A systematic study by complementary techniques shows that PET-waste from plastic vessels is a competitive precursor of carbon electrodes for supercapacitors. PET derived-activated carbons follow the general trends observed for highly porous carbons and display specific capacitances at low current density as high as 197 F g(-1) in 2 M H2SO4 aqueous electrolyte and 98 F g(-1) in the aprotic medium 1 M (C2H5)(4)NBF4/acetonitrile. Additionally, high performance has also been achieved at high current densities, which confirms the potential of this type of materials for electrical energy storage. A new method based on the basic solvolysis of PET-waste and the subsequent carbonization seems to be an interesting alternative to obtain porous carbons with enhanced properties for supercapacitors. (C) 2010 Elsevier B.V. All rights reserved.