Federal resources minister Josh Frydenberg says the South Australian energy plan will increase electricity prices in that state and threatens prices in Victoria, NSW and Tasmania.

He is seeking legal advice on whether the decision by SA to "go it alone" was in breach of the national rules that have "kept the system together for the last 20 years".

"Going it alone created SA's problems and going it alone won't fix SA's problems," Mr Frydenberg told reporters in Canberra.

"Now Labor is trying to fix its own mess. It is confusing and it is nonsense." Alex Ellinghausen

He said the measures announced on Tuesday – including $360 million for a new gas power plant, $150 million for battery storage and changes to put SA before the national electricity market – will only increase electricity prices.

"We established, some 20 years ago, a national electricity market in order to ensure that the lowest cost electricity was dispatched in five minute intervals," Mr Frydenberg said.