Supercapacitors are new and powerful components for energy storage. Compared with batteries, the amount of energy they can store is low. But, as power sources they have the property to be re-loadable in a few seconds . In that case, the needed instantaneous power can reach very huge values, sometime not compatible with the power that a power network or an energy source can provide . To solve those power constraints, some solutions have been proposed which consist of using an intermediary supercapacitive tank, as exposed in  as a feeder for an electric bus with supercapacitors. Experimental results are presented, defining the profile of the instantaneous power-level, which is controlled in order to achieve a fast energy transfer.