Hydro One, the power company in Ontario, wants galvanized ground rods. mostly elsewhere, the copper clad are the norm. Different soils must have different grounding problems?
Soil moisture seems to be the real issue. Soil acidity could cause more corrosion, affecting the current flow, but copper is still a better conductor.
The only reason I can think of them requiring galvanized ground rod is that they are steel and more likely to be able to be driven into badly compacted soil to the depth they need, rather than the copper rods, which are softer. That way, regardless of the soil density, they can be assured of the best ground possible.
Ed
