The $180 million Torrens Island battery, announced in August, will be delivered to energy giant AGL by Finnish technology company Wärtsilä. The big battery will initially start out with a one-hour duration (250 MWh) but will be capable of expanding to up to four-hour duration in the future (1000 MWh).
While its size pales in comparison to recent big battery announcements, the project has drawn attention for its deployment of grid-forming technology and is expected to reveal much about the promising new technology’s capabilities.
AGL expects the battery to be fully operational by early 2023, initially operating in grid-following mode before switching over to become grid-forming once Australia has finalized the new technology’s regulatory landscape.
The Torrens Island big battery will be the first in AGL’s national roll-out of 850 MW of grid-scale batteries. Rather poetically, the renewable project will be built at the site of AGL’s Torrens Island gas plant, just north of Adelaide in South Australia, and marks the first step in transitioning the fossil fuel site into the clean Torrens Island Energy Hub.
Grid-forming vs. grid-following
The Torrens Island battery will use over 100 inverters with grid-forming capabilities supplied from German-headquartered company SMA. SMA Australia’s Director of Large-Scale & Project Solutions Josh Birmingham told pv magazine Australia in August that trialling the technology at this scale “hasn’t been done before anywhere in the world.”
Traditionally inverters operate in what’s called grid-following mode, meaning their output synchronizes to the grid’s voltage waveform. ‘Grid-forming’ inverters, however, set their own frequencies, making them capable of providing the grid with ‘virtual inertia.’