SA staves off rolling blackouts after huge Vic power outages

South Australia has averted rolling power blackouts despite a huge Victorian power station shutting down.

South Australia has averted rolling blackouts – manual electricity load shedding – despite an outage of one of the nation’s largest coal-fired power stations in Victoria.

SA’s electricity demand hovered close to supply for a short time after the unexpected shutdown of AGL Energy’s Loy Yang A, which went offline shortly after 1.30pm.

More than 500,000 Victorian homes and businesses were without power by 4pm as load shedding, or rolling blackouts, were triggered to protect power grid security and prevent long-term damage to infrastructure.

SA’s power grid is connected to Victoria through the Heywood Interconnector – essentially a high-capacity extension cord.

Officials at high-voltage network operator ElectraNet met on Tuesday afternoon with counterparts at the Australian Energy Market Operator to assess the situation.

“At this point in time we do not expect any issues with supply in South Australia,” an ElectraNet spokesman said at about 3.30pm.

Power had been restored to all Victorian customers affected by the “controlled disruption”, AEMO said in a statement issued at 5.25pm.

It said 90,000 customers had been affected by the load shedding, while about 500,000 customers remained without electricity due to high temperatures, strong winds and lightning damaging the power network.

A general view of the Loy Yang power plants as the sun rises in Traralgon, Australia. T (Photo by Asanka Ratnayake/Getty Images)

AGL issued a statement just after 5.15pm, saying work to restore Loy Yang generator units had started.

“Following today’s tripping of transmission lines that led to the unplanned outage, work is underway to return units back to service. This will take place over the next few hours in line with our safety and operational protocols, and as associated transmission line issues are resolved,” an AGL spokesman said.

In SA, load shedding outages last between 30-45 minutes and the number of affected suburbs depend on the amount of supply SA Power Networks, which operates the distribution network, is required to cut by the AEMO, which runs the national grid. The CBD, hospitals, prisons and other areas with critical infrastructure are exempt from the list, which is determined by the

Office of the Technical Regulator, responsible for overseeing energy and plumbing safety in South Australia.

The scale of load shedding depends on the shortfall in generation within the state, meaning it can also be called to a halt suddenly if the imbalance between consumption and supply is corrected.

The last time manual load shedding occurred in SA was February 2017, when power was cut to more than 90,000 homes and businesses after AEMO ordered a 100-megawatt supply cut.

Residents across Adelaide’s northwest are next on the blackout hit list if the energy operator orders load shedding to protect the struggling power system.

If load shedding was ordered, properties connected to the Woodville power substation would be first to cop a blackout of 45 minutes if distributor SA Power Networks was ordered by the AEMO to cut supply to keep the electricity grid stable.

Suburbs next on the hit list are Woodville Gardens, Wingfield, Pennington, Rosewater and Woodville. If further load shedding was required, residents in suburbs including St Clair, Cheltenham, Woodville North, Ridleyton, Brompton and Bowden would have their power cut next.