South Australia Spot Electricity Prices Hit Cap Twice in Wind Lull

Spot electricity prices in South Australia reached the market price cap of $20,300 per megawatt-hour on the evening of 22 June 2026 and again the following morning, Abc reported. The spikes occurred during a four-day wind lull that ended 25 June. Wind generation fell to a rolling-average output of 124 MW from the state's 2,800 MW of installed capacity, an availability of 4.5 percent.

That figure was lower than the two previous worst recorded lulls, which showed capacity factors of 5.6 percent and 6.6 percent. The recent period was the lowest wind-output interval recorded in the state at least since 2019. On the evening of 18 June the state had met 100 percent of demand from wind and exported surplus power.

Overnight on 21 June wind supplied only 1 percent of demand. Virtually all remaining supply came from gas-fired generation or imports from Victoria, where coal dominated output. The average wholesale price in South Australia for the first quarter of 2026 was $88 per megawatt-hour.

High-voltage transmission constraints caused the state to export power to Victoria even while local prices were at the cap. Many batteries discharged heavily on the afternoon and early evening of 22 June, leaving roughly half able to respond to the first price spike.

Almost no battery capacity responded to the second spike on 23 June, and some batteries were charging at prices up to $10,000 per megawatt-hour.

South Australia plans to more than double large-scale battery capacity to 2,500 MW, enough to power about 300,000 homes for eight hours. The government also intends to develop long-duration storage and increase gas supply. Solar generation remained solid throughout the lull.