The economic benefits of monitoring anode currents are likely to result from:
- Reduced greenhouse gas emissions as a consequence of minimizing anode effects. The value of this benefit will depend on local carbon trading opportunities/carbon taxes
- Increased production resulting from better balanced current distribution. Data from Alcoa have shown that pots operate at higher current efficiency if the currents vary little from anode to anode of a pot.
- Reduction of energy cost per ton of production due to increased CE.
- Operating benefits such as early detection of poorly set anodes, anode spikes and anode slips.
It is only possible to quantify these effects after consideration of individual plant cases. However for a representative plant producing 250,000 tons per year of aluminum, a 1% improvement in CE brings additional gross revenue of the order of $5 million/year at current LME prices. This is likely to exceed the capital cost of monitoring the anode currents using WIT technology.