There are a number of applications which require an energy storage device capable of high power output combined with acceptable energy density. Double layer capacitors based on carbon technology can fulfil these requirements. But the present state of the art and the properties available are still not adequate for its realization due to its relatively high internal resistance and capacitance-dependence on the frequency. A more promising approach is to use glassy carbon (GC) as an electrode material because it displays the required properties. Early experiments based on this concept yielded specific capacitances up to 10 F/cm(2). A 3-celled unit using H2SO4 as electrolyte measured 3.7F at 2.7V. In this contribution, the GO-concept will be described and compared with other Supercap-technologies that are available.