Issue 6, 2015

Using the gravitational energy of water to generate power by separation of charge at interfaces

Abstract

When a fluid comes into contact with a solid surface, charge separates at the interface. This study describes a method that harvests the gravitational energy of water—available in abundance naturally, such as in rain and rivers—through the separation of charge at the interface. Essentially, it is found that water can be charged by flowing it across a solid surface under its own weight; thus, a continuous flow of water can produce a constant supply of power. After optimizing the system, a power of up to ∼170 μW (per Teflon tube of 2 mm in diameter) can be generated. The efficiency, defined as the energy generated by the system over the gravitational energy that the water losses, can reach up to ∼3–4%. In order to generate a continuous stream of positively-charged water, there should also be a constant production of negatively-charged species in the system. Experimental results suggest that the negative charge transfers constantly to the atmosphere due to dielectric breakdown of air. With regards to applications related to high electrical potential of water droplets, the amount of charge generated in a single water droplet is found to be equivalent to that produced by charging the water droplet with a high-voltage power supply operated at ∼5 kV. In general, the energy generated is clean, renewable, and technically simple and inexpensive to produce.

Graphical abstract: Using the gravitational energy of water to generate power by separation of charge at interfaces

Supplementary files

Article information

Article type
Edge Article
Submitted
07 feb 2015
Accepted
26 mar 2015
First published
26 mar 2015
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2015,6, 3347-3353

Author version available

Using the gravitational energy of water to generate power by separation of charge at interfaces

Y. Sun, X. Huang and S. Soh, Chem. Sci., 2015, 6, 3347 DOI: 10.1039/C5SC00473J

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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