It took "one of the most significant severe thunderstorm outbreaks in recent decades", with seven tornadoes and a storm producing phenomenally damaging wind speeds, to bring down South Australia's power grid and cause a blackout in late September. Although the national electricity market operator and conservative commentators were quick to blame renewable energy, it's now clear that the entire network was at risk — and the blackout could have been lessened had precautionary steps been taken.
RenewEconomy reports on the Bureau of Meteorology's investigation into the 28 September thunderstorms, saying that a series of travelling localised tornadoes destroyed transmission lines and crumpled towers near Wilmington and Blyth in central South Australia — not any issue related to renewable energy. The wind speeds recorded are similar to those measured when Cyclone Tracy effectively leveled Darwin on Christmas Day in 1974.
A total of 22 towers being destroyed between Adelaide and northern South Australia caused a cascading power overload that caused the statewide blackout, starting at 3:48PM and lasting for several hours through the night. Despite the warnings of impending damaging storms from the BOM, Australia's AEMO continued to run the energy-transferring interconnector between South Australia and Victoria.
AEMO will submit a response to the Bureau of Meteorology's statements in its December report into the blackout. The energy market operator continued to run the inter-state interconnector at "near full capacity" until the blackout occurred, according to RenewEconomy, and then shifted blame onto South Australia's installed renewables — the state is the largest producer of wind energy in Australia.