The $4.9 billion HumeLink transmission project is shaping up as the first big test of governments’ will to progress difficult projects needed for the energy transition, says a key adviser to the NSW government.

Cameron O’Reilly, the lead author of an independent review into the state’s energy reliability and supply which recommended the extension of the Eraring coal generator, said the full benefits of several projects already under construction could not be delivered without the controversial HumeLink project, making it vital to the transition.