Tesla is set to follow up the success of its giant lithium-ion battery in South Australia with another huge project in the state.

Just over a month after the 100 MW Hornsdale Power Reserve – the world’s largest grid-scale battery storage system – came online, South Australian premier Jay Weatherill has signed a deal with Tesla for a 50,000-rooftop virtual solar PV plant with battery storage.

Plans include a trial installation of 1100 5-kW PV systems with 13.5 kWh Powerwall batteries (pictured) on public housing properties. If all goes well, 24,000 additional properties owned by the Housing SA trust are planned to join the scheme and, after mid-2019, it is planned to open up to the public and to include up to 50,000 properties by 2022. A registration of interest has already been opened for those wanting to participate. 

The state government said it will soon release a tender for a retailer to deliver the scheme, with a preference for bringing a new player into the market.

South Australia will help fund the AUD800m ($629m) project with an AUD2m grant and an AUD30m loan from its Renewable Technology Fund, with the rest funded through electricity sales. Participants will receive PV panels and batteries for free, and the government estimates their potential savings at around 30 per cent off current energy bills. 

In a statement, Tesla said that “at key moments” the virtual power plant “could provide as much capacity as a large gas turbine or coal power plant”.  In concrete terms, with all 50,000 rooftop systems included, the project could produce up to 250 MW, or around 20 per cent of South Australia’s daily energy demand.  

“My government has already delivered the world’s biggest battery, now we will deliver the world’s largest virtual power plant,” Weatherill said. “We will use people’s homes as a way to generate energy for the South Australian grid, with participating households benefiting with significant savings in their energy bills.”