How is the Demand Tariff determined?

[Giff]

I am trying to understand how the "Demand Tariff" is determined.

AGL Description: Demand Charges are based on the load you place on the electricity network. It is measured over 30-minute intervals during your demand time period. The highest measure for the billing month is used to calculate your Demand charge for the entire month.

The unit for charging is c/kW/day.

As this is kW and not kWh, I presume this is the peak "instantaneous" kW consumption during the any 30-minute interval during the demand time period. [it would seem that the 30-minute interval is redundant]

[-Nam- · Accepted solution]

Hi Giff! 

Demand charges can vary depending on your electricity network, based on what you've advised, your Demand Charges are calculated by using the highest recorded kW in a set period time (this is outlined in your confirmation pack). The kW recorded in that 30 minute interval is then used for the highest value for that hour, then applied for that billing month. 

Hope this helps! 

-Nam- 

[Giff]

Thanks for reply Niam. Are there any plans to show the Demand number in the online app so users can monitor this? 

[-Nam-]

Hi Giff! 

Not at this stage however, we are always updating our online services so watch this space for updates! 

-Nam-

[NeilC]

@Giff @-Nam- 

You should check with your SUPPLIER / Distributor.

In SA the ONLY supplier is SA Power Networks.

You can log into their web page and see (and download) your daily info for up to the last two years data.

The round dots on this are your peak demand data ( The highest dot in the image above is 1.6kW).

By the way AGL is your retailer, the company that supplies the wires to your residence is your Supplier / Distributor and is listed on your bill.

Located on the top right hand side.

Your supplier is who you contact when you have no power or an emergency (line fallen etc).

In SA on their web page you can sign up for alerts and check outages etc etc.

To find your Supplier / Distributor :

      https://www.aer.gov.au/consumers/who-is-my-distributor 

Then check their websites to see what services they supply.

Cheers

Neil

PS:

If you find a post that is helpful please take the time to click the LIKE button to show your gratitude for the information supplied.

[Palmplex]

Your explanation sounds simple but it doesnt help.

What has the 30 minutes got to do with finding the instantaneous peak ?  Is it averaged over 30 mins ?  Or do you find the median peak ?  If the peak at say 8kw lasts 60 seconds , is it different to 8 kw lasting 5 mins ?

Please explain with examples ?  Over what time period is the instantaneous peak measured ?  per second , per millisecond?  If in a 30 minutes segment I use 8kw constantly for 15 mins, then zero for the other 15 mins is the measured peak for billing purposes 4kw ?  

[NeilC]

@Palmplex 

https://www.canstarblue.com.au/electricity/demand-tariffs/ 

Try reading the site above or doing some research on the web.

Now meter usage is transmitted from your meter to a collection site every 30min. It is a number with 3 decimal points.

Solar	20/09/2020 11:00	20/09/2020 11:29	1.640
Generalusage	20/09/2020 11:00	20/09/2020 11:29	0
Controlledload	20/09/2020 11:00	20/09/2020 11:29	0
Solar	20/09/2020 11:30	20/09/2020 11:59	1.746
Generalusage	20/09/2020 11:30	20/09/2020 11:59	0.001
Controlledload	20/09/2020 11:30	20/09/2020 11:59	0

Above is a random sample from my AGL data file

So in the first half hour I

                 exported 1.64kw to the grid.

                 used nothing from the grid

In the second half hour I

                 exported 1.746kW to the grid

                 used a MASSIVE .001kW from the grid.

My controlled load meter is not connected to anything and would not be showing anything if it was because the time is nearly midday.

So for that one hour period I will get paid for 3.386kWH and will get charged for .001kWH.

Now I can't tell you if the ,001kW was an instantaneous peak, took 12.889ms but that's what happened. If that was in my demand time that would be ignored as only the highest figure is used.

Now that is all the information that is available from the file.

If you have the ability to decode the file you could do your own analysis, if you don't then you will just have to accept the figure when it is presented on your bill.

Now I can tell you that on the 18th April between 1800 and 1830 I had a .8kw usage for the half hour. But, on the 13th April between 1930 and 2000 I had a MASSIVE 1.1kw usage.

So after you have read the Canstarblue web page and you actually know the figures you will have an approximate guess of what your demand tariff will be.

I can tell you that we are having overcast days (with no rain), I am 12% into my current billing cycle and that my 90 day bill (at the current rate) will be $13.86 or is costing me $0.1540 per day.

Now that is inclusive of my Supply Charge, my electricity usage and the payment received from my solar. To pay off this massive bill I have to pay $2.00 per fortnight to AGL so as not to receive a bill payable.

The trouble with demand is that you need to know what it is so that you don't exceed it and pay more.

In the last year my MAX demand for a day would have been 1.475kW if I was paying it.

Cheers Neil

[Giff]

Thanks Neil @NeilC and @Palmplex for taking the time to respond.

My initial (wrongful) impression was that as the measurement was kW, it doesn't have a time component, hence I "assumed" that this would be some sort of instantaneous kW value.

After reading the Canstar artticle (thanks @NeilC) the kW value is the actual kWh consumed over a 30 minute period. Maybe the units used should be c per kWh per day, where kWh = the highest kWh consumption during any 30 minute interval during the peak times during the month.

I have been communicating with AGL (NSW) and they have no mechanism to inform consumers what their peak 30min kWh value is at any particular time. Ausgrid don't seem to have anywhere that the meter information can be downloaded from. Note: you can view the 30 minutes consumption on the AGL app after a day or 2, but it's a very manual process to check each day.

I think I may start looking for another supplier, as this demand tarriff has the potential to be very expensive. I get the "peak load" thing, but in a household you only need to run the AC, clothes drier, iron etc, all at once on a cloudy day and you get slammed for the whole month. Quite crazy as most days we are a net energy supplier.

giff

[Giff]

PS found the Ausgrid meter data request page.  Can't wait to get it loaded into a spreadsheet!!

[NeilC]

@Giff @Palmplex 

Hi to you both and thanks for the likes.

Now the NEM Format file is a spreadsheet in Comma Separated Format (.CSV) that has a 200 Line that indicates :

200

XXXXXX

E1B1E2

E1

E1

U260000657

KWH

30

Column1  : Meter Description

Column2 : Meter Number

Column3: Meters in the report

Column4: The meter in the next report

Column5: The meter in the next report again

Column6: A Blank line

Column7: More meter Info

Column8: Meter usage rate

Column9: The report info time in minutes

The next row will report a 300 line:

300

20200429

0.146

0.119

0.147

First is the report number in column1

Column2 is the date in format YYYYMMDD

Then column3 to 51 show the half hour figures (if 30 min reporting) column3 to column99 if 15 min reporting 3 to 99 show 15 min data.

Then all the data until you reach either a 900 data row (end of file) or the next 200 row.

There are a multitude of report rows (400,500,600,700,800) that may appear in the report but they are meter corrections in the report file.

So if you can  understand a spread sheet and can convert date to time in a single 300 row you can decode the data.

For me its pretty easy but for some not even possible.

I do this every day (or not) but can track my Usage or Export for the last two years in either NEM or meter data format.

Now I can tell you that in very situation that I have analysed for many people on the AGL community pages I have never found that DEMAND is the best result.

If you are using DEMAND changing retailers is not an option as you will end up paying about the same price.

Demand, if you have to use it, is best on monthly billing because you only pay the high rate for 30 days.

Go to the https://www.energymadeeasy.gov.au/  website and check what options are available to you.

I live in SA and there are 166 plans available for me??

Again hope this helps.

Cheers Neil

Now I don't work for AGL nor have ever worked for an Electricity Retailer, I do have experience in running and maintaining diesel power stations in marine and land based situations.

I go on these pages to try and assist people that ask questions.

Again I will ask persons that read replies, to click the LIKE or RESOLVE buttons show their appreciation to the persons that take the time to reply.