Irrigation demand control

Reduce peak irrigation power consumption now and help reduce Transpower’s electricity network transmission charges in the future.

From 1st April next year Transpower’s charges to Mid Canterbury (affecting EA Networks customers) will increase by $10.2 million. Electricity network charges will increase because of this. For farmers who irrigate this will be an increase of approximately 40% (about $5,000 per 100kW per annum), though all Mid Canterbury electricity customers are affected by the charge.

The increase is the result of high summer time peak energy demand, driven by irrigation demand during December 2017 combined with industry regulations that require Transpower to use peak energy demand to allocate costs to each region across New Zealand. Transpower do not get an increase in revenue because of this movement – it is simply a reallocation between regions based on the relative energy demand between each.

Reducing summer time peak energy demand is the best way to lower Transpower’s network charges in the future. Voluntary day time reduction of some irrigation energy demand (where possible) is essential to achieve this. We are asking all irrigators to participate in voluntary electricity load control management on their properties to help reduce Mid Canterbury’s peak energy demand this irrigation season.

View our Irrigation Demand Control Schedule and read our recommendations below, to find out how you can help manage peak energy demand this summer to reduce future costs. Register your mobile phone number with us to receive all necessary reminders and alerts regarding recommended load control periods.

TEXT the word “Power” from your mobile phone to 4040 to register.

If nature plays its part and delivers useful rainfall and lower temperatures across the next month, this will naturally reduce the need for irrigation. However, if the coming weeks result in low rainfall and high daytime temperatures, the risk of summer energy peaks is high. We are seeking to reduce these peaks through your actions supporting this voluntary initiative.

This is a serious matter, with over $10 million of additional costs leaving our local economy next year. We look forward to working with you to try and reverse this in the year following and beyond. 

 EA Networks recommends: 

  • Continue to irrigate all critical crops as you require.
  • Identify resilient pasture and consider reducing irrigation to these areas.
  • Reduce irrigation use as much as possible between 8am and 8pm Monday to Friday, as detailed in the schedule.
  • Irrigate as much as possible across weekends and overnight.
  • Register for TEXT message alerts and reminders so that you can stay informed.

Why are Transpower’s charges increasing?

Transpower is regulated, and the way it allocates its ‘interconnection charges’ based on peak energy demand across New Zealand is prescribed by regulations. Regions that demand more energy at peak times are allocated their greater proportional share of Transpower’s charges.

Historically peak energy demand has occurred during winter. During winter Mid Canterbury’s energy demand is typically around 5% of the Upper South Island’s total demand. This means Transpower would allocate 5% of their group interconnection charges to Mid Canterbury.

However, due to increasing summer time energy demand, summer peaks can occur. When they do, Mid Canterbury’s share of total energy demand increases to 20%. The increase compared to winter is due entirely to irrigation use in the region. As such, when summer peaks occur, Transpower allocate Mid Canterbury a proportionally higher share of their interconnection costs.

In the current financial year, interconnection costs for Mid Canterbury are $4.3 million due to mostly winter peaks in the prior year. For the next financial year, Transpower are allocating $14.5 million in charges to Mid Canterbury because of the summer peaking issue.  

Weather is the primary factor that determines winter vs. summer peaking events. A summer with good rainfall and lower temperatures, followed by a cold winter, will typically result in a winter peaking situation (lower costs to Mid Canterbury). Counter to this, a hot and dry summer, followed by mild winter can result in a predominantly summer peaking situation. This is a poor outcome for Mid Canterbury since summer peaks drive higher Transpower charges.

How can you reduce this cost in the future?

Only through reducing energy demand at peak times can Transpower’s costs be reduced. In Mid Canterbury this can only be achieved by reducing irrigation demand during certain times.

Active steps can be taken to reduce the likelihood of summer peaks. Reduction in peak energy demand is most important during the following conditions:

  • On a weekday (Monday through Friday)
  • During the daytime (between 8am and 8pm).
  • When temperatures are high.
  • When there has been low average rainfall.

How much does energy demand need to reduce by?

Irrigation energy demand across Mid Canterbury can be as much as 140 megawatts (MW). We are seeking to reduce this to 90MW (or less) during the days and times recommended. This represents an energy demand reduction of about 35% across the district.

What can I do?

Reduce any non-essential irrigation use on your property between 8am and 8pm Monday through Friday during the periods recommended by EA Networks (refer to schedule), or as recommended through the TEXT message alert system.

Why should I reduce my irrigation demand?

So that you can get lower network charges in the future.

Transpower’s charges can only be reduced if collectively Mid Canterbury’s energy demand is reduced during summer. This can only be achieved if irrigation demand is reduced, either naturally through rainfall/lower temperatures OR through active reduction on-farm by you.

By reducing irrigation demand, and in-turn collectively reducing Mid Canterbury’s energy demand, our region will be best placed to get lower charges from Transpower.

But I have critical crops that must be irrigated.

You are best placed to determine which, if any, irrigation demand can be reduced during the periods that we recommend. For non-resilient/critical crops it may not be possible to reduce irrigation – this is OK since we are not seeking to reduce all irrigation demand, just 35% of the total and only during specific times/periods.

When should I reduce irrigation demand?

We have developed a schedule that details when we recommend that you reduce irrigation demand on your property. Outside of these times/days you can freely irrigate to the fullest extent since there is little risk of a summer peak occurring. See the attached schedule for details.

Reminders and alerts.

We have established a TEXT message reminder and alert system. By registering your mobile phone number (and the numbers of anyone involved in managing irrigation for your farming operation) we can send you reminders and alerts.

  • Reminders: Sent mornings and evenings on days we recommend you reduce irrigation demand.
  • Alerts:  Sent only when we see peaks emerging. The purpose of an alert is to recommend additional voluntary reductions in your irrigation demand.

To register your mobile to receive these messages TEXT the word “Power” to 4040.

Please Note:  Only mobile phone numbers are required (no names or other details) and your mobile number will only be used for load management reminders and alerts. You can OPT-OUT at any time.

For more information please contact us on 0800 430 460 or email