Metre reading miss match

[Rusty_Nuts]

As I have a high quality digital inverter I have the ability to view all output and feed in and production values of my solar system.

However these figures don't match the smart metre and my bills are way too excessive.

How can I get my metre inspected for correct installation and calibration

[MulgaBill]

Hi Neil,

Once again thanks for taking the time to explain the mysteries of the universe albeit only the Solar Energy segment. 

I have downloaded AGL's figures and analysed one month  (March 2020) of data. The figures matched my usage displayed online. No surprises there! 

Clearly,  AGL only use the data supplied by my smart meter to account for my Consumption and Export data etc.

I just can't get my head around the two sets of Export numbers matching whereas the two sets of Import numbers don't.

For what its worth will forward my data files to you by separate email, just for your confirmation that I'm not going mad!

In the mean time, will ponder the wonders of the Solar System and our position within the universe, which is far easier to understand than AGL's Solar figures!!!

Cheers Mulga Bill

[NeilC]

MulgaBill,

Thanks for the data you supplied to me.

After your supplied file caused my program to crash I went back to using a spread sheet and converted the data manually and did find that your April readings did not match the amount that AGL said they supplied you.

BUT, the AGL readings did equate to 245.357Kw as you informed me and your Report Supplied from your SolarEdge device showed 174.515.

AGL Import	SE Import	Difference
245.357	174.515	70.842

The difference being 70.842Kw less than AGL indicated.

I emailed you and asked if the AGL file, you supplied, had been modified but you did not reply.

Investigated this, late this morning, and found that you had modified the file (you removed your account number).  Simply added back the missing column (with a made up number) and ran a report using my programmes to produce an hourly report for each day of April.

Now what I found was:

UNUSUALLY HIGH FIGURES

00:00>01:00	01:00>02:00	23:00>24:00	Total
39.238	22.894	29.842	91.974

Analysis of close hours showed:

                         Expected Figures

02:00>03:00	03:00>04:00	22:00>23:00	Total
5.893	5.414	9.863	21.17

These figures are the TOTALS for the hours in April this year.

So lets see what happens if we NORMALISE these figures.

                     Normalise - High figures

91.974

MINUS

21.17

= 70.804

So what happens at your house each night between 23:00 and 02:00 hours. A few things come to mind a timer that turns on to heat your hot water, a swimming pool pump etc etc.

Now the funny thing is that this 70.804 figure near exactly matches your 70.842  figure that you  say you are being overcharged for.

Now your system has an inductive coupling that goes around your wiring to read current flows. I would say that whatever drives the device(s) that draw this 70 odd KW from your system is UPSTREAM of your coupler but before the meter, hence your meter sees it but your add on meter does not.

A review of the data you sent to me shows that the spike occurred over more hours in January and February.

Please investigate this and let us know what transcribes.

Cheers

Neil

[MulgaBill]

Hi Neil,

Have reviewed your response and can advise as follows.

Call me paranoid, but I did delete my Account Number as I could not see that it served any purpose in your calculations. Clearly it did mess with your program file.

Confirm the hot water system does come on each night plus on occasion we set the dishwasher to come on late at night. Other than that, there are no other items that consume high amounts of power.

Admittedly the whole basis of my question was based on just 1 month of readings (April). And the fact that there was a difference raised the obvious question: Why?

With regards to spikes occurring in Jan and Feb, I cannot explain without further investigation.

As for the possibility that a device upstream of my coupler is drawing 70 odd KW from my system, I can only guess. Surely my modem which is located downstream would not be drawing this amount?

Will need to investigate this further with the installer to see if they can shed any light on your findings.

In the interim, will continue to monitor the figures to see if the discrepancy continues.

Thanks for your detailed analysis and assistance with my request.

Mulga

[NeilC]

Thanks for the reply, I suggest that you pay for someone to fix your issue.

I have wasted too much time on this.

[Cory]

I’m having same issues I think the difference is coming from hot water system as it kicks in solar edge app shows shows I’m using solar to power it but in fact it’s coming from the grid and Saying I’m not exporting power when it really is exporting at the same time when hot water is importing.  I have a video of old meters one going backwards EG feed in and hot water meter going forward but app says I’m importing power from grid on solar app. 

[NeilC]

Cory,

I am not  an expert on Solar Edge and in fact have never seen one in real life.

Now what I can tell you is that your Supplied Electricity Meter readings are what you will be charged on. This information you can get from the MyUsage file download.

Solar Edge installs own monitoring devices onto the existing house wiring circuit and if not installed correctly will not properly capture the correct information.

In your house circuit the power comes from the Street Supply (Grid) into your meter, (This meter reads ALL incoming and outgoing power), if you have a meter that allows you to have a Controlled load (like a hot water system), the meter itself switches on the power at the set times to the controlled load section of the meter.

The controlled load circuit must be a separate circuit to your normal house wiring and the power used by this meter is read independently from any other meter. (So you don't get charged twice).

So with a single controlled load meter (you can have two or more on some meters) you will have two active wires coming from your Power Meter.

The main circuit wire is of a larger current capacity (63amps or more) than the Controlled load wire (Normally about 30amp capacity).

With Solar Edge you must have a monitoring device on both of these lines.

Now in saying this I assume that you have a  meter equipped with a controlled load meter.

Without physically seeing your wiring it is impossible to see what is occurring.

For instance you have not stated if your hot water system is on a controlled load or not.

I don't know how your Solar Edge App is saying the hot water service is using solar. If your hot water is not using a controlled load circuit then it will simply take it's power as required from the main house circuit and you will be charged peak rates.

If you have a top of the range Solar Edge install, then you will have individual monitoring devices on separate circuits after your main circuit switch board, if you do not have this then it is possible that your app is not correctly setup.

In a house with Solar Installed:

1.  The solar panels are connected via one or more Direct Current feeds that the Inverter.

2. The inverter converts DC into Alternating Current at approximately 240 Volts.

3. This current is fed (via a separate Circuit Breaker) into the main circuit bus bar.

4. The house wiring will then use as much of the Solar Generate AC as it can.

5. Any EXCESS Solar power is then EXPORTED (Via your meter) into the Main Street (Grid) Circuit.

On a Single Phase Meter it is not possible to IMPORT and EXPORT power at the same time. If the amount you are generating is equal to the amount you are using then you are not using any power from the Main Street Circuit nor exporting any power back to the Street Circuit (Grid).

Otherwise any excess is Exported to the Street Circuit or you are Importing power from the Main street circuit.

Time	08:00	08:30	09:00	09:30	10:00	10:30	11:00	11:30	12:00	12:30	13:00	13:30	14:00
Solar	0	0.111	0.235	0.906	1.335	0.907	0.794	0.978	0.840	0.215	0.856	1.148	0.525
Grid	0.066	0.005	0.062	0	0	0	0.002	0	0	0.065	0	0.004	0

Above you can see my actual meter data for yesterday (20 Aug) which I downloaded from my meter readings today (21 Aug). I have not shown all of the day but simply enough to give a comparison.

Readings are in kW (Kilo Watts), the time is shown in Black,  Solar Exported Grid is shown in Green and power used from the grid in RED.

Yesterday I exported 12.028 kW to the grid and imported 4.771 kW from the grid. I self consumed 4.97 kW.

Yesterday was a mainly overcast day with rain periods, also I have a heat pump hot water service that is set to heat between 10:00 and 19:00 each day. (This normally only takes 2.5 to 3.5 hours per day).

These figures are what I will be charged or profit from.

So yesterday cost me:

12.028	$        2.41
4.771	-$        1.96
Supply	-$        0.91
Total	-$        0.46

As you can see it cost $-0.46, but this is not true as I also got $0.99 benefit from the 4.97 kW that I self consumed.

All this from the meter readings that I will be charged for.

I would suggest that you contact Solar Edge and get them to investigate your installation.

If you want you can PM me and I will send you an Email Address that you can contact me on and send a copy of your usage file from AGL and I can analyse it for you.

You can of course look at Your Web Account then after logging in click on Usage or View Usage and see how you are going up to the last date shown on the bar graph. You can also pick on an individual day to see how you performed that day.

Now if you really want to test your system, on a day that is scheduled to be overcast, turn off your solar system altogether (before sunrise IE no solar for the whole day) and see what AGL says you use compared to what your Solar Edge says you use for the day.

Don't forget to turn the solar back on after Sunset...!

Right now I am producing 2200 Kw of Solar (at the inverter) and my Smart Meter says that I am putting 6 amps (or 1500 kW) to the grid. This I know, because I can use the hidden menu of my smart meter to read the instantaneous figures.

Hope this all helps, when you have a bunch of unknowns it is often difficult to know what the true facts are.

I know that after 18 months of having Solar installed that my Supplied Electricity Meter is accurate to  to what I can read on the meter.

(I did the opposite to what I have suggested to you and turned off all of my power for two hours and left my solar on, I could then check using the Web interface for my solar, the meter readings on my actual meter and the instantaneous readings on the hidden menu of my meter.)

Cheers

Neil

[JOEM]

Hi all,  I have a similar issue!  My import readings say I have used 6,612 Kwh hours, the same meters gives me historical usage and says I have used 5,839 Kwh and my solar pv and battery system says I have used 4103.2 Kwh.  Surely the import readings from my meter and the historical usage of my meter should match?  My issue is the increase in my bills since my solar and battery installation.  Previous year my total usage was 5,041.7 Kwh.  I do believe my meters are faulty but the check meter installed matched but the meter is still gicing two different outputs.  How is this possible?  Any help will be greatly appreciated!

[NeilC]

@JOEM,

I have read and re-read your post.

Cannot make any sense out of what you are trying to say.

Could you possibly re-post giving a better description.

Cheers Neil

[JOEM]

Apologies Neil,  I am struggling to understand it my self.

My energy bills where relatively cheap but I was renovating my home and wanted to future proof my property so I installed a 4kw Solar system with storage battery.  Since the installation my bills have went up dramatically!  I have some questions:

1. Should my import readings match the historical data of usage taken from my Smart 1 meter?

2. Should the usage recorded by Solis Inverter match the import readings from my meter?

As things stands my meter historical data matches closely to the information held on my inverter.

Any advice will be greatly appreciated!

Thanks

Joseph

[Hammond123]

We have been away from the 4th August 

I've not used any gas since, but my bill is increasing daily, at least 15.00 in the last day

Can you please explain why ?