Eco-generation of electrical energy harvested from the flutter phenomenon of a plate wing is studied using the quasi-steady aerodynamic theory and the finite element method. The wing is modeled as sounding rockets’ wings. We harvest electrical energy from supersonic flutter by using piezoelectric patches and electric devices. To assess their harvesting performances, we simulate flutter dynamics of the plate wing to which piezoelectric patches are attached. We demonstrate that our harvesting system can generate 10 times more electrical energy from wing flutter than conventional harvesting systems can.