Exploring grid security in a high-renewables era

How can Australia ensure the reliability of its grid as the nation rapidly makes the transition to a renewable electricity supply?

This is a question being explored by the NSW Decarbonisation Innovation Hub’s Electrification and Energy Systems Network, UNSW Energy Institute and the University of Wollongong. Together, the institutions have released a white paper, ‘Securing Power Systems in the Renewable Revolution’, which sets out a roadmap for navigating the next phase of the transition.

The grid is already managing a high percentage of renewable sources. Renewable penetration has reached 70–80% at times, without compromising system security, and nationally, there are more than 4.3 million rooftop solar connections, alongside a growing battery ecosystem. However, operating a highly renewable grid at scale, across seasons and under extreme conditions introduces new uncertainties.

The white paper identifies critical technical, regulatory and economic issues that must be addressed to ensure grid security.

“We’re moving from a system governed by physical properties to one controlled by software and power electronics,” said UNSW Energy Institute Industry Professor of Practice Mark Twidell, a white paper co-author. “That’s effectively an analog-to-digital transformation of the network.”

The system increasingly relies on inverters to convert renewable energy into grid-ready power. They are fast and flexible, but respond differently from traditional generators during disruptions.

“The main risk isn’t normal day-to-day operation,” Twidell explained. “It’s how inverters respond during faults and disturbances, and whether existing protection systems can continue to operate reliably when those responses change.

“The white paper calls for closer industry collaboration to harness existing data to understand inverter behaviour and plan ahead.”

A key concern is maintaining the grid’s ‘heartbeat’: the steady frequency that keeps electricity stable, without traditional generators.

“At some point we have to ask whether we’re still connecting new things to a legacy grid, or whether the new things are the grid,” said co-author Ty Christopher, Director of the Energy Futures Network at the University of Wollongong.

“We’re trying to manage a 21st-century grid with 20th-century regulation,” he added. “Those rules were written for a system that simply no longer exists.”

The white paper sets out a national approach to electrification built on partnerships between industry, academia and government. It seeks to address the immediate, high-stakes challenges, while also establishing a framework to resolve longer-term strategic issues that affect a wide range of stakeholders.

Its ultimate purpose is to provide a shared evidence base and clear priorities for those shaping the energy transformation.

“With the Australian Energy Market Operator last year highlighting emerging risks to system security, we need to quickly answer the unresolved questions in this paper to support the rapid rollout of renewables,” said Dani Alexander, interim CEO of the NSW Decarbonisation Innovation Hub and CEO of the UNSW Energy Institute.

“With early investment and a national approach, I strongly believe that our homegrown ingenuity can solve these challenges to secure our energy future.”

The report is available for download here.

Image credit: iStock.com/davidf