a method and device for generating power using radiation pressure is described . the device comprises a turbine generator in which the turbine comprises optical resonant cavities or waveguides . the turbine rotates as a result of the force applied to the resonant cavities or waveguides by the radiation pressure of the circulating laser beam . because of the amplification of the power of the input laser beam through resonant enhancement , the photon turbine generator has the potential for overunity efficiency , lasting until the laser pumping mechanism or gain medium degrades or expires . the ptg may be built on either a macroscopic or microscopic scale . the ptg can provide clean , efficient , long - lasting power for diverse applications , while also supplying electricity to meet its own operational needs .