An assessment of graphitized carbon fiber use for electrical power transmission

Significant progress has been made in the last several years toward the production of highly conductive carbon filament. Graphitized carbon fibers, made from a variety of precursor materials such as PAN, pitch and benzene, have electrical conductivity in the range 10 to the -6 power -10 to the -7 omega m, tensile strength in the range 1-3 GPa, tensile modulus in the range 100-700 GPa and density in the range 1.8 -2.2 x 10 to the 3rd power kg/m cube. These properties suggest graphitized fibers may have potential as current carrying material for electrical power transmission. This paper reviews the physical reasons for the electrical and mechanical properties and evaluate prospects for better conductivity without degradation of mechanical properties. Chemical doping (intercalation) is found capable of achieving X5-15 improvements in conductivity with some degradation in tensile strength. Various applications for electrical power transmission usage are examined, i.e., underground and overhead conduction, underground pipe, overhead towers and submarine cable. Near term usage is most probable in towers and submarine cable where high strength to weight advantages may offset the good, but not great, fiber electrical conductivity.