Australian grid operator warns that accelerating data center expansion could push electricity grid capacity to limits in key regions by 2033.

Transgrid's 330-kilovolt network in western Sydney will be largely at capacity by 2033 due to a surge in data centre connections, the grid operator has warned. With 1.5 gigawatts of new data centres already under contract, the network is approaching its limits as demand has shifted dramatically from historical patterns.

"Data centre demand is now at significant scale and pace, with enquiries concentrated towards Western Sydney," Transgrid said in a mid-June letter to connection applicants. The operator reported an "unprecedented increase" in enquiries for large-scale electricity loads in the region. "More than 8 GW of prospective data centre load is currently in advanced discussions with Transgrid regarding potential connection to the transmission network. To put that into perspective, the average daily demand for electricity in New South Wales typically ranges between 7.5 GW and 10 GW."

While the committed 1.5 GW can be accommodated within the current network, future connections will likely face constraints.

The broader issue extends well beyond western Sydney. As Infraseek noted, the National Electricity Market's open access framework was designed in an era of large central generation and smaller, consistent loads. "Current NEM Rules provide little philosophy on how a finite amount of capacity should be shared once gigawatt-scale loads begin arriving together," the analysis stated. Data centre developers lack visibility into remaining network capacity and how it is being allocated, creating what Infraseek termed a "logjam of loads"—a parallel to the "Rhombus of Regret" experienced by renewable generators in north-west Victoria years earlier.

International grid operators are already grappling with similar pressures. The United States' PJM, Texas's ERCOT, and operators in Finland, the UK and Ireland have implemented various measures: Ireland imposed a multi-year moratorium on new Dublin data centres, Great Britain reformed its connection queue based on readiness, and ERCOT introduced batch study processes.

Transgrid's approach allows data centres to connect but requires them to fund network augmentations upfront if they trigger the need or expect to benefit from additional capacity, regardless of whether they connect at transmission or distribution level—subject to anticipated regulatory changes at the distribution level.