• Perennial Streams in the hilly regions
  • Canal drops
  • Dam/Check dam over flows
  • Waste water

How does it work?

  • Potential energy is converted into kinetic energy.
  • This energy is transmitted to a turbine runner which changes it to a mechanical energy ( shaft power).

P = 6 X Q X H Watts.

Q – flow rate in lps
H – Head in meter
Overall efficiency assumed – 60%
  • Civil and hydraulics
    • A diversion weir
    • Intake works
    • A water channel
      • Earthen
      • Masonry lining or Concrete
      • Flumes or aqueducts made from sheet metal, wood, pipes,etc
    • A forebay tank
    • Penstock
      • PVC
      • HDPE
      • Mild steel
      • Concrete
    • The Powerhouse
    • A Tailrace
  • Mechanical
    • Turbine
      • Pelton
      • Crossflow
      • PAT
    • Manifolds
  • Electrical
  • Social


  • Cheapest of all renewable energy options.
  • It does not consume the water, after use it is available for other purposes.
  • Power is usually continuously available on demand.
  • Given a reasonable head, it is a concentrated energy source.
  • The energy available is predictable.
  • No fuel and limited maintenance are required, so running costs are low (compared with diesel power).
  • It is a long-lasting and robust technology; systems can last for 50 years or more without major new investments.
  • Technology is simple enough to be transferred and accessed in the remote rural areas.

Social Aspects

  • Allows direct access of water resources by the community and could meet its energy requirements.
  • Is small enough to avoid over exploitation of natural resources.
  • Is a decentralised unit and could provide wider access to the decision making process of the community.


  • Mostly site specific.
  • Reliable site data has to be collected for guaranteeing output.
  • Maximum useful power output is limited for a site, making capacity expansion difficult.
  • Seasonal variations affect the performance

Uses of Power

  • Off grid home lighting
  • Home power for lighting
  • TV, fridge, etc
  • Off grid resort /hotel power
  • Mechanical power for generator
  • Small industries electrical requirement
  • Street lighting
  • Grid connected hydro for 24/7

Measure the Flow rate and Height difference.

Flow Rate:
  • Bucket method
  • Float method
  • Salt dilution
  • Water tube
  • Altimeter
  • Civil survey