Towards 1-Watt Capable Rotary Triboelectric Nanogenerators for Power at Sea

Increasing at-sea power generation by Triboelectric Nanogenerator (TENG) energy harvesters in the order of 1-Watt will create significant opportunities to power ocean observation buoys and distributed sensor nodes by extending mission time and increasing sensor payload [1]. Of the many possible configurations of harvesting wave energy with TENGs, we document the rationale for choosing and developing a rotary TENG that operates by the freestanding mode. The rotary TENG prototype consists of two plates, a rotor and a stator, to take advantage of the various mechanisms of converting wave action into rotational motion. We have constructed a testing apparatus that allows us to vary several key parameters of the device: distance between rotor and stator, triboelectric material, rotational speed, number of electrodes and output load impedance. Preliminary results show that when driven at a constant 500 rpm, we can achieve a power density of 0.7 W/m3. A variable speed motor drives the rotor, which can be driven using a velocity profile informed by the equivalent to the output from a wave energy converter (WEC). This profile may be generated by the hydrodynamic simulation software WEC-Sim. The optimized rotational TENG can be stacked and driven by a single shaft, increasing the energy density of the device. The output of such a TENG could be used to power devices in the ocean at a low cost and high durability.<br/><br/>References:<br/>1. A. LiVecchi, “Powering the Blue Economy: Exploring Opportunities for Marine Renewable Energy in Maritime Markets,” (2019).