Electric arc furnaces (EAFs) are becoming more ubiquitous, as they allow steel production using less energy and releasing fewer greenhouse gases than the traditional blast furnaces. This could be an interesting alternative source of Steel Bars in the late game (after unlocking Industry).

EAFs cannot produce steel directly from iron ore (iron concentrate) but instead typically use scrap metal or pre-reduced iron from a bloomery. This could give us a recipe like 4 Iron Bars + 2 Quicklime + 4 Charcoal Powder = 4 Steel Bars (improved by Modern Upgrades). While this recipe is more complicated, it is also cheaper, providing a late-game method for mass-producing Steel Bars/Rebar/Corrugated Steel for large construction projects.

The EAF could also have the ability to melt down broken tools/parts into Iron Bars, providing a late-game way to recycle them rather than throwing them in a landfill.