Drawing from grid and exporting at same time

[quinny]

Can anybody tell me why I show that I am drawing from the grid AND exporting at the same time in the middle of the day. Was changed over to NET metering a couple of months ago.

Seems like a way for AGL to make money, Charge for power at a high cost and give me a lttle money for the export at the same time, when I should be using all my solar and not drawing from the grid.

Please explain???

Or would this just be a technical difficulty the AGL have every day with everything?

[GregAGL]

Thanks Neil
This still does not explain while in a half hour period producing in excess
of 6kw all the time and only using a maximim of 4 kW in the same period
through my appliances, I get a feed in amount and a cost from grid at the
same time.
Is it possible that something in my house is drawing more than the 6kW
momentarily and therefore needs draw from the grid for the extra. This is
strange as I have alive feed on my panels and have been watching production
vs usage and I donot see any spikes.

Is the full 6kW produced available to me or is it like a battery where it
can only release a.certain amount over time. Hence the need for more
batteries to meet demand.
Possibly when an electric motor starts up it draws more than my panels can
provide and hence draws from the grid at the same time. How would I test
this? How much more solar would I need to prevent this happening while the
sun is shining.
Off course when cloudy or intermittent Sun this would occur and I can see
that in my live feed.

Just looking for a plausible explanation why my solar is not meeting my
demand when my demand is well below production levels. Any explanation
appreciated.
I do find it interesting when I questioned AGL regarding this issue they
offered me $150 compensation to cover any shortfalls. Is there a problem or
not?

[quinny]

Check with whom ever installed your solar and make sure they have connected to all circuits, maybe they could not connect to all of them and so one is pulling from the grid whilst the others are covered by the solar.

eg. power and lights circuits hooked to solar but maybe shed is not.

this turned out to be the issue I had, no room to connect to all of house so they connected just to shed circuit with pool pumps as they used the most power 

[GregAGL]

Some days my solar covers everything. Similar sunny day( ie same production
/ usage curve where solar exceeds usage) and I get both feed in and usage
in same half hour period. Same usage pattern each day
When cloudy the production curve drops and.I naturally draw from grid
Since some days solar covers usage, I donot think it is a missing circuit
connection.
Still scratching my head

[GREG-S]

Did your installer work that out for you? Or did you get an independent sparky to check it?

[NeilC]

@quinny 

Smart Meters are smart.

For instance if you have excess solar generation,it will flow through the Export side of the meter, if you do not have enough generation, power from the grid flows through the import side of the meter.

When installing Solar the only connection you need to make is to connect the Solar output to the main circuit board.

The only reason they connected to the shed was that there was no room to add another circuit into the board and used the shed circuit to get the power BACK to the main board. The shed should have been wired with heavier wiring anyway.

So in your case the Solar Circuit Breaker will be located in your Shed and the Main Solar AC Solar Switch on the wall next to the inverter.

In the Main Supply Board (Meter Box), there should be an tag indicating that Solar Circuit Breaker is located in the Shed Sub Board and that the Solar AC Switch located next to the inverter.

The instruction for your Solar should indicate that to isolate the solar you need to :

1.  Turn off the Main AC Supply Switch.
2. Turn off the DC Supply Switches

To turn back on, reverse the the process, DC On, Main AC back on.

Once again I will iterate that it is possible to EXPORT and IMPORT, you can never do this at the SAME time (your time is in milliseconds) but remember your INTERVAL METER (Smart Switch) supplies readings at intervals (30, 15 or 5 min are common).

In 30 min intervals you will see it more often than 15 or 5, but it will occur.

You can see above when I was exporting / exporting on the 29th July 2023.

The 5min interval readings are supplied to me by SA Power Networks

The 30min readings are supplied from My Account at AGL.

I deliberately picked this day as it was clearly overcast as I generally don't import any power from 08:00 till 17:00 on most days, but then we only consume round 5kWh a day any way. The higher you usage the more chance you will get of using all of your solar.

Above is Screen Report for running my program to convert the AGL data into a NEM 12 format file. My data from SA Power Networks is supplied in NEM 12 format.

Note that I also only use meter readings based on my consumption for the Bill, I gave up actually reading my meter, a long time ago as it has been reset many times.

You will also need to note that the New Look AGL Bill DOES NOT CONTAIN meter readings, ONLY YOUR CONSUMPTION for the billing period.

Above is the results so far for my current billing cycle (in my Plan Schedule), you can see why power is cheaper in Shoulder Rate... My HIGH usage (3%) of shoulder power is because I heat my hot water during this period...

And here is my projected bill, I pay $22.50 every fortnight, so I don't get billshock.

[Lulu1]

How can you have your hot water heated at Shoulder time? Mine is on control load which heat at night when my solar is not work.

[NeilC]

@Lulu1 

The answer is simple, I have a heat pump Hot Water Service.

I simply set the time for it to turn on when ever I want, in my case its from 10:30 and 17:00 even though most days it has heated the water to 66deg C by 13:30. (Less in Summer as the inlet water temperature is warmer)

You may be able to obtain a FREE HEAT PUMP for your place.

Also, there are three controlled load Tariffs that are  available now, a solar sponge Tariff is available.

[Electricpower]

I also have that situation where import / export at the same time

My understanding is that you use electricity constantly so the 30 min cycle is just a measurement

example 

let’s say

8 to 8:10 am everybody is up having breakfast using the bathroom, etc

you produce 0.05 kWh , but use 0.07 ( you import 0.02) 

8:10/20 am you add the dishwasher

produce 0.08 use 0.12 (import 0.04)

820 to 830 nobody home only fridge on produce 0.1 use 0.03 ( export 0.07)

total for 30 min (8 to 830)

produce 0.23

usage 0.22

import 0.06

export 0.07

if you read the 30 min report you can say why if I am producing more than what I use I am still importing ….?!!!!!

[Electricpower]

I also have that situation where import / export at the same time

My understanding is that you use electricity constantly so the 30 min cycle is just a measurement

example 

let’s say

8 to 8:10 am everybody is up having breakfast using the bathroom, etc

you produce 0.05 kWh , but use 0.07 ( you import 0.02) 

8:10/20 am you add the dishwasher

produce 0.08 use 0.12 (import 0.04)

820 to 830 nobody home only fridge on produce 0.1 use 0.03 ( export 0.07)

total for 30 min (8 to 830)

produce 0.23

usage 0.22

import 0.06

export 0.07

if you read the 30 min report you can say why if I am producing more than what I use I am still importing ….?!!!!!

[NeilC]

@Electricpower,

I will make this really easy for you.

AGL shows you your usage at thirty min intervals, however you meter is more than likely to be configured for 5 minute intervals (this way they can get more from you if you are stupid enough to have demand rate).

Now, when you export power there is a meter for that, and when you consume power there is a meter for that.

So every interval it reports your consumption and your export.

When you look at your bill you are charged for your consumption and get a redemption for your export.

Now if your solar panels are producing 500W and you are using 500W there is no export and no consumption, as you are self consuming your generation.

If you are on a time of use tariff, then the time stamp of the INTERVAL data is then used to calculate your costs.

Now I will show you my data for my current billing period so far.

Reporting from 20240929 for 13 Days

DATE       TYPE    NMI  Days Last Data Meter Read    Day Avg
20241011 Solar     B1    13     31.838     322.497          24.807
20241011 General E1    13       2.118       43.223            3.325

Below is my daily usage

Date	Peak	Shoulder	Off Peak	Exported
29-Sep	2.621	0.008	1.185	18.675
30-Sep	2.348	0.288	1.343	19.463
1-Oct	2.236	0.000	1.236	21.657
2-Oct	2.523	0.000	1.332	30.292
3-Oct	2.549	0.000	1.201	21.544
4-Oct	1.87	0.389	1.366	19.216
5-Oct	2.054	0.000	1.232	17.288
6-Oct	1.822	0.000	0.791	20.048
7-Oct	2.804	0.000	0.989	27.543
8-Oct	1.537	0.000	1.068	30.828
9-Oct	1.989	0.000	1.256	32.899
10-Oct	1.876	0.000	1.192	31.206
11-Oct	0.973	0.000	1.145	31.838
Total	27.202	0.685	15.336	322.497

So you can now see my daily usage for the first 13 days of my current billing period (quarterly), I could go further and show you my exact billing for this period but I won't. I could also show you the prediction of this bill including all cost's.

But be assured, when I get my bill it will be within 1 cent of what I know what my bill should be. (This is due to rounding as calculated by AGL and the rounding that I use in my Excel spread sheet).

Now you also need to under stand that you are charged in kWh (kilo Watt hours) and that usage is in kilo watts, meters are configured normally to 3 decimal points. (Which is what you see on your bill)

Note that I am using the AGL download file my data is to 3 decimal points.

My inverter however, only shows data to 2 decimal points, my spreadsheet takes my daily generation and can therefore can show my Generation minus my Exported figure which is approximate because of the 2 decimal point minus three decimal points.

So the answer to your question

"if you read the 30 min report, you can say why if I am producing more than what I use I am still importing ….?!!!!!"

I have explained this but.

YOU HAVE CONSUMED THE DIFFERENCE WITHIN THE HOUSE.....