Police arrested four climate change activists on June 9 after their protest stopped production for five hours at Australia's largest aluminium smelter at Tomago, near Newcastle.
The two smelters in the Hunter region, at Kurri Kurri and Tomago, consume about 15% of NSW's electricity. But huge government subsidies mean their energy costs per megawatt are one-sixth of that paid by households.
If the Rudd government's planned Carbon Pollution Reduction Scheme becomes law, smelters like Tomago will have 90% of their carbon credits paid for by the public.
Protest organising group Rising Tide called on the federal government to use the money now spent on subsidising polluting coal-fired smelters on renewable energy projects instead.