Network load management

Alert: Thursday 19 October 2023

Data will be unavailable on this page on Thursday 19 October 2023 due to system testing and maintenance. This page will have data available again on Friday 20 October 2023.

We apologise for the inconvenience.

Orion normally controls load to keep it just below our present limit (635 MW).  We also control load for other reasons, including to avoid localised peaks, to limit our contribution to the region load on the national transmission grid, or in response to faults or emergencies.

A significant proportion of our costs are driven by the need to meet peak loading demands.  To ensure that consumers make appropriate decisions about when and where to use electricity, we signal this cost driver in our delivery charging via the use of the use of control periods.  Our regular load management tends to flatten out any peaks, so we calculate “uncontrolled load” (our estimate of the loading levels that would have occurred if we had not controlled load) and use this to trigger our pricing periods.  We adjust the on and off trigger points throughout the year to focus on the periods of highest loading without exceeding our target annual duration.  The current trigger points and status of pricing periods are:

Note that pricing periods have minimum durations and our system has load checks to ensure stable operation of the signals – this results in delays for a pricing period to turn on or off once the trigger is reached.

The following graphs show our current load and load management activities, or you can use the date selector to view graphs from previous days.
Note that the limit (the black line) is set as a target to keep costs and prices down. The network can cope with higher loading levels, but we will then need to invest in more capacity to maintain an appropriate buffer for growth and security.
Also note that the uncontrolled load (the red line) is not the actual loading level – it’s an estimate of the loading level that would have occurred if we hadn’t tried to keep it down.

Select date to graph:

Loading… September 2026 Mon Tue Wed Thu Fri Sat Sun 36 31 1 2 3 4 5 6 37 7 8 9 10 11 12 13 38 14 15 16 17 18 19 20 39 21 22 23 24 25 26 27 40 28 29 30 1 2 3 4 41 5 6 7 8 9 10 11 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec TodayClear

Our load management primarily focuses on storage water heating, where supply can be interrupted for a period of time without affecting the availability of hot water.  Our control simply delays the heating of water cylinders until the peak load or network constraint has passed.  To ensure that customers are not adversely affected by our load management activities, we agree a set of long term service level targets with electricity retailers.  We then aim to limit load (and therefore delivery costs and charges) to the maximum extent possible without breaching these agreed service level targets - this is a challenging cost/quality trade-off to achieve, and we actively report on our results.

The following tables show the extent of shedding for residential and business customers with water heating linked to an ‘economy’ or ‘composite’ electricity option. Customers with night option or night with an afternoon boost are not affected by this load control. Numbers in the table are in hours and minutes.

Residential load management channels Service level target: No more than 4 hours off in any 8 hour period Performance: Average duration (hours off) Longest duration (hours off) In the last 8 hours (see graph) 0:00 0:00 In any 8 hour period today 0:00 0:00 In any 8 hour period yesterday 0:10 1:00 The following spreadsheet shows a history of residential water heating service performance: Residential water heating service performance history (xslx)

The following spreadsheets provide a history of our pricing periods:

Orion injects ripple signals into its network to identify its pricing periods (peak periods, control periods and generation periods) which are used to establish charges for delivery and credits for export and generation. The records of these pricing periods, as listed in the linked spreadsheets, are verified at the end of each season.

Orion also provides email and text messages to notify pricing periods and a range of other information which is displayed on the dashboard web page. These additional messages and information are provided to assist customers and retailers, but their accuracy and availability is not guaranteed. In our experience, email and text messages are occasionally delayed or lost and, from time to time, the information on this web page may not be available or may be incorrect. We do not accept liability for any direct or indirect loss or damage that may be suffered as a result of using this additional information.

Data may infrequently be incorrect/incomplete due to system testing.

Please email us if you find any errors on this page or have any comments or suggestions for improvements.