Household power prices in South Australia would fall by more than $300 a year under an energy plan outlined by the state opposition.
The eagerly awaited plan will spend $200 million on a greater connection to the national energy market and $150 million on battery storage.
Liberal leader Steven Marshall believes the state election next March will be a referendum on energy policy, and if he wins his $550 million plan will also dump the government's state-owned power plant.
He wants to give 40,000 homes battery storage to potentially reduce electricity use at times of peak demand which he says will help limit stress on the grid and lower the price of power.
In delivering his policy, Mr Marshall took a swipe at Premier Jay Weatherill for cosying up to Elon Musk during the construction of Tesla's lithium ion battery in Jamestown.
"We are going to back South Australians who want to take charge of their electricity generation and consumption," the opposition leader said.
"Our battery program will focus on South Australians, not celebrity billionaires."
Under the Liberal plan, the battery storage subsidy will be offered to home owners through a means-tested component yet to be detailed.
Average grants are likely to be about $2500.
Gifting the batteries to a portion of the community would help the entire state, opposition energy spokesman Dan van Holst Pellekaan said.
"Every single household and every single employer in South Australia will receive reduced electricity prices through reduced wholesale prices under our plan," he said.
The household saving of $302 per year was calculated by independent experts, but won't be fully realised until at least 2021.
Premier Jay Weatherill said the government's battery at Jamestown would reduce power bills by $50 immediately.
The premier said relying on extra energy from interconnection, essentially an "extension cord" from the eastern states, would also leave SA's access to power vulnerable.
"The fundamental issue with price and reliability is lack of generation on our side of the border," Mr Weatherill said.
"The South Australian plan that we put in place is about taking control of our energy future."
The South Australian Chamber of Mines and Energy said the Liberal energy plan was a balanced approach to energy reform and recognised the importance of gas generation to the market.
Conservation SA and the South Australian Council of Social Services questioned the lack of help for renters and low-income families.
