A device for harvesting and storing triboelectric charge generated on an exterior surface of a moving vehicle is provided. It is characterised by comprising; a supercapacitor comprised of nano-carbon-containing electrodes; an ionic liquid electrolyte and at least one ion-permeable porous membrane; at least one first element exposed to aerodynamically-induced frictional forces acting thereon and on which the charge is caused to build up and connected to at least one of the electrodes of one polarity; at least one second element having a lower electrostatic potential than the charge-collecting element and connected to at least one of the electrodes of the other polarity; a voltage modification or impedance conversion circuit arranged between the first and/or second elements and the supercapacitor; means to connect the device to an operative component requiring electrical power and a controller for managing the performance of the device and switching between energy-harvesting and energy-utilisation modes. The device is especially use for deployment in the wing of an aircraft to utilised triboelectric charge generated thereon.