How Controlled Potential CP Systems For Subsea Can Reduce Cost And Improve Safety (C2026-00444)

Joshua Jackson, Alexandra Carreno, Ali Koochekzadeh, Bryan Fahimi

Traditional subsea cathodic protection (CP) routinely pushes steel potentials far past minimum protection criteria. This chronic overprotection raises total current demand, accelerates anode consumption, inflates installation weight, and—critically—drives the hydrogen evolution reaction through a higher cathodic overpotential. The greater the potential difference, the higher the hydrogen flux into high‑strength steels and other alloys, amplifying hydrogen embrittlement risk. 
We propose an alternative architecture using controlled‑potential anodes (CPAs): compact, spatially distributed anodes designed for narrow ranges (e.g., −0.80 to −0.90 V vs. Ag/AgCl/seawater). These CPAs minimize the driving force for hydrogen generation while still satisfying protection criteria. In contrast, other "low‑voltage” galvanic anodes derive their performance from alloy activation kinetics. Their efficiency can drift with temperature, biofouling, or film formation, and they progressively form aluminum hydroxide sludges that foul surfaces and erode current output over time. CPAs avoid this decay; very little alloy is consumed and no phase changes occur over time. We review the model, expected reductions in current and mass, and the corresponding improvements in safety (lower hydrogen charging), logistics, and lifecycle economics. Guidance will be offered for integrating CPAs into new designs and retrofits, and for aligning with existing design frameworks without requiring wholesale rewrites of current CP specifications.