NOVELTY - Piezoelectric-photovoltaic structure for converting solar and mechanical energy into electrical energy, comprises superposed layers including a photovoltaic layer and a piezoelectric substrate.    USE - The piezoelectric-photovoltaic structure and power conversion system are useful for converting solar and mechanical energy into electrical energy; and for generating, storing, distributing, or consuming electrical energy (all claimed).    ADVANTAGE - The invention provides improved method of storing, consuming, and/or generating electrical energy scavenged from both solar and mechanical sources; and improved power generation system for harvesting both solar and mechanical energy.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are:    (1) a method of forming piezoelectric-photovoltaic structure comprising providing a piezoelectric substrate and superposing a photovoltaic layer over the substrate;    (2) a power conversion system for converting solar and mechanical energy into electrical energy comprising a piezoelectric-photovoltaic structure having superposed layers including a photovoltaic layer and a piezoelectric substrate; a first circuit connected to a top electrode and a bottom electrode of the piezoelectric substrate; and a second circuit connected to an anode and a cathode of the photovoltaic layer; or a power conversion system for converting solar and mechanical energy into electrical energy comprising a piezoelectric-photovoltaic structure having a photovoltaic element and a piezoelectric element; a first circuit connected to the piezoelectric element; and a second circuit connected to the photovoltaic element, where at least one of the first and second circuits is connected to a direct current (DC)-DC converter;    (3) a method of generating, storing, distributing, or consuming electrical energy, comprising using a power conversion system to convert mechanical or solar energy into electrical energy; and connecting one or both of the first circuit and the second circuit to an electricity distribution circuit or to an electricity distribution network or to an electrical load or to an energy storage device;    (4) a method of generating and distributing electrical energy comprising using the power conversion system to convert mechanical or solar energy into electrical energy; and connecting the energy storage device to an electricity distribution circuit or to an electricity distribution network or to an electrical load; and    (5) a power conversion array comprising a set of power conversion systems connected in series at their output terminals.