A key renewable energy policy of the former South Australian government that was designed to help more people access home energy storage systems will be axed in Thursday's state budget.

The Home Battery Scheme was a commitment former premier Steven Marshall took to the 2018 election and rolled out once the Liberal Party was in office.

It was hoped the program, which at first offered a $6,000 subsidy that was later wound back to $2,000, would be taken up by 40,000 home owners.

Freshly reinstalled Energy Minister Tom Koutsantonis said the take-up was less than half that amount and was one of the reasons why the new government had opted to kill the program off in Labor's first budget since its election win in March.

"They [the former government] thought that by diminishing the subsidy it would increase the uptake of batteries," Mr Koutsantonis said.

"So 'we'll pay you less than we used to and batteries are more expensive now, therefore there'll be a high uptake of batteries'. It just didn't work."

Solar panel program also axed

A second program – Switch for Solar – will also be scrapped.

It was designed to allow eligible concession holders to exchange 10 years of their energy and cost of living concession for a solar system installed with no up-front cost.

But Mr Koutsantonis described the program as "a scam" and he was glad he "killed it".

"Taking concessions off elderly people is wrong. You shouldn't do it."

Cutting the two programs is expected to deliver a saving to taxpayers of $19 million.

Opposition and Greens lash decision

Opposition Leader David Speirs slammed the decision to scrap both programs, accusing the Labor government of being more interested in "empty gesture and symbolic rhetoric" rather than helping households transition to renewable energy.

"On top of this, these two programs contribute to lower cost of living at a time when many South Australians, particularly those living on concessions, are fearful of soaring electricity prices which we know are on the way."

Greens MLC Robert Simms was equally critical of the move.

"At this time of climate crisis, Labor should be supporting and enhancing programs like these that are designed to reduce carbon emissions," Mr Simms said.

"Axing these programs might deliver the new government some budget savings, but this decision will come at a huge cost to our environment. South Australians will be dismayed by this short-sighted thinking."

Conservation Council SA chief executive Craig Wilkins said the axing of the Home Battery Scheme came as a shock.

"If it is just about cost-saving, then it is very disappointing in the wake of the government's declaration of a climate emergency, because we know the shift to clean energy is an essential part of that response to an emergency," he said.

"South Australia is genuinely a global leader in renewable energy and that has been built on the back of programs such as the ones that are being scrapped."

Mr Koutsantonis said the government was focusing on renewable, grid-scale projects to help get power prices down for all energy users.