Anodes need to be in soils or electrolytes in order to deliver cathodic protection current in buried structures. HSCI anodes work well in natural waters, but they are seldom buried in the ground without being bedded in high quality carbon, fines (coke). Coke increases the area of anodic surface in contact with the earth to minimize resistance, and most importantly, mitigate groundbed drying. Calcined petroleum coke breeze also serves to prevent drilled deep-wells from collapsing inwards.

Currently Density Limitations: In operating systems, high silicon cast iron anodes are invariably called upon to discharge current well below the limit that HSCI is able to handle without failing catastrophically. Most frequently, for earth or mud groundbeds, current density must be limited to prevent either groundbed dying by electro-osmosis, or gas blockage from electro-chemical processes around the anodes.

How Current Density affects CP groundbed design is explored in: Groundbed Design with HSCI Anodes.

Anode Life depends on the consumption rate of high silicon iron in the environment involved. As rule, HSCI groundbed designs assume that the consumption rate will be about 0.31 kg/amp-year(0.75lb/amp-year) at current discharge density ranging from 5 to 10A/SqM (2.5A/Sqft) indicates that a sulphate environment will increase consumption relative to chloride by roughly 15% to 30%. From the same tests, consumption was nearly 20% higher for conventional sand cast silicon iron, than for Anotec Chill Cast Silicon Iron. In a different test, a 50% increase in the consumption rate of sand cast silicon iron corresponded to a 50% increase in current density. In contrast, a 50% increase in consumption rate of Anotec Chill Cast material required a 500% increase in current density.

Anotec attributes the significantly better performance of Chill Cast anodes, compared to Sand Cast and Centrifugal Cast, to the superior Metallic Structure achieved by Anotec's Chill Casting process. In salt water test for HVDC groundings, Chill Cast HSCI electrodes gave 16% longer life than sand castings. It is interesting that current reversal did not appear to increase consumption for these grounding electrodes.