Optimal Design and Simulation of Solar Photovoltaic Powered Cathodic Protection for Underground Pipelines in Libya

In Libya, pipelines are being used as means of transferring hydrocarbon from wellheads to export sea ports, refineries, storage tanks, steel factory and power plants. Steel pipeline is widely used because it is the safest means of transporting hydrocarbon and other oil products as well as its cost effective. However, one of the challenges facing oil and gas sector is corrosion on infrastructure facilities and processing units. Cathodic-protection (CP) is an electrical method used to protect metallic body in contact with the earth from corrosion. A photovoltaic (PV) provides a reliable solution for powering remote CP stations, enabling the placing of CP units in any location along the underground pipeline, thus ensuring optimal current distribution for the exact protection requirements. In this paper the sizing of the system is determined based on the electrical power needed for the catholic protection, characteristics of the used PV module and the meteorological data of the installation site. Matlab/Simulink and PVsyst V6.43 software are used as tools for optimal design, sizing and simulation of the PV powered cathodic protection system components. In addition to that estimation of system cost was investigated and compared with the conventional system. The results show that using solar energy powered cathodic protection system for underground pipelines is practical and very beneficial besides being economical, especially considering the rapid decreasing in the prices of PV systems components and the increasing of its efficiencies and reliability.