Households will be an average $2 a week better off under a reinvention of Australia's energy and emissions policy - and the Turnbull government has refused to guarantee even those meagre savings.
It emerged on Tuesday that the savings could start as low as $25 a year, or 50?? a week.
Despite pitching the policy as a salve to the hip pockets of price-weary power consumers, the government also concedes that the predicted cost saving was based on preliminary analysis, and detailed modelling has not yet been carried out.
The government on Tuesday sought to reset the national energy debate by announcing energy companies will be forced to meet mandated standards of reliability and emissions reduction, which would reduce the risk of blackouts and drive prices down.
Polls show voters are deeply concerned about soaring power bills, and the government's ability to address the problem is a key element on which the policy will be judged.
Mr Turnbull described the measure as a "game-changer ... that will ensure that we have affordable power".
"It provides investor certainty, which the market has been crying out for for a long time. It reduces volatility, which, of course, has been driving up prices," Mr Turnbull said.
Known as the national energy guarantee, the policy is based on a unanimous recommendation by the independent Energy Security Board, chaired by Dr Kerry Schott.
The board advised the government that the guarantee could cut residential bills by an average $100-$115 a year in the decade to 2030.
Wholesale prices were expected to drop by up to 25 per cent a year over the same period.
Australian Energy Market Commission chair John Pierce on Tuesday told Sky News that under other modelling scenarios, households would save just $25 a year in 2020 - or 50?? a week.
The annual household saving spruiked by the government is greater than the $90 predicted under the clean energy target recommended by Chief Scientist Alan Finkel - the prospect of which the government has abandoned.
However Mr Turnbull on Tuesday repeatedly refused to guarantee the price saving would be achieved.
He referred inquiries to Mr Pierce, a member of the advisory board who said the figures were based on "analysis and modelling of the market and the alternative schemes that we've looked at in the past".
Mr Pierce said the board would undertake "detailed analysis and modelling" of the proposal ahead of a November meeting of the Council of Australian Governments to provide "firmer estimates of those price effects".
He said the policy would drive down household bills in three ways.
The measures would end policy uncertainty, leading to increased investment, and hence, electricity supply.
The mechanism would also use existing market contracts to find a more efficient mix between dispatchable and low emissions energy, and competition would be improved because energy retailers would enter contracts with the lowest-cost energy providers.
Labor's energy and climate change spokesman Mark Butler on Tuesday said the government was unwilling to guarantee price savings to households and had "confirmed no modelling has been undertaken".
"At best it would appear that the broad analysis that has been undertaken would involve a 50?? per week saving for households in three years time, perhaps rising to as much as $2 a week."
"It's now incumbent on Malcolm Turnbull to release some real detail about this policy so we can all understand what the impact would be," Mr Butler said.
