The model chosen by energy ministers to help fix transmission congestion on the grid from the influx of renewables was originally estimated to cost up to 30 times more than the connection fee model recommended by the Energy Security Board.

While renewable energy advocates welcomed the decision by energy ministers to proceed with work on a congestion relief market to connect new wind and solar projects to the grid, a preliminary assessment by the Australian Energy Market Operator last year showed it could cost more than $300 million to establish.