Harvesting Blue Energy: Triboelectric Nanogenerators
Covering 70% of the earth’s surface the ocean is the largest reservoir of energy on earth and researchers have been exploring how to harness that ocean energy to address the world energy crisis and the pollution problems caused by thermal power generation.
A research team from the Faculty of Engineering of The Chinese University of Hong Kong (CUHK) has designed new modular nanogenerator that can harvest energy from various different types of motion, from ocean waves to a person’s body movements.
The new devices are a type of triboelectric nanogenerator (TENG), which generate electricity through friction and have demonstrated they’re able to harvest energy from footsteps, tapping on a touchscreen and even raindrops hitting solar cells. However, they have limitations. TENGs require solid surfaces to remain in contact for sustained periods which can be tricky to maintain, and over time can damage each other.
The new devices are a type of triboelectric nanogenerator (TENG), which generate electricity through friction and have demonstrated they’re able to harvest energy from footsteps, tapping on a touchscreen and even raindrops hitting solar cells.
The CUHK team has developed a water-tube-based triboelectric nanogenerator (WT-TENG) that can efficiently convert various irregular and low-frequency mechanical energies, including ocean wave energy, into electricity, providing a new avenue for the development of “blue energy”.
Taking advantage of the flexibility of water, the WT-TENG can be operated in various modes, including rotation, swing, seesaw, and horizontal linear modes, to harvest energy from diverse mechanical movements in the environment, such as ocean waves, wind, body and vehicle movements. Multiple small WT-TENG units can easily be combined into a larger integrated unit delivering electric outputs.
“Previous designs of ocean energy harvesters have been equipped with electromagnetic-based generators which are large in size and heavy, and will only generate power if the frequency of ocean waves reaches a certain high level,” said Prof. Zi Yunlong, part of the CUHK team. “Our latest research has overcome the technical hurdles and will promote the use of nanogenerators, especially in blue energy harvesting, offering a new direction for the development of renewable energy to achieve carbon neutrality.”