2 Case study – South Australian black system event

2 Case study –

South Australian black system event

People become used to reliable services and have little cause to stop to think about all the interdependent systems which function together so that, for instance, the traffic lights guide their commute out of the central business district, petrol is pumped into their car, and money can be paid with the tap of a card.

This chapter is a short case study on the South Australia black system event which demonstrated how disruption to the delivery of one service – electricity supply in this case – can cascade through infrastructure networks to affect the delivery of many other services. This case study serves as a reminder of the need, in a modern society, for government and industry to work together to manage risks and build resilience.

2.1 Interdependencies

In 2016 South Australia experienced a winter of extreme weather with flood events. Severe weather was forecast for and arrived on 28 September 2016. According to the Australian Energy Market Operator, tornadoes damaged electricity transmission lines, faults grew, and automatic mechanisms acted to protect assets.6 These factors led to an imbalance between supply and demand which caused a loss of electricity supply to South Australia. Eight hundred and fifty thousand customers lost electricity supply, affecting households, businesses, transport, community services and major industries. The review by Burns, Adams and Buckley7 includes a sobering reminder of the dependence on electricity:

Electricity is, with few exceptions, integral to all our systems, needs and requirements as a modern society. The loss of power quickly impacts upon essential services, critical infrastructure and the very fabric of our society. Electrical power is often taken for granted but modern society (at all levels) is heavily reliant and dependent on it.

While electrical power was restored to Adelaide within several hours, large areas of South Australia remained without power for several days. The review describes specific effects and consequences of the black system event in some detail and demonstrates the interdependencies between services. It was about an hour before the end of normal business hours on a Wednesday afternoon when the power went out. Transport signals and many traffic lights stopped working and the Traffic Management Centre lost the ability to observe and control intersections. As a result, police personnel were used to control key intersections in the difficult weather conditions.

6 Black System South Australia 28 September 2016, published March 2017 7 Final Report of the Independent Review of the Extreme Weather Event South Australia 28 September-5 October 2016, January 2017

Electric trains and trams stopped on the rails. Extraction fans in the city's main train station failed meaning that diesel trains could not be used as a redundancy measure to move passengers. Buses were used to move commuters.

Issues with refuelling added to the difficulty. Many service stations had generator back-up to provide electricity for their shopfronts, but few could power the pumps which bring fuel up from underground tanks to customers’ vehicles. The review notes that customers’ ability to pay for fuel at stations which could pump was an issue given automatic teller machines, card services and electronic payment options were rendered unavailable. The loss of electricity supply meant that South Australia’s main fuel distribution point did not have the capacity to pump fuel. The review notes that an enduring power outage would quickly impact the whole fuel supply network leading to shortage. The review commented on gaps in the business continuity planning of government agencies, businesses and individuals. The review outlined that the extended loss of power caused mobile and landline telecommunication networks to fail or at best provide an intermittent and therefore unreliable network. It describes the impact on police, ambulance, fire and rescue services including impacts to operational communication, control centres and community access to emergency call-taking and dispatch. It also describes effects on emergency broadcasting of public information. The cascading disruption from the electricity supply to telecommunications flowed further. For example, where the electricity outage was prolonged, food retailers also lost the ability to offer electronic payments, cash out transactions, and send or receive orders of grocery items, perishables and frozen food.

The chamber of commerce and industry for South Australia surveyed members of the business community soon after the event. From the results it estimated the cost of the black system event on South Australian businesses at $367 million, including an estimated $115 million impact on major industrial businesses.

The review explains that the water authority’s business continuity planning arrangements ensured the supply of water and sewerage services, therefore avoiding public health issues. In Port Lincoln, where the electricity outage lasted longer than it did in Adelaide, a rotational system of back-up generation was implemented at key sites, ensuring that town sewerage did not become a major issue. The review notes that overall, both metropolitan and country hospitals generally stood up well during the black system event. However, the review also discusses specific instances where pharmacies and aged care facilities were challenged and mentions losses at a private fertility clinic. The South Australian black system event is a real-life scenario of how a disruption to just one essential service, electricity, has the capacity to result in significant flow-on impacts on the delivery of other services, resulting in consequences for the community on a statewide scale.

It also serves as an example of where a resilience building activity, in this case business continuity planning by a water authority, can help to mitigate consequences to the community.

Image: AAP Image/David Mariuz