Simulation-Based Optimization of Material Use and Personnel Safety in LPS Design

External lightning protection systems (LPS) are commonly dimensioned according to standard-based rules that ensure robust protection, but do not quantify the trade-offs between interception, personnel safety, magnetic-field penetration, grounding performance, and material demand. This paper presents a consistent 3D simulation workflow for initial evaluating these aspects. A total of 720 mesh-cage configurations are investigated for three buildings of increasing size, covering lightning protection levels (LPLs) I–IV, one to three ring earth electrodes, five specific soil resistivities, and four frequencies representing different lightning current rise times. In addition, 60 single air-termination rod configurations (hereafter denoted as single-rod configurations) at LPL II, generated using a rolling-sphere algorithm and verified by a numerical protection envelope, are analyzed for comparison. The assessed quantities include grounding impedance, prospective touch and step voltages, magnetic-field penetration, conductor length, normalized material intensity, and a first-order estimate of embodied CO2. Normalized material demand decreases with building size and from LPL I to LPL IV, while additional ring electrodes reduce grounding impedance with diminishing returns. For the same earth-termination system (ETS), the single-rod concept requires approximately 30–40% less conductor than the mesh cage while providing equivalent rolling-sphere interception and comparable grounding performance. Prospective touch and step voltages are comparable for both concepts and are governed mainly by specific soil resistivity and building size. The single-rod concept generally produces higher magnetic-field magnitudes along the investigated injection-to-center path than the mesh cage, particularly at higher frequencies. These results indicate a trade-off between material reduction and magnetic-field penetration, while the implications for the EMC of installed equipment require further investigation.