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Network load management Network load management

Information as at 19 October 2017   8:02 p.m.

Current loading and load management measurements

Orion normally controls load to keep it just below our network limit (currently 575 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.

Network load Shedding Uncontrolled load Shedable Restorable Temperature
345 MW 0 % 345 MW 51 MW 0 MW 14 °C

Pricing periods

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 peak periods (for general connections) and control periods (for major customer connections).  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:

  Current
uncontrolled
On
(MW)
Off
(MW)
Group Status Current period
duration (min)
Major customer control period 345 MW 595 575 1 Off 0
      2 Off 0
General connections peak period 345 MW 590 570   Off 0
Generation period         Off 0

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.

Load Graphs

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 network 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:
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The Orion's network load and load management chart showing PercentShed series, Uncontrolled series, NetworkLoad series, Limit series, ControlPeriod series, PeakPeriod series, GenerationPeriod series.
                
The Network load, upper South Island region load and temperature chart showing NetworkLoad series, USILoad series, Temperature series.