An energy harvester for use to provide power to metrology hardware like gas meters and flow measuring devices. The energy harvester may include an actuator that mounts to a substrate found in the gas meter or in an adjacent, collateral device like a pressure regulator. The substrate may embody a diaphragm or membrane, possibly a thin, flexible or semi-rigid member. The actuator may include piezoelectric transducers that mount to this member. In operation, the piezoelectric transducers can generate an electrical signal in response to mechanical activity (or energy) from the thin member. The electrical signal can be directed to the flow device to replace, supplement, or recharge a power source that powers electronics necessary to expand functions on the flow meter.