In one aspect, the present invention provides nanosized systems for generating electrical energy based on the use of a chemically reactive composition to generate a thermoelectric wave. For example, the system can include at least one nanostructure (e.g., a carbon nanotube) extending along an axial direction between a proximal end and a distal end. A chemically reactive composition is dispersed along at least a portion of the nanostructure, e.g., along its axial direction, so as to provide thermal coupling with the nanostructure. The chemical composition can undergo an exothermic chemical reaction to generate heat. The system can further include an ignition mechanism adapted to activate the chemical composition so as to generate a thermal wave that propagates along the axial direction of the nanostructure, where the thermal wave is accompanied by an electrical energy wave propagating along the axial direction.