A Hydrokinetic Turbine-Based Triboelectric-Electromagnetic Hybrid Generator for Ocean Current Energy Harvesting

Abstract

Ocean current energy, as a form of renewable energy, has immense development potential. It can significantly aid in constructing the Internet of Things (IoT) in marine environments by providing self-sustaining power to its nodes. This paper proposes a hydrokinetic turbine-based triboelectric-electromagnetic hybrid generator (HT-TEHG), composed of a hybrid generator (HG) that includes both triboelectric nanogenerator (TENG) and electromagnetic generator (EMG), and a helical vertical axis hydrokinetic turbine, designed for collecting ocean current energy. The helical hydrokinetic turbine features excellent self-starting capability and strong adaptability to flow directions. The HT-TEHG can operate stably when the ocean current velocity exceeds 0.2 m/s. Meanwhile, it can achieve an average power of 80.56 mW and an average power density of 44.52 W/m3 at least when the flow velocity is 1.0 m/s. The introduction of HT-TEHG makes it possible to harvest ocean current energy in a wider range of flow velocities. At a rotational speed of 80 rpm, the TENG component can achieve a peak power of 0.92 mW, with a peak power density of 76.56 mWm−2Hz−1. Additionally, numerical simulations on the EMG component's three-dimensional magnetic flux density spatial distribution, magnetic field line spatial distribution and voltage are conducted. The output performance of the EMG component is also tested, demonstrating a positive correlation between its output performance and rotational speed. This study presents an example of a highly reliable and adaptable device for harvesting ocean current energy, which can effectively utilize ocean current energy to power sensors at IoT nodes.

Keywords: Ocean Current Energy, Triboelectric Nanogenerator, Helical Vertical Axis Hydrokinetic Turbine