Power Outages


We recognise outages may be difficult for some customers to manage, however our priority is ensuring we can maintain a safe, reliable, quality supply of electricity throughout the network.


In an emergency (e.g. car accident involving power lines or a transformer fire), call 111.


Call our 24-hour Faults Line 0800 30 90 80
MainPower NZ Ltd
Planned & Unplanned Outages Map

If there's no power at your place, check out the current & planned outages map to see if you're affected by either a scheduled maintenance power outage or a fault. If your outage isn't on the map or for more information, call us on 0800 30 90 80.

MainPower carries out regular maintenance and upgrade work across North Canterbury. From time to time, you may be affected by a planned power outage. If this is the case, you will be notified ahead of time by your chosen electricity retailer.


Unplanned power outages can also occur at any time. Typical causes of unplanned power outages include stormy weather, tree branches and other debris falling on power lines, or car accidents. Check the Power Outage Safety tab for advice on what you should do if you come across one of these situations. Or click here to find out how you can be prepared with a No Power Plan.


Our priority is to maintain continuity of supply and to notify customers of planned interruptions in accordance with our Connection Agreement. When power supply is disrupted, either due to a planned or unplanned interruption or when disconnection is requested by the retailer or an agency other than the customer, every effort is made to ensure human life is not threatened and that legislative and regulatory requirements are met.

Outages FAQs

What should I do during a planned power outage?

If you will be affected by a planned outage, your electricity retailer will send you a letter in advance, so you can make other arrangements.

Planned outages are also listed on our website, visit the planned outages page.

What can my business do to be prepared for a power outage?

  • Check your terms and conditions with your electricity retailer - it will detail notification periods for planned electricity network outages and any compensation clauses.
  • Check your insurance provisions – how long does power need to be off before the policy covers you.
  • Have a good back up plan and ensure your staff are trained.
  • Consider the use of manual eftpos and credit card options.
  • Can your site be supplied by a generator – know your capacity requirements, connection options and generator hire contact details.
  • Have alternative locations for storage of perishable goods and freezer blankets.
  • Have back-up alternative locations to work from and phone diversions to mobiles contingency in place and when the power comes on understand what equipment needs resetting.

Why do power outages occur?

There are two types of power outage, planned and unplanned.


Planned power outages occur when we need to complete maintenance work on the network. If you will be affected by a planned outage, you will receive a notification from your chosen electricity retailer in advance.


Unplanned power outages occur when unforeseen circumstances cause damage to the network (e.g. car accidents, tree branches or other debris being blown into power lines etc.).

Who is a priority customer?

Special consideration is given to the continuity of supply to customers whose health or livelihood could be adversely affected by an interruption. Priority customers include those who maintain essential services as well as medically dependent customers.


Customers with serious medical conditions, who rely on continuity of supply to support life, are treated as priority customers. Every effort is made to maintain continuity of supply and, if necessary, to advise them of any interruptions to supply so that alternate arrangements can be made. If you are a medically dependent customer, please ensure we are aware of your needs by contacting your electricity retail provider and letting them know. Or, contact us on 0800 30 90 80.

Does MainPower charge for callouts?

MainPower provides a 24-hour fault response service. When a customer’s property or actions have caused the fault, the responsible customer will be charged a call out fee.


Call outs caused by a MainPower network fault will not incur a fee.


MainPower call out fees

  • During normal working hours (7:30 a.m. – 5:00 p.m. Monday-Friday)
    • $176+GST minimum for up to two hours, plus travel (charged per kilometer)
    • Additional charges will be billed for any equipment required (e.g. replacement power pole) and time exceeding the initial two hour call out period. Additional time between 7:30am-5pm will be charged at our standard rate ($88+GST per hour).
  • After-hours
    • $264+GST minimum for up to two hours, plus travel (charged per kilometer)
    • Additional charges will be billed for any equipment required (e.g. replacement power pole) and time exceeding the initial two hour call out period. Time will be charged at our after-hours rate ($132+GST per hour).

All chargeable call outs will incur a minimum fee for a two hour period (travel time inclusive). Where we are required to stand staff down as a result of attendance at a fault we reserve the right to charge a stand down fee.

No Hot Water?

MainPower continuously monitors and controls the load on the network to ensure a secure, reliable supply of electricity for our region.


Sometimes, during periods of peak electricity consumption, MainPower switches off electricity supplied to hot water cylinders for a short time to make sure the network is not overloaded.


In New Zealand, most hot water cylinders are controlled in this way by the regional electricity distribution business. Customers who allow their hot water to be controlled will typically pay lower rates on their power bills. To learn more about your electricity billing, contact your electricity retailer.

Load Control

Why does MainPower control load on the network?

MainPower continuously monitors the load across the electricity distribution network of North Canterbury. When necessary, adjustments are made to ensure a continuous supply of electricity for the region. Load control helps to keep the cost of distributing electricity as low as possible.

When does MainPower control electricity delivered to hot water cylinders?

Like roading networks, electricity networks experience peak times when demand is high and capacity is near the limit. On a roading network, this would look like a rush hour traffic jam.

Peak times on the MainPower network typically occur on cold winter mornings and evenings (when most customers are running heaters, lights, and other appliances at once), or in summer when irrigators and air conditioning are running at full capacity. Hot water cylinders are remotely controlled when the electricity network is experiencing high load.

How does load control work?

Electrical load on the network is continuously monitored through our network control system. When areas of the network approach peak load, signals are sent out through the network to switch off the hot water cylinders in the affected area.


These signals are call ‘ripples’ and reach ‘ripple receivers’ fitted to the meter board at each house or business, signalling them to switch off the hot water cylinder. Hot water cylinders are switched back on as soon as the load on the network starts to reduce.


MainPower limits the amount of load control to four-hours within any eight-hour period. In most cases, the effects of load control aren’t noticed by customers. Hot water cylinders store enough heat to stay hot throughout the four-hour window, as well as meeting an average household’s hot water needs.

What appliances are affected by load control?

In New Zealand, electricity supply to most hot water cylinders can be controlled through ripple signals.


In some rare, emergency situations, MainPower may also turn off electricity supply to irrigators through the same ripple control system.

Does load control affect the whole network at once?

Only the part of the network that is nearing peak load will be controlled.

Does MainPower control irrigator load?

Irrigators use a large amount of electricity. Irrigators on the MainPower network may be connected to our emergency load control system. Houses, sheds etc. are not connected to the emergency load control system. Irrigation load is not controlled to manage load on a seasonal basis, unlike hot water.


In emergency situations where MainPower needs to urgently decrease the load on the network, we may turn off the electricity supply to irrigators. This is to ensure continued supply across the region and only happens in extremely rare, emergency situations. If it is necessary to turn off irrigators, MainPower will try to contact affected customers, however this may not always be possible in short-notice, emergency situations.

Medically Dependent Customers


Do you, or someone in your household, depend on electricity for Critical Electrical Medical Equipment (CEME)? Is your health or wellbeing especially vulnerable?


We recommend that you have an emergency response plan in place. We can never guarantee your power supply at all times, as unplanned outages due to unforeseen circumstances can occur. Your emergency response plan could include always having a standby battery that is fully charged and ready to use. It could also include plans to immediately relocate to another address which has electricity supply.


It's important that you register as a Medically Dependent Customer with your Electricity Retailer.


For more information on vulnerable or medically dependent customers, visit the Electricity Authority website.

Troubleshooting Tips:

Check the main switch is on at your switchboard

If a fuse is blown, the problem is likely in your home and you may require a call out from an electrician.

Check if your neighbours have power

If a number of houses in your area are without power or hot water, it is likely the outage is linked to a problem on our network.


Check our outages map for all current planned and unplanned outages

See if we have listed an outage for scheduled work or a known fault in your area.

No Power Plan


Power outages can happen at any time. MainPower's priority is to get the power back on as quickly and safely as possible. In large-scale events such as an earthquake or windstorm, some customers may be without power for an extended period. Having an up-to-date No Power Plan will mean you are prepared, regardless of the situation.

Check out our No Power Plan checklists:


Prepare your home for power outages:
  • Keep your phone charged and consider getting a car charger.
  • Have a non-electrical source of heating, cooking, and lighting (e.g. gas heater, BBQ, torches and batteries).
  • If you are medically dependent on power, ensure you have an emergency plan. Click here for more information.
  • If you have a generator, make sure you know how to use it safely - never connect generators directly to the mains, and never use it indoors. Check out our fact sheet for more information.
  • Consider keeping a standard, non-cordless phone in the house, particularly if you live in an isolated area with limited cell phone reception.
  • Keep your refrigerator doors closed to help prevent food spoilage.
  • Check you know how to manually open automatic garage doors and security doors/ gates.
  • Unplug any sensitive equipment, such as computers, to prevent damage when the power is restored (you can also do this before a planned outage).
  • And finally, check on your neighbours. Particularly on vulnerable people in your community to make sure they are okay.

Prepare your business for power outages:
  • Check your terms and conditions with your electricity retailer - it will detail notification periods for planned electricity network outages and any compensation clauses.
  • Check your insurance provisions – how long does power need to be off before the policy covers you.
  • Have a good back up plan and ensure your staff are trained.
  • Consider the use of manual eftpos and credit card options.
  • Can your site be supplied by a generator – know your capacity requirements, connection options and generator hire contact details.
  • Have alternative locations for storage of perishable goods and freezer blankets.
  • Have back-up alternative locations to work from and phone diversions to mobiles contingency in place and when the power comes on understand what equipment needs resetting.