Electro-Kinetic Streaming to Tap Energy from Water | 31 Dec 2019

Why in News

The Indian Institute of Technology-Guwahati (IIT-G) researchers have developed materials that can produce energy from flowing or stagnant water in households.

• The decentralised energy model involves a large number of small generation devices which can generate energy in every household and the excess energy can be transferred to energy-deficient areas nearby.

Key Points

• The generation of energy from water in various forms like river flow, ocean tides, stagnant water and even raindrops is now known as "Blue Energy”.
  
  • These are the traditional form of blue energy and there have been efforts to harness the power of water in other ways. One such out-of-the-box blue source is electrokinetic energy.
• Two different methods have been employed to harvest energy from the flowing water and the stagnant waters.
• Electro-Kinetic Streaming Potential:
  
  • By this method, energy can be harvested from flowing tap water.
  • When fluids stream through tiny channels that are charged, they can generate an electrical voltage, which may be harnessed through miniaturised generators.
  • Although the exploration of such electrokinetic phenomena and their possible use for energy conversion have been known for over half a century, they have not been harnessed because of low efficiency arising from the unsuitability of channels for the fluid stream.
• Contrasting Inter-Facial Activities:
  
  • These entail different types of semiconducting materials to generate power from stagnant water.
  • Devices were fabricated with doped graphene flakes for generating power by dipping in a bucket of water in the stagnant water source to “complementary charge transfer activities”.
    
    • Graphene is the sheet produced by oxidation followed by reduction of natural graphite flakes.
    • Graphene was modified to manipulate its electron density so that even stagnant water in contact with this form of graphene can produce energy.

Source: TH