Labor leader Bill Shorten has taken his election campaign to Adelaide, where he will promise to unlock the renewable energy potential of the Spencer Gulf if he wins the election.

Mr Shorten has pledged to make the area a renewable energy zone, which will see it benefit from a $5 billion Labor fund.

“We still have huge untapped potential in the Spencer Gulf region,” he said on Wednesday.

“Unlocking this potential will supply cheaper, cleaner, renewable energy, as well as providing a vital source of regional employment.”

Mr Shorten expects the plan to breathe life back into towns around the Spencer Gulf and Gulf St Vincent regions.

The Labor leader is in the South Australian capital after spending two days in Perth, where he made the same renewable energy pledge for the South West region of WA.

While in Perth Mr Shorten also promised to make it easier for schools to get solar panels, $105 million for defence and $75 million for mining exploration.

He has had to fend off questions regarding his plan to top up the pay of childcare workers, insisting it’s a “special solution” which will only apply to that sector.

“We have other mechanisms to help other industries,” he told reporters in Perth.

But the coalition has warned Labor has opened up a hornet’s nest where other sectors would come knocking on Mr Shorten’s door.

“Bill Shorten has created a circumstance where people now say, ‘Well, what about us? Why don’t we get the same sort of deal?’, coalition campaign spokesman Simon Birmingham said.

Mr Shorten is also steering the focus away from the cost of his emissions reduction policies by saying they are an investment for the future.

But he says it’s impossible to put a price on his 45 per cent emissions reduction plan as businesses will choose how to reduce their pollution.

Mr Shorten has been on the attack against the coalition’s preference deal with Clive Palmer, warning workers in Perth not to vote for “crazy minor parties”.

But he is expected to face more questions over the controversial billionaire and preferences ahead of the May 18 election.

Labor has put Mr Palmer’s party above the Liberals on their how-to-vote cards in 87 lower house seats, including putting it second in two Tasmanian seats.