go with your meter reads.

Cheers Neil.

[Kim1]

Thank you Neil I have come across some discrepancies as well but very minor and most days pretty well spot on, if not have made up for the error in the next day, usually with Solar which does confuse me some what as their is no power produced after sundown. I surmise that maybe some readings are taken before sundown (well before sundown because very little is produced in the last hour of sunshine) I can only surmise once again that maybe the reading was taken early so a worker can go home early and therefore made up for in the reading the next day. Although I would assume readings are taken by computer I would also assume someone has to operate the computer. What ever the case maybe I am happy with results and being from Queensland more likely more sunshine ( unlike our friends in Melbourne). Not sure how Adelaide goes for sunshine but they seem to be having warmer days during summer than Brisbane.

Just wanted to say thank you for your dedication and reply.

[NeilC]

@Kim1 

AGL only knows two things about you.

1. The electricity that you consume each day from the GRID
2. The amount of power you return to the GRID.

Now they charge you for the power you consume and pay you for the power you put into the grid.

On behalf of your Electricity Supplier they collect the supply charge.

Now what your panels tell you outputted for the day, less the amount of power you used from the power you generated, is the amount that AGL will pay you for the day.

As you surmised, solar panels can only generate when there is enough sunlight.

If you have a SMART METER it transmits your usage every 30mins via a wireless link back to the SYSTEM. (No person involved).

If you don't have a Smart Meter then a Meter Reader comes round on the appointed day and manually reads your meter. (Typically once every 90 days or so)

That person enters the data into a HAND HELD device and and the data is then fed (either wirelessly or the internet) back to the SYSTEM.

Either way neither of us have control over this and unless we monitor our own meters are not aware of discrepancies.

Thanks for the positive feedback by the way.

Cheers Neil

[NGas]

Hi @DanHK ,
I am not sure if I understand your problem correctly, and most likely you will have resolved the issue by now anyway, but in case others read this post and have similar issues I'll add my 2 cents worth...
I have no real idea about solar, but your problem sounds like one I read about on another website. You can check it out to see if it helps, it is about incorrectly installed meters.
https://support.solarquotes.com.au/hc/en-us/articles/115001434733-My-SolarEdge-Monitoring-Doesn-t-Lo...
Hope it is helpful to at least someone...
🙂N

[David_AGL]

Hi @NGas , thanks for sharing that! Hopefully it will be helpful to someone.