icon-electricity Network restoration during significant weather events

  • Project Released: 12 Dec 2016
  • Project Closes: 23 Jun 2017
  • Contact: Natasha Cheshire


South Australia experienced a state-wide power system outage on 28 September 2016 and a major distribution outage on 27-28 December.

The Essential Services Commission has reviewed the performance of the transmission network operator, ElectraNet, and the distribution network operator, SA Power Networks, to determine whether they complied with the conditions of their licences (granted under the Electricity Act 1996) before, during and after these events. 

The full reports can be accessed below. The following sets out the key findings from each review, as well as the background to the two events and related projects. 



Current status is Final

  • Initiate
  • Final



South Australia experienced sustained rain and storm activity in the latter half of 2016, with particularly severe weather events on 28 September and 27-28 December. This gave rise to significant network outages and a substantial loss of electricity supply. 

The scale and impact of the events, in terms of network damage and customer impact, far exceeded anything experienced in South Australia before. 

  • On 28 September, a severe thunderstorm and tornados in the northern part of the State destroyed three transmission lines and set off a chain of events that led to the state-wide power system outage.
  • A major storm that commenced around 9pm on 28 December lasted for about 25 hours, with strong winds and heavy rain damaging homes, land, trees, roads and infrastructure. Electricity supply was interrupted to 182,540 customers (approximately 1 in 5 across the State).

The Commission initiated two reviews to understand the course of events and the operational response and actions, and to identify opportunities for improvements in customer outcomes.

As the relevant licensing authority, and consistent with its general powers and functions under the Essential Services Commission Act 2002, the Commission has compliance and enforcement powers in relation to the performance of licensees. 

Key messages: review of 28 September 2016 state-wide power system outage 

  • For the first time, severe weather gave rise to an emergency condition under the Electricity Transmission Code. In these areas, ElectraNet was required to use best endeavours to restore power, rather than meeting specific service standards. 
  • Notwithstanding the significant impact on customers, the information available suggests that, overall, ElectraNet remained compliant with the conditions of its licence and the Electricity Transmission Code. However, the Commission has identified areas for improvement, to promote the long-term interests of consumers with regard to the price, reliability and quality of essential services.
  • The outage has highlighted additional risks in operating the generation support at Port Lincoln.  As a result, there are opportunities for improvement in terms of restart procedures, clarification of Electricity Transmission Code requirements, maintenance and transparency of generation support availability.
  • Further, the Commission has requested additional information from ElectraNet on its risk management system and has required a compliance audit on the risk management portion of its Safety, Reliability, Maintenance and Technical Management Plan. 

Key messages: review of 27-28 December 2016 significant distribution outage

  • The number and duration of interruptions triggered the Major Event Day (MED) framework in the Electricity Distribution Code. This applies where customers experience an average interruption of six minutes or more (per the international standard). In this instance, the average interruption was 187.2 minutes. On days classified as a MED, SA Power Networks must restore supply as soon as practicable, rather than meeting specific service standards.
  • Having reviewed this matter in detail, the Commission has found that, overall, SA Power Networks did not breach either the reliability or the customer service regulatory standards imposed on it by the Commission. However, improvements can be made regarding the provision of accurate restoration times during severe weather events.
  • SA Power Networks has acknowledged and accepted that the multiple messages regarding predicted restoration times during the event was at times confusing. In response, it has implemented corrective action, immediate and longer-term, to mitigate the reoccurrence of erroneous customer information.

 Related projects

  • At the request of the Treasurer, the Commission also is examining prudent and efficient options for improving the reliability and quality of electricity supply on the Eyre Peninsula. A draft report was submitted in May 2017, with a public consultation to be held during June and July. The final report will be submitted by 6 October 2017. 
  • Subsequent to the December event, the Minister for Mineral Resources and Energy requested the Commission to investigate whether payments to customers under the GSL scheme should be increased to households affected by power outages longer than 48 hours. The Commission will release an Issues Paper on the structure of the GSL scheme to seek the views of stakeholders and the community. The Issues Paper and information on how to make a submission will be available on the Commission’s website by the end of July.