The Gannawarra solar and energy storage project near Kerang in western Victoria has had its official launch on Friday, to mark the largest pairing of a solar farm and a grid-scale battery system in Australia.

State energy minister Lily D’Ambrosio officially anointed the landmark project, which has combined 60MW of PV panels and a 25MW/50MWh battery system – Tesla’s second-biggest battery in the country so far.

The official opening of the Gannawarra project – which is co-owned by Wirsol (94.9%) and Edify Energy (5.1%) – comes some seven months after its November completion, when the combined solar and battery system successfully passed all commissioning tests.

It has been a key energy investment for the Labor Andrews government, which tipped $25 million into both Gannawarra and the Ballarat energy storage system in a bid to address “known stress points” in the state’s electricity network.

The Australian Renewable Energy Agency also put in $25 million to co-fund the Victorian energy storage projects, with close to $20 million invested from private equity.

Crucially, both batteries were up and running in time for summer 2018/19 – the $35 million Gannawarra has been since been credited with providing “invaluable power” during the extreme heat events of late January, by exporting 80 megawatt-hours of stored energy to the grid.

“Big batteries help to stabilise our power grid and provide much-needed backup power – which is vital to maintaining a reliable and affordable energy supply for Victoria,” minister D’Ambrosio said.

“By investing in renewable energy and storage technology, we are continuing to modernise our electricity grid, strengthen our energy security and deliver real action on climate change.”

Gannawarra has also sealed an energy off-take deal with EnergyAustralia, and a first-of-a-kind commercial services agreement with the utility.