AEMO releases preliminary report into NSW market suspension on the 23rd March 2026

Yesterday, the AEMO released their preliminary report into the NSW market suspension that occurred on Monday 23rd March 2026.

Readers will recall that AEMO declared the NSW spot market suspended from 11:45 NEM time, with pricing shifting to the Market Suspension Schedule Pricing framework under the NER. The suspension was linked to issues with SCADA data, which limited AEMO’s ability to operate the market in the usual way. Once those systems were restored, AEMO resumed market operations later that evening (at 18:30 NEM time).

The executive summary of the preliminary report attributes the root cause of the SCADA disruption to an issue within Transgrid’s systems:

At approximately 1008 hrs on 23 March 2026, AEMO began to experience a loss of New South Wales supervisory control and data acquisition (SCADA) service due to an issue originating within Transgrid’s SCADA network. This initially resulted in a partial loss of SCADA service. At approximately 1108 hrs, the impact escalated to a complete loss of New South Wales SCADA service at AEMO. AEMO subsequently suspended the spot market in New South Wales from trading interval (TI) 1145 hrs to TI 1830 hrs on 23 March 2026.