World’s Largest Grid Scale Storage Project in Australia
The Torrens Island battery is AGL Energy’s first grid-scale storage project. It will be built at the company’s gas plant, where it will continue to provide electricity as the fossil-fuel run turbines are retired.
The AUD 180 million ($131.8 million) battery isn’t Australia’s largest and only has one hour of storage (it is expected to expand to four hours). However, the project will be the largest in the world with grid-forming capacity, and will undoubtedly be observed within Australia and internationally.
The system, to be delivered by Wärtsilä, will initially operate in the usual grid-following mode, meaning that the output synchronizes to the grid’s voltage waveform. It will then be switched into the more novel grid-forming mode, making it capable of providing the grid with “virtual inertia.” System strength services and inertia have traditionally been the realm of spinning mass fossil-fuel driven turbines, but grid-forming projects hold promise as a clean substitute.
Their virtual inertia is provided by grid-forming inverters, which in this project will be provided by Germany’s SMA. Also known as virtual synchronous generation, the Australian Energy Market Operator (AEMO) recently identified grid-forming technology as a top priority because of the crucial role it expects the technology will play in the clean energy transition.
While large-scale demonstrations of grid-forming storage like Torrens Island are not yet in operation, Australia has already had some success with the technology on a smaller scale. Its triumphs include the 30 MW/8 MWh Dalrymple Battery Energy Storage System, which is currently the only source of virtual inertia in the National Electricity Market.
Storage systems with grid-forming inverters independently set their internal frequency and speed, making them able to form an islanded grid by generating a frequency reference. In other words, they can continue to provide power to the network if the main grid goes down – something systems without that technology cannot do.