Pipelines of liquid or gaseous fuels is pretty much always going to be the cheapest solution for energy transmission. This fact will inevitably lead to people investing in some kind of green chemical. If not hydrogen, then likely something made from hydrogen like ammonia or methanol.
It's not actually clear if transmission lines are cheaper. Ships and trains can carry a lot of mass. For an energy dense fuel, this can be cheaper. Then again, this idea needs you to carry things in both directions, both the iron and the iron oxide. That may doom this idea to being too expensive.
It's not actually clear if transmission lines are cheaper. Ships and trains can carry a lot of mass. For an energy dense fuel, this can be cheaper. Then again, this idea needs you to carry things in both directions, both the iron and the iron oxide. That may doom this idea to being too expensive.