Beginning on the afternoon of September 28, an extreme weather system struck the state of South Australia (SA), knocking out transmission lines interconnecting SA to neighboring Victoria and forcing a shutdown of wind generation due to sustained high winds. This loss of imported power from Victoria and the loss of significant wind capacity within SA resulted in a blackout at 4:18:16 local time that impacted the entire state of SA and its 1.7 million residents for more than 24 hours.
Key Details
- The extreme weather system featured hurricane-force winds and has been described as a “hundred-year storm”
- SA became coal free with the May 2016 shutdown of the 520-MW Port Augusta generating station
- Just prior to the blackout, SA was supplying 1,826 MWs of electricity with a generation mix consisting of:
- 48% wind generation
- 34% imports from Victoria via two interconnections
- 16% natural gas
- Minimal solar generation, due to the weather
- A confluence of factors between 4:16:46 and 4:18:16 local SA time caused the blackout, including:
- The destruction of 22 transmission towers leading to the loss of three 275-kV transmission lines in the northern part of the state isolating SA from all power being imported from Victoria
- The loss of 315 MWs of wind power or 21% of the state’s 1,484 MWs of total wind generation capacity. This shutdown was in accordance with design standards; the turbines were removed from service due to high sustained wind speeds
- In the wake of the blackout, the conversation quickly turned political. Though the conservative federal government has conceded that the event was caused by extreme weather, they are questioning whether SA’s heavy reliance on solar and wind-generated power has made its network less reliable. This stance was voiced by Australian Prime Minister Malcolm Turnbull who told reporters, ‟Energy security should always be the key priority. I regret to say that a number of the state Labor governments have over the years set priorities and renewable targets that are extremely aggressive, extremely unrealistic, and have paid little or no attention to energy security.”
- SA Premier Jay Weatherill quickly shot back at the prime minister telling reporters, ‟This was a weather event, this was not a renewable energy event.”
- Simon Emms, the executive director of ElectraNet, the company which operates SA electricity infrastructure said the blackout could not have been avoided given the weather conditions, “I’m not aware of any system in the world that could handle losing that much generation that quickly without going into a blackout.”
- The Australian Energy Market Operator’s (AEMO) preliminary report indicates, “…the event was triggered by extreme weather…”, and AEMO has stated that it will continue its investigation to identify the root cause of the event
- Given SA’s ambitious renewable goals (50% by 2030), developers are focused on bringing additional wind capacity online, which will exacerbate intermittency and balancing challenges. Wind generation comprises:
- All of the 225 MWs of committed capacity coming online
- 70% of the 2,935 MWs of proposed projects
Implications
This outage highlights the difficulty in planning and operating a grid using a supply set which includes a high percentage of intermittent resources and relies on imported power for balancing. Assumptions that inform contingency planning, storm preparedness, and outage recovery should account for a changing generation mix, the potential for more frequent “hundred-year storms”, and the availability of imported resources. While the final evaluation of the root cause and the electric system response is still pending, what is clear at this time is that outages and disruptions will quickly become politicized in areas where renewables are supplanting fossil generation.
Contributing Authors
Chris Sturgill, senior associate, ScottMadden
Eric Hanson, manager, ScottMadden
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