This paper presents an approach towards realising novel multifunctional polymer composites with combined structural and electric energy storing ability. A series of structural capacitors were made using three thicknesses of DuPont Mylar A thermoplastic PET as a dielectric separator employing carbon fibre/epoxy pre-pregs as structural electrodes. Plasma treatment was used as a route for improved epoxy/PET adhesion. The manufactured materials were mechanically and electrically tested to evaluate their multifunctional efficiency. The multifunctional materials developed show good potential for replacing steel, aluminium and other materials with lower specific mechanical properties but do not match the high specific mechanical and electrical performance of monofunctional composites and capacitors.