Researchers at Indian Institute of Technology (IIT), Guwahati developed materials that can produce energy from water, on a small scale. The new way of producing energy can be employed in household environments – like tap water – to support the concept of decentralization of energy sources.
“In the centralized energy generation model, one large plant produces energy for an entire region, in contrast, the decentralized energy model introduces a large number of small generation devices that can be employed to generate in every household. The excess energy produced in households can be transported nearby areas where there is an excessive need for energy,” an official release stated. The researchers of IIT Guwahati employed the nanoscale phenomenon called ‘Electrokinetic streaming potential’ to harvest energy from flowing water on the small length scale like water flowing through household water taps.
Similarly, the “Contrasting Interfacial Activities” different types of semiconducting materials were employed to generate power from stagnant water.
The research team, led by Kalyan Raidongia from Department of Chemistry, IIT Guwahati, along with his research team Jumi Deka, Kundan Saha, Suresh Kumar and Hemant Kumar Srivastava, worked on the possibilities. Their findings were recently published in ACS Applied Nanomaterials.
The generation of energy from water in various forms – river flow, ocean tides, stagnant water, and even raindrops, is now known as “blue energy”. While hydroelectric power from rivers is the traditional form of blue energy, there have been efforts to harness the power of water in other ways in recent years.
One out-of-the-box blue source is electrokinetic energy. “When fluids stream through tiny channels that are charged, they can generate an electrical voltage, which may be harnessed through miniaturized generators”, explains Raidongia.
Although the exploration of such electrokinetic phenomena and their possible use for energy conversion have been known for more than half a century, they have not been harnessed because of low efficiency arising from the unsuitability of channels for the fluid stream. The humble efficiency of electrokinetic streaming potential based energy generating devices is attributed to the trade-off between high flow-rate and nanofluidic confinement.
The researchers of IIT Guwahati demonstrated that power output can be improved by thousand times by attaining the best out of these parameters through biconical nanofluidic channels that interconnect tetrahedral and octahedral voids in the close-packed silica spheres. Enhancement in the power density can be brought about through control of multiple parameters such as the diameter of the close-packed spheres, number of the spheres, the contact area of the electrodes, and pH of the streaming water, and the team is currently involved in such optimization efforts.