Loss of equipotential during lightning ground potential rise on large earthing systems

The implications of lightning ground potential rise in the context of large earth electrodes, such as those associated with free field photovoltaic plants, are highlighted in this paper. With limited application of IEC 62305-2, the well-known international lightning standard, when it comes to large electrodes, wire-line technology and high soil resistivity, the effect of lightning GPR raises in importance and is addressed in this paper. Aspects, such as, equipotential, ground potential difference, effective area and cost, important to the plant design engineer, are revisited and discussed against the backdrop of electrode performance under lightning GPR.