Daily calculations for feedin tariff

[Hawthorn]

Hi,

I recently changed my plan to Solar Savers (which gives me 10c/kWh for the first 10kWh, and 4c/kWh above that).  I noticed that calculations for the daily feedin tariff is somewhat unusual, best by following example:

Solar Electricity Sold to Grid =               13.07kWh

By my calculation, this should give me   $1.12

However, the AGL App displays              $0.84

The descrepancy is                                 $0.28

Not much (but this is true for most days)., I just couldn't understand how AGL calculations work?

Anyone has similar experience?

[Lester]

Are your figures coming from your solar system app, or from the AGL info on your account ?

[Hawthorn]

Hi Lester, the "kWh" figures are from the AGL App (which BTW, agree with my solar system app). The reason for my post regarding the dialy feed-in tariff calculations is purely based on curiosity as to how AGL do their daily calculations.

When I was on Value Saver plan (with a straightforward 4c/kWh for feed-in tariff regardless), the daily calculations  of the feed-in tariff were spot on. Now with the new plan (with tiered tariffs), it seems to be doing something rather random, which prompted me to query the calcualtions (used to be a math teacher -:).

[Lester]

YEs, it's odd the figures don't add up right, hopefully an aAGL rep will be in touch here soon and get your info to check how they come up with that.

I'd collate as many of those discrepancies as you find and have ready to present them, a spreadsheet should be doable to formulate some totals.

It might only be $0.28 or such, but it adds up over time, and should be correctly billed to you.

[megan_AGL]

Hi Hawthorn,

Thank you for bringing this matter to our attention.

We will send you a private message to get some more details from you.

Kind regards,

Megan

[NeilC]

@Hawthorn @Lester @megan_AGL 

Hi all, you need to understand that this is not your actual usage but really an approximation of your usage.

For instance the 13.07 kWh of feed in could be 13.065 or 13.075.

The other figure you are neglecting is the electricity used figure, which again is just an approximation.

Then of course you are missing the fact that they have not included your supply charge.

Now looking at my data for solar it says I have $7.11 for my 90.09 kWh of solar feed in for the first 4 days of this billing period. Yet if I add up each day the amount is only $6.98, my real feed-in figures are only $7.01.

My exact figures for the first four days of my billing period is that I had 90.087 kWh of feed-in for these four days.

Day 1	Day 2	Day 3	Day 4	Total
18.675	19.463	21.657	30.292	90.087
$1.52	$1.57	$1.70	$2.21	$7.01

Now the app / web says I bought $6.99 or 15.22kWh of electricity but in actual fact I only used 15.024 kWh and would have paid $6.26 (no GST) or $6.89 (with GST).

As I said it is not an an exact figure AGL quotes, but a fairly close approximation.

My page says +$0.13 in credit but they are way off I am ONLY +$0.12 in credit, don't forget though I have to add my supply charge to that $4.22 (with GST) so I am actually $4.10 in debit to AGL on my 4th day into this bill.

Well I am happy with their NET USAGE cost of +$0.13 ...  AGL was wrong by -$0.01

So my answer to you about "Anyone has similar experience?" my answer is yes, but I have supplied your answer  with FACTS.

[Hawthorn]

Thanks Neil for taking time to provide your view of things. The point of my post is to understand the calculation that AGL use (not to complaint, as I have been over-paid as well as under-paid as per the below table). The daily feed-in tariff may be an "estimate" (until such a time that an invoice is generated) but mathematically speaking, the numbers are all over the place (non-consistent).

	AGL App Data Solar Electricity    Sold To Grid (kWh)	AGL App  Data Solar Electricity Sold To Grid ($)	My Calculations Based on Solar Savers Plan First 10 kWH: 10c/kWh Subsequent: 4c/kWh	Descrepancy
Date	(kWh)	$	$	$
11/09/2024	19.89	1.25	1.40	-0.15	Underpaid
12/09/2024	32.51	1.95	1.90	0.05	Overpaid
13/09/2024	37.71	2.39	2.11	0.28	Overpaid
14/09/2024	13.07	0.84	1.12	-0.28	Underpaid
15/09/2024	20.73	1.34	1.43	-0.09	Underpaid
16/09/2024	21.46	1.40	1.46	-0.06	Underpaid
17/09/2024	22.13	1.45	1.49	-0.04	Underpaid
18/09/2024	19.70	1.35	1.39	-0.04	Underpaid
19/09/2024	2.65	0.19	0.27	-0.08	Underpaid
20/09/2024	0.57	0.04	0.06	-0.02	Underpaid
21/09/2024	6.37	0.48	0.64	-0.16	Underpaid
22/09/2024	10.23	0.76	1.01	-0.25	Underpaid
23/09/2024	19.76	1.51	1.39	0.12	Over Paid
24/09/2024	2.26	0.18	0.23	-0.05	Underpaid
25/09/2024	8.22	0.62	0.82	-0.20	Underpaid
26/09/2024	30.87	2.30	1.83	0.47	Overpaid
27/09/2024	27.22	2.04	1.69	0.35	Overpaid
28/09/2024	13.26	0.98	1.13	-0.15	Underpaid
29/09/2024	27.76	2.05	1.71	0.34	Overpaid
30/09/2024	18.38	1.36	1.34	0.02	Overpaid
1/10/2024	16.18	1.18	1.25	-0.07	Underpaid
2/10/2024	30.58	2.23	1.82	0.41	OvepPaid
3/10/2024	22.27	1.62	1.49	0.13	Overpaid

[Deepesh_AGL]

Hi Hawthorn, I can see the logic behind your calculation and would like to look further into this. I will send you a private message shortly to discuss further. Cheers, Deepesh

[Old_Mate]

I read some where ! That they work the daly  exports under the limit and above the limit by adding each daily export and dividing the sum by the  number of days , thus  working out a daily average , and then applying the limit and the excess and  then multiplying the result  by the number of days in that month.