Comparison between pipe-type grounding electrode systems installed vertically versus horizontally

The application of optimality criteria to the sizing of earth grounding systems (EGR) employing pipe-type electrodes has led to the accumulation of a substantial body of significant data 1,2, enabling a comparison between two design alternatives determined by the vertical versus horizontal placement of the electrodes. The first premise motivating this approach is the fact that near-surface soil may be modeled as an “infinite conducting half-space,” in which the flow of conduction current from the EGR is also influenced by the skin effect. Consequently, the tendency to use relatively long tubular electrodes installed vertically 3 may reduce the economic efficiency of the EGR. Without seeking to justify a preference for either of the above constructive alternatives, the present research aims to identify the domains of applicability in which each variant proves more advantageous. In this context, it is reiterated that the physical models of both EGR types considered herein are those specified in standards and regulations 3–5. Moreover, the following four principal optimality (minimization) criteria were proposed and applied: ground footprint area (denoted AP), total volume occupied by the EGR ( VP), metallic mass of the electrodes and interconnecting conductors ( MP), and the total investment cost of the EGR ( IP).