An earthing system is a critical requirement in order to safely protect and ground lightning currents. Earthing is used to conduct lightning strikes minimally to the earth instead of causing fies and damaging equipment. It is also used to control noise in audio, video and computers.
This has implications for the safety and electromagnetic compatibility of the power supply. The purpose is to maximise the surface area contact with the surrounding soil. Increasing the surface area, the contact resistance of the earthing system is lowered and surge impedance of the earthing system is improved