Alinta Energy said it was “deeply concerned” about the ability of states to opt out of the Energy Security Board’s proposed capacity mechanism and exclude coal and gas, saying it could undermine the new system and affect future investment.

As big energy companies remain divided over the final design of the capacity mechanism – which energy ministers want to be introduced by 2025 – there is growing opposition to the ministerial decree that states can pick and choose what parts of the scheme they sign up for.