South Australia is leading the way with the implementation of sustainable energy solutions and has rapidly adopted renewable energy generation sources. As more of these power sources, such as wind and solar PV are connected to the grid, the share of aging traditional synchronous sources, like gas-fired units, is decreasing.
This rapid shift in energy generation sources has the potential to impact system strength and create a shortfall because the way in which renewable sources generate and connect to the grid differs from traditional sources, which makes it more difficult to respond to fluctuations in supply and demand.
While the adoption of more sustainable power sources is important for Australia’s future, having a secure power supply for South Australians is equally important, which requires both system strength and inertia to be achieved.
System strength refers to the power system’s ability to manage changes in supply and demand while maintaining a stable voltage. Inertia is the power system’s ability to manage fluctuations in supply and demand while maintaining a stable system frequency. Our network operates at a frequency between 49.85 and 50.15 Hz; if the system goes too far out of this narrow range, the generators can start to disconnect in trying to protect themselves from damage, which can lead to serious interruption of supply or even ‘blackouts’. The system needs to be carefully managed to balance generation coming into the system and demand going out so that the frequency does not go outside the set range.
After investigating various options to improve system strength, ElectraNet has received regulatory approval to install four synchronous condensers on the South Australian network, with two being installed at the Robertstown Substation, 130km north of Adelaide and an additional two being installed at the Davenport Substation just outside Port Augusta.
A synchronous condenser operates to ensure the power system has the minimum levels of both system strength and inertia and therefore stabilises the system, preventing supply interruptions. A synchronous condenser is a sizable machine that works in a similar way to a large electric motor, where it has a large freely spinning shaft, electromechanically coupled to the grid, and can manage changes in system strength, inertia and voltage. They can be equivalent in size to three to four sedans parked end-to-end, as high as an AFL goal post, and weigh more than two Boeing 737 planes.
Enerven will be undertaking the design, construction, and commissioning of the works required to install synchronous condensers at the Robertstown substation. This will mean the existing Robertstown substation will be augmented to support the new Synchronous Condensers, extending the substation to include two new parameters, one for each Synchronous Condenser.
Enerven’s team has unparalleled experience with complex brownfield infrastructure projects in South Australia and will leverage their comprehensive knowledge and understanding of ElectraNet’s infrastructure to deliver this project successfully. The project is set to support around 100 South Australian jobs and will call upon local contractors from the region to complete the works.
Further to strengthening the grid, from the point of commissioning, the synchronous condensers are also estimated to deliver a net saving to customers equivalent to $3-$5 per year on a typical residential electricity bill, and correspondingly more for larger customers. This is due to being able to avoid increasing costs incurred by AEMO in directing and compensating existing gas-fired generators to manage system strength shortfalls.