The paper deals with the calculation of transient currents and voltages along curved wire structures buried in a lossy ground using the generalized Telegrapher's equations. The influence of a lossy half space is taken into account by the simplified reflection coefficient arising from the modified image theory (MIT). The concept of the scattered voltage is computed via boundary element formalism provided the current distribution is already known. Computational examples are given for the transient voltage induced along the grounding grid and grounding system for wind turbines (WTs).