Transgrid has published its Project Assessment Draft Report (PADR), identifying the combination of solutions required to meet the needs of the New South Wales power system as the state transitions to renewable energy.

Transgrid conducted an Expression of Interest in 2023 which identified 100 possible non-network and network solutions to provide system strength to the New South Wales power system.

After reviewing, Transgrid published the PADR identifying the preferred portfolio of solutions.

The solutions are designed to maintain system security by creating a strong signal – much like a human heartbeat – to help the energy system ride out interruptions and avoid instability.

Transgrid Executive General Manager of Network, Marie Jordan, said, “Our power system is undergoing a high velocity transition. As coal retires and more renewables are connecting, we are facing unprecedented challenges to maintain the security and reliability of an increasingly complex system.

“We have a comprehensive System Security Roadmap in place and one of our key pillars is maintaining the strength of the system so it can operate effectively without coal.

“The release of this report is a big step forward in our planning to ensure the heartbeat of the grid stays strong throughout the rapid transition,” Ms Jordan said.

Transgrid is undertaking a Regulatory Investment Test for Transmission (RIT-T) process to identify the optimal combination of solutions required to meet the needs of the power system in the coming decade.

The PADR identified potential solutions, including:

Between eight and 14 synchronous condensers to replace system strength that comes from retiring coal assets and unlock additional renewable generation

Modifications to several synchronous hydro generators and a future compressed-air energy storage facility

Contracts with a range of existing hydro, gas and coal generators to ensure they can switch on or operate in synchronous condenser mode when needed

4.8GW of batteries with grid forming capability to support the stable operation of new renewable generators

“The future power system must be capable of operating at up to 100 per cent instantaneous renewable energy in the coming decade. To support the amount of wind, solar and hydro required we must invest in a diverse range of options to keep the system strong,” Ms Jordan said.

“As part of this process, we assessed more than 60 individual non-network solutions and 40 unique network solutions to meet requirements.

“There are so many moving pieces in our energy puzzle and no single solution can meet the need – in fact, dozens of solutions across New South Wales will be required at any one time to keep the system operating securely.”

Transgrid is the first transmission provider in Australia to launch a comprehensive program to safeguard system strength, which is necessary to support the Federal Government’s target of 82 per cent renewable generation by 2030.

“We are acting to ensure the lights stay on as we work to deliver the priority projects and investment to support the New South Wales and Federal Governments’ vision for a clean energy future,” Ms Jordan said.

“Currently our energy system relies on system strength produced by large spinning machines such as coal, gas and hydro generators – which provide a strong heartbeat to keep the grid stable so it can ride through disturbances.

“Renewable sources like wind and solar don’t have the same capabilities and need to follow a strong signal from the network, or they will disconnect, which is why we urgently need new sources of system strength.”