South Australians on lower incomes could save hundreds of dollars on their energy bills under the state government's bulk-buy power deal.
Premier Jay Weatherill says the government has negotiated concessions of up to $531 with Origin Energy, which was selected to provide a discount offer for about 168,000 households who currently receive concessions.
"We're providing real cost of living relief to those who need it most," Mr Weatherill said on Thursday.
While not compulsory, the scheme will include no late payment fees or paper bill fees, and Mr Weatherill said the government will write to eligible households encouraging them to sign up.
"We've negotiated this on their behalf to get a better deal, and make it as easy as possible for people take up the offer," Mr Weatherill said.
Origin Energy's executive general manager for retail said it's their "deepest discount" and will offer relief to customers who need it most.
It is an 18 per cent ongoing discount off usage charges and fixed charges, he said.
"This is our deepest discount that is available at the moment, this is going to make sure customers remain on the deepest discount," Mr Briskin said.
Opposition Leader Steven Marshall said while Origin Energy should be congratulated for their offer, the government was not doing enough to drive down prices for all South Australians.
"The big question is, what about the rest of the mums and dads and small business owners," Mr Marshall told ABC radio.