Aluminum is one thing. Another is electrowinning iron which unlike Hall-Héroult is a wet electrolytic process. One assume you could stop the process indefinitely. And iron takes a lot less energy than aluminum. Capital cost are probably really low as well.
At residential rates the cost is a few hundred a ton for energy. So not economic vs carbon reduction. But if you could get the energy for nearly free. It would be.
At residential rates the cost is a few hundred a ton for energy. So not economic vs carbon reduction. But if you could get the energy for nearly free. It would be.