For renewable energy such as wind turbines and solar power inverters to help the grid withstand shocks, changes need to be made to the way the power system is managed.
Clean Energy Council director of energy transformation Tom Butler said the current rules governing the operation of Australia’s power system have inhibited renewable energy technologies from playing a more proactive role supporting the recovery process during unexpected shocks.
“While coal and gas power plants have traditionally provided inertia and system security services, many of Australia’s coal plants are now past the date where they were expected to retire. New wind, solar and storage technologies are ready to play a role in this transformation. But the market and its rules and regulations have to move with the times,” Butler says.
The problem is outlined in the white paper Arresting Frequency Changes in a Modern Electricity System, found at the CEC’s new Energy Security website.
The power system hums along at a frequency of 50Hz, Butler says, and major disturbances can push frequency rapidly up or down, threatening the security of the power system. Inertia acts to slow the rate of change of frequency when an event occurs.
“Unfortunately there is increasing evidence the safeguards we have in place for dealing with system shocks are not working effectively. The system relies heavily on inertia to stop rapid changes in frequency,” he says.
“A further concern is that the market operator doesn’t actually know how effectively our old fossil fuel generators will respond when a major shock occurs. This ultimately puts Australia’s energy security at risk and is something which has not occurred anywhere else in the world.”
Wind turbines and batteries have provided fast frequency response in other countries to supplement the inertia in the power system, he says.
The paper includes practical recommendations, such as:
- Establish appropriate standards for frequency conditions that apply to all technologies and focus on the speed and accuracy of their contribution to arresting the change in frequency following a disturbance.
- Accelerate trials of fast frequency response from inverter-based technologies to further prove this solution in the context of the NEM.
- Review legacy synchronous generators and undertake testing to demonstrate the performance and capability of the fleet under high rates of change of frequency.
- Undertake a detailed review of generator governor settings with an aim to refine the power system’s performance, while understanding and addressing the drivers that have resulted in a poorly tuned power system.