2017 South Australia Heatwave
What Happened
On one of the hottest days in 80 years, air conditioners across South Australia pushed electricity demand to extreme levels -- far beyond what forecasters predicted. Wind generation collapsed to just 96 MW (a fraction of what was expected), and the state's largest gas plant was sitting idle because its owner found it more profitable to sell gas on the open market. (continue below)
The grid operator ordered a controlled disconnection of 100 MW of load to prevent a total collapse. But a software error at the local utility tripled the cut -- 300 MW was shed, blacking out over 90,000 homes for up to 37 minutes.
Coming just five months after a statewide blackout that left 1.7 million people without power, the heatwave failure triggered a political crisis. The state government responded by commissioning what became the Hornsdale Power Reserve -- the Tesla Big Battery.
Timeline
Root Cause
Extreme heat met structural grid weakness. Demand forecasts failed badly. Wind generation collapsed. The largest gas plant was mothballed for profit. And when controlled load shedding was ordered, a software error at the distribution utility cut three times more homes than necessary. The grid had no flexible, distributed resources to bridge the gap.