As cathodic protection systems are fed from 0.C. sources, a difficulty will be faced to find a suitable 0.c, source if such systems are used to protect petroleum tanks or pipe lines which lie in isolated areas far away from the existing transmission lines, Usually 3 methods could be adopted here:
i) Installing a transmission link with a rectifier substation between the nearest convenient existing transmission line and the D.C. cathodic protection source.
ii) Using private motor-generator sets; where the motor as a prime mover works by convenient fossil fuel.
iii) Using storage battery systems, the capacity of which must be large enough to supply the required protective current during a period necessary for charging a second battery at the nearest charging station and replacing the one in use. In this case the charging battery system may he fed from rectifier substations, or private D.C. generating sots whose prime movers operate with conventional or non-conventional
energy sources.
This paper presents the limitations and conditions required for the conveniency of applying the non-conventional energy sources (photovoltaic) and their economical aspects in charging such batteries; together with examples of calculations clarifying the analytical steps and assumptions adopted in this study by means of which the final conclusions and results presented here were deduced. A simplified approach for the solar specific annual energy cost calculations using nomogram analysis and performance charts applied to local conditions in this respect is present od also in this paper.