Tomago Aluminium chief Matt Howell supports the federal government's threat to intervene in the market and build a gas plant if it provides "like-for-like" power when AGL's Liddell coal-fired power plant shuts.

Mr Howell also applauded the decision by Queensland zinc refinery Sun Metals to commit to powering its entire operations with renewable electricity by 2040, but insisted it wasn't possible for Tamago's Hunter Valley aluminum smelter to follow suit.