Sixty thousand properties in South Australia were blacked out by mistake during last week's heatwave, a report into the incident has revealed, with the bungle blamed on a computer glitch.

At the height of the power supply crisis, when demand across SA hit record levels, the Australian Energy Market Operator directed SA Power Networks to shed 100 megawatts from the state’s electricity network. But a report released by AEMO on Wednesday found that 300 mw was cut instead, pulling the…