A device for generating electrical energy from mechanical motion includes a magnetostrictive generator configured to be mechanically coupled to a power conveyance path in a well bore. The power conveyance path is configured to experience an axial force change, and the magnetostrictive generator includes at least one magnetostrictive element that experiences a corresponding force change that results in a change in magnetic permeability in the at least one magnetostrictive element resulting, and is configured to experience a change in magnetic flux in a least one component that is electromagnetically coupled to at least one conductive coil, and the conductive coil is configured to generate electricity due to these magnetic flux changes.