# Energy Management

Looking for tips or advice on energy efficiency around the home? See what others are doing or share your experience!

Looking for tips or advice on energy efficiency around the home? See what others are doing or share your experience!

## Demand rates

Switched-on

Hello,

I'm a newbie to this forum.

I dont really understand the AGL's "General Usage Demand Opt-In" rates.  The demand charge is in units of c/kW/day for usage between the hours of 1500-2100.  That doesnt appear to be a unit of enrgy consumption, do they mean c/kWDay or c/kWHr ?   Is it an additional charge on top of the normal c/kWHr rate?  Can anyone give me a simple worked example of how this rate works ?

thanks  Jan

24 REPLIES 24
AGL Moderator

Hey Jan05,

Thank you for getting in touch!

Demand charges are calculated by looking at a customers highest 30 minutes of energy usage during this peak time for the billing period Mon-Fri (excluding public holidays). This amount is then used to calculate the customer's bill and is reset at the beginning of the next billing period. This means that if customers lower or restrict how much power they're using during those peak times, they can potentially save on their final bill.

The formula for calculating this charge is as follows: KW consumption x Days in billing period x Demand charge.

For example, if your highest 30 minutes of usage for a 90-day billing period was 9.6KW with a demand charge of 15c, this'd be calculated as follows: 9.6 x 90 x 15 = \$129.60 (excl. GST).

Hopefully this helps!

Cheers,

Jayden

If I’ve helped in anyway, please mark my post as SOLVED!

This helps our Community know the answer to common questions.
Switched-on

Thanks Jayden that makes it much clearer.

A followup question:  is the demand charge in addition to the normal c/kwhr consumption charge during the demand period or does it completely replace it?

thanks  Jan

AGL Moderator

Hi Jan05,

The demand charge is in addition to the usage during these periods, however it's important to keep in mind that you receive a considerably lower kWh rate in exchange for the demand charge.

Kind regards,

Jayden

If I’ve helped in anyway, please mark my post as SOLVED!

This helps our Community know the answer to common questions.
Switched-on

Hi Jayden,

How do determine the highest load within 30mins from 3pm - 9pm?  I mean I download my usage data from powercorp and all it gives me is my consumption, kW-Hr, on a 30-minute interval.  Reason I am asking because the calculcations you've shown as an example is hard for to simulate using actual data.  In my case, I know the actual electricity bill before the actual invoice comes into my inbox, and now that I am planning to switch, I trying to undertand that method of calculation for the demand charge.

Thank you!

Switched-on

Why is the demand rate "normalized" over 30 days when I have a smart meter installed  AGL knows exactly how much was used at any given time during the demand period?  Applying the highest 30 min across the entire month feels like a bit of a stretch from an "estimate" standpoint considering we all know how much is being used in 30 min intervals.

Switched-on
• If we get this demand charge, why do we also get charged usage, example, My usage was 140.771kwh price \$0.1559 amount \$21.95

Demand 5.144kw price \$0.2404 amount \$33.39

this was for a period of 27 days

so for one day where I used a little extra power I’ve been charged an extra 150% or you could say my usage was charged at \$0.1559 + \$0.2404=\$0.3963
Doesn’t make sense

Switched-on

I’d rather have a higher usage rate and no demand, but I’ve been told I can’t do that

Switched-on

You use the example of  "For example, if your highest 30 minutes of usage for a 90-day billing period was 9.6KW with a demand charge of 15c, this'd be calculated as follows: 9.6 x 90 x 15 = \$129.60 (excl. GST)."

Usage is generally referred to as energy used over time ie kWHr. Demand is usually referred to as KW and is a measure of delivery of power at a given time. So, for example, 2 KW supplied consistently for 1 hr would give usage of 2 kWhr, 3 KW for 30 mins would be 1.5 kWHr.

In your example, you refer to usage of 9 KW which is not consistent with the usual definitions. Please clarify. Are you saying that the usage for the highest 30 min period is 9.6 kWHrs (not KW) and that your tariff defines the demand calculation to be 9.6 x 90 x 15 etc.

Clarification is needed as in engineering, 9.6 kWhrs for 30 mins requires a delivery of 2x9.6 = 19.2 KW demand. Please clarify that you are using the measure of energy for the 30 min period as the KW figure.

Also, can you please provide the link to the source document (legislation, regulation, gazette etc) where these tariffs are officially defined.

Thank you.

Tags (1)
Powerhouse

What was stated was that the usage for that half hour period was 9.6kw.

Say in the second half of that hour they used 6Kw then the usage for that hour would be 15.6kw not the assumption that you made.

In billing you pay for the number of Kw used.

Your meter is a consumption meter and shows the amount of electricity consumed.

Using a NEM format file below is my usage from midnight to 2 am on the 28 Apr 2019

 Date 00:30 0 1:00 01:30 02:00 20190428 0.445 0.175 0.191 0.191

Between midnight and 1am I used .62Kw and that's what I got charged for.

You are referring to average Kw, so in the brief period I have shown above I consumed 1.02Kw.

Now that was 2 hours so my average consumption for that period was .51 kw per hour.

My understanding is that you have selected Demand as your choice of supply, (we do not have that option in SA), selecting this option is your choice and can still be cheaper than paying full price for your electricity which may be paying a full higher rate for all of your consumption.

In my case my Electricity plan states that I will pay 39.19c/kWh which means I will pay 39.19c for each kilowatt I use, so if I use 10Kw in 1hour I will pay 10*39.19 or \$3.92 for that one hour period.

Hope this helps

Neil

Can't find what you're looking for?