This report illustrates the technical challenges of the changing generation mix and the need for these to be managed with the support of efficient and effective regulatory and market mechanisms that work together for the least cost and long-term interest of consumers.

This is AEMO’s final report into the Black System in South Australia (SA) on 28 September 2016. It contains all the information previously published, and highlighted information that has been updated or added since the previous report. This report is divided into the following sections: 

• Pre-event – the status of the power system in SA prior to the Black System on 28 September 2016 and a summary of NER provisions related to AEMO pre-event decisions on system security. 
• The events resulting in the Black System – the sequence of events on the power system that occurred in the SA region of the National Electricity Market (NEM) in the 87 seconds before system shutdown at 16:18:16. 
• Restoration – the sequence of steps taken to restore normal power supply to all SA electricity consumers. 
• System Restart Ancillary Services (SRAS) – the sequence of events and actions taken relating to provision of SRAS in SA during the Black System. 
• Market suspension and subsequent operation – a summary of the provisions in the NER related to market suspension in the NEM, and of the sequence of events from the system shutdown to lifting of market suspension on 11 October 2016 at 2230 hrs. 
• Recommendations – for action proposed by AEMO as a result of this investigation. 
• Next Steps – an outline of the broader work being undertaken by AEMO to address the challenges to power system security and reliability posed by the changing nature of the power system