In New Zealand, because of our isolated system and reliance on hydro generation, the main risk to security of supply is low hydro lake levels.

While it’s the responsibility of the electricity industry to provide security of supply, it’s our responsibility to ensure that the regulatory environment promotes consumers benefiting from an efficient level of reliability (for example the cost of providing security of supply is appropriately traded off against the costs and risks associated with a loss of supply).

Transpower, as the system operator, has operational responsibility for providing information on all aspects of security of supply and managing supply emergencies. 

System Operator - Security of supply animation

In the event of a potential or actual security of supply risk (such as key hydro lakes falling to critical levels), the system operator will communicate the security situation to the public. The Authority's involvement during such an event, if called upon to do so, is to communicate the policy intent of the security of supply framework that the system operator is responsible for operating within.

Security of supply does not include reliability of supply to consumers arising from short-term causes, such as storms or earthquakes.

The quality of service provided by electricity lines businesses, including the reliability of that service, is regulated by the Commerce Commission.

Commerce Commission website