Natural gas or propane are not appropriate from my limited knowledge of chemistry. It is not just heat. Heat in itself does nothing productive for our purposes. We need electricity, i.e. the arc to break the chemical bonds in the ore. I believe the process involved might be similar to aluminum smelting, which also relies on large amounts of electricity.

Where there may be a saving grace is that I have read in the past of plans of harnessing some of the rivers in the north for hydro electricity.