Difference in smart meter and solar feed in reading

[Samuela]

Hi everyone,

I just wonder if anyone could give me some helps/advices on this? My smart meter says at 1pm, I have exported over 4kw of solar power to grid but AGL app says less than half (1.91kw) were. My smart meter also showed at that time I used only 300W at that also. I’m not sure what went wrong

 

 

 

[NeilC]

@Samuela 

You are getting confused over what meter you are reading.

A SOLAR INVERTER shows the total amount amount of power that your solar panels are generating.

The SMART METER is connected via your switchboard to the Electricity Grid.

Your retailer (AGL) has access to your meter readings.

The Smart Meter can only read INPUT from the GRID or EXPORT to the grid.

If you look at a particular time via your APPS then your EXPORT to the grid is the power generated by Solar MINUS the power consumed by your house.

Your meter can only do two things (for a single phase supply) and that is either give an export figure or an import figure.

You get charged for IMPORT and get paid for EXPORT.

Here is some figures from my system for the last week.

Date	Peak	Exported	Solar Gen	Used	Meter	Solar
15/09/2021	2.942	28.206	32.1	3.894	4845.029	18882.63
16/09/2021	3.425	31.342	34.9	3.558	4848.454	18913.97
17/09/2021	4.513	28.209	33.2	4.991	4852.967	18942.18
18/09/2021	5.759	20.577	25.2	4.623	4858.726	18962.75
19/09/2021	3.917	27.604	33.9	6.296	4862.643	18990.36
20/09/2021	4.401	19.691	24.4	4.709	4867.044	19010.05
21/09/2021	3.403	19.162	24.1	4.938	4870.447	19029.21

So for yesterday:

I will get charged for 3.403 kWh.

Will get paid for 19.162 kWh.

Self consumed 4.938 kWh of my generated power.

You can also see that I know my meter readings for Midnight on that date,

I have a heat pump hot-water system that consumes about 3 kWh of my Solar (thus my hot-water is free).

Below is part of my data for yesterday 21st Sept

	Date	15:00	15:30	16:00	16:30	17:00	17:30	18:00
Imported	20210921	0	0	0	0	0	0	0.017
Exported	20210921	0.72	0.792	0.418	0.459	0.517	0.526	0.138

I actually did not pay for any usage from 7:30am till 5:30pm and you can see at 6pm I paid for .017kWh and also got paid for .138kWh.

Now for my current billing period :

Cost Per Day	-$       0.7225
	Supply Cost per Day	$            0.8910
	Peak Usage per Day	$            1.7597
	Off Peak usage per Day	$                      -
	Solar income per day	$            3.3732

Basically though unless you have the ability to create  your data into one reliable source you should just rely on the AGL to show you your usage via the app.

Cheers

Neil

If this has resolved your issue please resolve this and also give a like.

Remember the answers given by most people on these pages are given by members of the public (AGL staff are identified)

[GregAGL]

Neil

GregAGL just checking this example against.our PM discussion.

• You state that the smart meter can do two things read export to grid from solar and input from the grid. My confusion occurs at 1800 when both things occur at the same time. Surely if you are using .017 and producing .138 at the same time, the meter should.balance out and just credit you with the balance. OR charge the balance!
• This is where I and AGL are confused. My bill has many of these input and export values at the same time. My Enphase app shows I am producing excess for the entire time( ie no clouds etc)
• Please help with an explanation
• Cheers
• Greg 

[NeilC]

@GregAGL 

Greg,

You are talking about a HALF HOUR PERIOD.

Your HOME will consume energy from your solar system first and any extra will be fed from the grid.

If you are using 3kW of power and generating 3kW of power your usage will be 0 and your export will be 0, say the shines a little harder and you produce 4kW  you will export 1kW and not draw any thing from the GRID.

Next those nasty clouds come back and you are now only producing 2kW, you will draw (import) power from the grid.

This may occur many times during the half hour. At the end of the half hour the meter sends out what you consumed (cumulatively) in the half hour and what you exported (cumulatively).

These figures may be small amounts or large amounts but they are accurate.

If you really doubt that the meter is incorrect, you can ask for the meter to be tested.

In this case a big truck and a couple of guys will come around your place, they will then place loads onto you house and read load figures on the down side of your meter, they will also check the output from your solar system on the up meter side of the meter itself. (Very simplified explanation here)

Once completed they will present you with a bill of say $600 to $900, now if your meter is faulty they will replace it and you won't have to pay other wise you have to pay up.

If you don't pay they will disconnect you from the Grid.

I will say again you are not exporting and importing at EXACTLY the same time.

Just so you can see what 5m readings are like

17/01/2023	6:35	06:40	06:45	06:50	06:55	07:00	Total
Import	0.012	0.003	0.001	0.001	0.000	0.000	0.017
Export	0.005	0.001	0.003	0.007	0.008	0.010	0.034

You can see the accuracy of the meters here, the amounts are minuscule and the 30min readings from AGL match the totals above.