I. Introduction
The design and modeling of an adequate grounding and lightning protection systems (LPS) for tall structures extremely susceptible to lightning strikes (e.g., power line towers and telecommunication towers) has been an important area of research in last few decades [1]–[4]. Recent contribution to such a research area is related to LPS for wind turbines, used in the process of renewable power generation [5]–[7]. Due to transient nature of a lightning strike, a direct time domain modeling of grounding and LP systems is a convenient tool. One of the basic elements of every complex grounding system is a horizontal grounding electrode. Transient current distribution, i.e., current flowing along the grounding electrode, due to a lightning strike, represents a fundamental quantity that can be used for determining other parameters of interest (i.e., scattered voltage, transient impedance, etc.).