Alcoa chief executive Bill Oplinger says there is no plan to shut Victoria’s Portland aluminium smelter within the next decade but warns batteries are unlikely to be the “firming” solution that solves the smelter’s increasing reliance on variable energy sources such as wind and solar.

Oplinger said Australia needed to decide how it would backstop intermittent renewables, adding that Alcoa would be a big user of gas for a long time to come, and that nuclear power could also support wind and solar.