A huge $1bn solar farm and battery project will be built and ready to operate in South Australia’s Riverland region by the end of the year.

The battery storage developer Lyon Group says the system will be the biggest of its kind in the world, boasting 3.4m solar panels and 1.1m batteries.

The company says construction will start in months and the project will be built whatever the outcome of the SA government’s tender for a large battery to store renewable energy.

A Lyon Group partner, David Green, says the system, financed by investors and built on privately owned scrubland in Morgan, will be a “significant stimulus” for South Australia.

“The combination of the solar and the battery will significantly enhance the capacity available in the South Australian market,” he said.

Green said the project, along with a similar one it plans to build near Roxby Downs, would have gone ahead whether or not Port Augusta’s Northern power station had closed in 2016.

“We see the inevitability of the need to have large-scale solar and integrated batteries as part of any move to decarbonise,” Green said. “Any short-term decisions are only what I would call noise in the process.”

The premier, Jay Weatherill, commended the Lyon Group for the Riverland initiative, which will enable 330MW of power generation and at least 100MW of storage. “Projects of this sort, renewable energy projects, represent the future,” he said.

The premier said the company was among several to express interest in building a 100MW battery as part of the South Australia government’s power plan announced this month, to be financed by a new $150m renewable technology fund.

Weatherill said the government would consider the bidders over the coming weeks.