Demand Tariff & Spike in usage

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I have come here in the hope of finding some answers to my questions as AGL Chat & Complaints are absolutely hopeless.

My first issue is that while we were away over Christmas for 5 days I can see a spike in my electricity usage by 300% for one half hour period per day. Following is an example of 2 days

21 December - 7:30am - 7:59am (Usage 0.121kW)
22 December - 5:30am - 5:59am (Usage 0.128kW)
Other than these half hour spikes (once per day at a different time per day) my usage was between 0.041kW per half hour and 0.049kW and this difference can be explained by my fridge cycling on and off but what could cause a spike of 300% once a day? We have gas hotwater and no security lights hardwired in. I can't think of anything else that would use power? 
Is it just AGL fudging usage so they can get a few extra cents out of me.....But they do 1cent per day per customer & you have 1 million customers then that's $10,000 dollars per day extra that they are falsely charging customers.
My next question is... I am struggling to understand how the demand tariff is calculated on my account. I have read the examples that the chat people keep providing me but I can't relate it to my account. I want to know how I can reduce my bill and save energy. I'm quite a smart young lady but this demand tariff has me stumped. Happy to share my usage if someone could help me understand it.
I'm on the verge of changing energy providers as AGL have not provided any customer service or answers to my simple questions.
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AGL do not fudge any data (that would be illegal). The data is supplied by your smart meter to a remote site and then passed on to AGL.


You have stated that you only used 2.35kW a day (.049 * 48) during your 5 day break.


Maybe I can explain your spike by suggesting that it is your Fridge/Freezer doing an auto defrost cycle?


Now just to throw a cat amongst the pigeons I'll let you know that AGL are changing users with smart meters to 5 min reporting, the Standard used to be 30 min reporting and they are doing so without informing you.


I get reports from both my retailer (AGL) and my supplier (SA Power Networks). So I know that on the 7th Sept 2023 my meter went to 5min reporting.


Now the data from AGL in the MyUsageData report is supplied in 30 min intervals still but you are now charged on 5min reporting if you have been switched to this.


A demand tariff  takes your highest usage in a set period then multiplies that to get a kWh figure that is applied as a PENALTY against you for that whole month.


So you pay for all the electricity you use plus the surcharge (demand charge).


If you have ½ hour readings the highest reading is taken (during a set period) it is then multiplied by 2 to give you kWh demand charge.


Above is a sample of my usage which I have limited to 6 hours for easy visibility.


You can see that at 2 am I had a max of .427 kW. So that would be multiplied by two and become my demand charge for the month of Jan. (Thus .854 kWh)


Now you can see on the 27th I had a .419 figure only .008 less than the .427.

Again for easy visibility I will show you my same 5min intervals.



You can see that at 20 mins past midnight I had a reading of .072 now with 5 min intervals it is .072*12

(max * 12 because there are 12 five minute intervals in an hour) which gives a total of .864 kWh.


I can tell you though on the 27th my max 5 read was  .090 kW so the demand figure would become  1.08 kWh.


For Jan if I was on demand Tariff  my charge at the moment would be .245 * 12 or 2.94kWh !!!!


So hope this helps.

Cheers Neil

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I understand that fudging the figures is illegal but when AGL can't give a reasonable explanation as to why my electricity spikes, it makes one wonder !!


Nope you have just totally confused me... So how did you get 0.09kW max read on the 27th? and where did you get 0.245 from? See this is my issue, I want someone to look at my bill & tell me where and how the demand is calculated. You can throw all the samples & examples at me but I can't follow. Sorry.

Also isn't demand calculated for the whole month, (ie multiplied by 30/31 days somewhere)?



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OK I explained a possible reason for your spike, "YOUR FRIDGE GOES INTO A DEFROST CYCLE".


I also tried to tell you that AGL (or any other RETAILER) simply charges you for the electricity you use.


Supplied you with examples that allowed me to show you ON SCREEN the variations of the data.


Now a 5 min data file contains 12*24 columns of data for each (ie 288 columns) and a 30min data file contains 2*24 columns of date (48 columns) of data FOR EACH DAY.


Below is the NEM format file for the 29th Jan for my usage (30min)


Now here is the same file in 5min NEM format file.

Sorry cannot show you because above is whole day at half hour and you just have to imagine the line shown above but 6 times smaller.


Now as to:

"For Jan if I was on demand Tariff my charge at the moment would be .245 * 12 or 2.94kWh !!!!"

That refers to UP TO THE 27th JAN my max 5min reading was .245 kW.

Multiply that by 12 and you get my CURRENT daily demand charge.

So multiply that by the number of days in Jan and you will get 2.94*31 or approximately 90kWh.


Personally I would not go on a demand tariff at my current daily usage of 6.59 kWh means I would pay a SURCHARGE of 2.94kWh per day.


To compound this I have 6.6kw of solar on the roof which is giving me 28.6 kWh a day feed-in daily.


I self consume around 4.5 kWh of the power I generate every day to heat my HOT WATER and other power during the day.


Now if you want to Private Message me I will send you an email address where you can forward your USAGE DATA file. I will then convert it into a NEM format file and supply a report based on criteria you supply.

This would be free.


Any way, if you want an answer from AGL about your usage you will get a reply that basically states for about $600-900 you can get your meter tested, if the testing shows no errors then you pay the full amount.


You are basing your FACTS on 5 days while you are on holiday, I check my data on information that I have maintained since the Smart Meter was installed on these premises.


Now the bills that AGL give me are always less than the amount that I have calculated but are always in the same DOLLAR amount.


I wish you good luck in your endeavors.


Cheers Neil


Cheers Neil

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AGL Moderator
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Hi @Kelzna. We only see what goes through the meter, not the source of the demand, so we wouldn't be able to tell you what has caused that spike beyond what has already been offered in the thread. What we can do for you is just check that the metering data is valid. I'll just send you a private message to get started. Regards- Mark

1 Reply 3875 Views

I’m with you…..very hard to contact agl and get a simple answer like what time is the demand period. Also, how is it fair that usage is based on the one day highest usage (say you had a party and lots of stayovers one night) and had very low usage the rest of the month….surely there should be an average of the two.

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For the life of me I cannot understand why anyone would want to go on a demand rate.


Now if you used 2kw a day for power and were on a demand rate you would get charged 1kw per day. (The minimum demand rate is set at 1kW).


Just went and had a look at Energy Made Easy and found this listed for an AGL Demand Tariff for South Australia.

Demand Charge Peak* c/kW/day
* Peak period applies 4pm - 9pm weekday and weekends all year. A minimum demand of 1.0 KW applies.
Now why do they say 4pm - 9pm weekday and weekends all year.
Wouldn't the statement 4pm- 9pm daily be more concise.
Now on the AGL website it states that DEMAND CHARGES ARE MONTHLY but there is no mention of this on the document that becomes your billing if you take this option.
You DO NOT HAVE TO TAKE what AGL Offers you, they rely on people assuming that as a CUSTOMER they are offering you the best rate, but do not do that.
You can change your PLAN ONLINE at any time and the rate takes effect from the time (MIDNIGHT) that you get the email saying you have changed your plan.
I am not going to waste my time telling you how to change plans as this is a WELL DOCUMENTED PROCEDURE and I get no thanks for doing so.
Can also tell you that AGL is changing customers to 5min reporting so the formulae for calculating the DEMAND RATE will be, HIGH READ * 12, rather than, HIGH READ * 2, for the demand kWh.
Okay so here is my 5min reading .26 kW (*12) = 3.6 kWh for the 1st July 23 my 30min reading was .97kW (*2) = 1.94 kWh.
If I take up to the 13th July for 30min reads I get  .97 (*2) = 1.94 kWh for the 13 days but with 5min reads I get .31 (*12) = 3.66kWh for the 13 days.
No wonder people ask how do they get such a high figure 3.66kWh verses 1.94kWh.
When I queried SA Power Networks as to why I went to 5min reads they told me that my Retailer had requested it, yet AGL never informed me of the change and still continue to supply readings in 30min format to me.
I am lucky in the fact that I have access to both the files so I can compare the data.
Demand charges were designed as a TAX on business customers to get them to reduce their usage. Now my housemate caused that peak when she put the microwave and the toaster on at the same time. It dropped the breaker but the meter still managed to read the usage and report it.
Any way good luck with demand.
Cheers Neil

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Thanks….I didn’t realise I had a choice re the demand plan. The letter just stated that it was happening. Thanks for the info 👍🏻👍🏻

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That's some impressive analysis there!

It does, however, just go to show that demand metering does nothing to make electricity pricing and monitoring simple for the average consumer.

I would STRONGLY recommend against demand based metering for ANY consumers UNLESS they can run spreadsheet software AND have access to accurate reading data AND their retailer/distributor can GUARANTEE that all times are synched via NTP to a strata-1 time source.
And if you don't understand any of the words in the paragraph above, well, the power companies understand it. Trust me - they bank on the fact that you don't.
And the first power company that offers me the cheaper of two prices - demand and single rate - IN AREARS - will get my business.