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]

[Giff]

Thanks @NeilC 

I requested and have received our meter data from Ausgrid.

In our case we have two "300" lines for each date.  There is no differentiating data between the two lines, but the first is the feed-in data and the second is the consumption data.

Interestingly,

(1) the  00:30 - 01:00 column contains zero for all the "300" rows. I plan to take this up with Ausgrid as AGL seem to have data for that time period.

(2) comparing the Ausgrid meter data with the AGL data in the app, the AGL values seem to be double the Ausgrid values. I'll be doing some more research on this, and will publish a new thread if this need additional comment.

[Giff]

I can answer my own question.  

Although the Ausgrid data suggests 30 minute data (Record 200), there are actually 48 columns of data, hence, 15 minute data.

Still doesn't answer the question as to why column 4, the second time period column is all zero. 

[Giff]

Ausgrid are determined to make this as difficult as possible.  The data is a mixture of 15 and 30 minute durations.  They throw in extra "200" records to change the durations.

[NeilC]

@Giff

OK lets work what is 30 min data and what is 15 min data.

I explained to you what a 200 line is.

I explained to you what a 300 line is.

Now for some reason you think:

Although the Ausgrid data suggests 30 minute data (Record 200), there are actually 48 columns of data, hence, 15 minute data.

Now I tell you that there are 51 columns of data  and I quote:

"Then column3 to 51 show the half hour figures (if 30 min reporting) column3 to column99 if 15 min reporting "

Now believe it or not in 24 hours there are 48 * 30 min periods. So in simple maths there are 2*30 min periods in an hour.

So for one day there are 24 (hours) * 2 (2*30 min periods)  = 48 collection data columns.

If its 15min data collection it is (4*15 mins) * 24 = 96 collection data columns

Now I have just read your latest reply whilst writing this.

So you are saying you have FOUR 200 Lines, I have already explained this.

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

So when the meter reports in 30mins you have a 200 line and then the 300 data

When it reports in 15mins you have a new 200 line and then the 300 data.

In the past I have offered to review  peoples data (for free) on this site, but I no longer wish to do this as I get no thanks.

I suggest you look at the data file from AGL and look at times what the data is. My most recent attempt to help resulted in finding that the NEM format file contained four sets of data (two in 15min intervals and two in 30 min data), his AGL file contained only data in 30 min intervals and did not match any of the data in the NEM format file.

No thanks from the person...

Now I hope this helps, if you like what I replied to you please click the like button to show your appreciation (note you should do this for any post you see that you like.

Cheers Neil

[Giff]

Hi @NeilC 

Thank you for your reply. 

As you have mentioned the data does contain multiple “200” records where the data switches between 15 and 30 minute intervals. 

I will now have some fun writing some Excel macros to consolidate and unify the data. I will then be able to determine the monthly peak demand. I will then be able to accurately compare plans. 

Incidentally, my data file from Ausgrid has one column of usage data which is all zeroes. Column 4. 

Have you seen this before?  I have opened a ticket with Ausgrid. 

[NeilC]

@Giff 

Without seeing all of the actual files no I have not seen it.

Having a guess I would say it was a Controlled Load File where metering does not start until 00:30, hence the first amount would be from 00:30 till 01:00 for the first half hour.

Metering times should be on the Ausgrid Site (and are) but I did not look deeply into them.

Cheers Neil

I you like my reply please click the LIKE button.

[Giff · Accepted solution]

Cancel the zero value column issue.  Excel had formatted the column as an integer which became zero as the value was less than 0.5.

[mattanderson]

I would like to know what time period is used for calculating the demand usage charge.

[Giff]

30 minutes. 

The smart meters report energy usage (kWh) in 30 minute increments. The highest value on eligible days during peak hour periods during the month is then used. 

This value is then doubled to give the peak demand in kW. 

[mattanderson]

and what are the peak hour periods?

Matt Anderson, Partner
Clayton Utz
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