Irrigation Interruptibility Scheme

Irrigation uses a significant amount of electricity in central Canterbury.  Orion operates a scheme where we pay rebates to customers who let us interrupt the supply to designated irrigators during a capacity emergency to help us keep the power on for the wider community.

The Irrigation Interruptibility Scheme means we can interrupt the power supply to some irrigators leaving sufficient capacity remaining in the network to continue to supply electricity to more essential services, such as dairy sheds and medical centres.  It also means Orion doesn’t need to invest as heavily in contingency assets and the savings from this reduced investment supports the rebate and lowers the overall cost of electricity supply.

When is it used?          

In a capacity emergency, we may interrupt the power supply to irrigation connections that are part of the scheme.  Capacity emergencies include:

  • failure of a line resulting from severe weather, such as high winds
  • a fault on the network resulting from a car hitting a pole
  • a fault in switchgear or a transformer at a district substation
  • a capacity shortage on Transpower’s grid that creates a shortage

In any one area, we expect such events to occur approximately once in five years, with a maximum duration of eight hours, and once in ten years with a maximum duration of 48 hours.  There could be more or longer interruptions under extreme circumstances.

We restore supply to irrigators as soon as possible but will give priority to the restoration of other services.

Each irrigation season we may turn the power off to irrigators that are part of the scheme for 30 minutes to test the level of load response. Tests may occur at any time of the day and will be carried out without warning. 

Eligibility & rebate

The interruptibility scheme is available for connections with 20kW of irrigation pump capacity or greater, and in most cases it is optional. In a few cases, this is a condition of connection.  The rebate is based on the size of the load that can be interrupted at the connection. 

Check that the scheme is available through your electricity retailer – to be eligible, your retailer must also:

  • ensure an appropriate interruptibility relay is programmed to the channel Orion allocates, is installed and maintained at the connection and report any changes to the relay to us, and
  • maintain metering equipment at the connection that, at least, records kWh loading levels on a half-hour interval basis, and provide this to Orion on a monthly basis using an industry standard format

Questions?

If you have any questions, please call us on 0800 363 9898 or email us on irrigation@oriongroup.co.nz.