Energy: Hydro-electricity, Waves and Tides

Energy: Hydro-electricity, Waves and Tides


  • Hydro-electric power involves capturing the energy of falling or flowing water to produce electricity. This usually happens in a hydroelectric power station.

  • In a typical setup, rainwater collected in a reservoir above the power station is allowed to fall, and its gravitational potential energy is converted into kinetic energy as the water moves down.

  • This water strikes turbine blades, causing them to turn. The movement of the turbines is mechanical energy.

  • The turbines are connected to a generator, which transforms the mechanical energy into electrical energy.

  • After hitting the turbines, the water flows out into a river below.

  • Hydro-electric power is a renewable source of energy, as the water cycle replenishes the reservoir naturally.

  • However, despite not releasing greenhouse gasses during operation, hydroelectric dams can have a significant environmental impact, such as altering habitats and disrupting local ecosystems.

Wave Power

  • Wave power is another renewable source of energy that uses the movement of ocean waves to generate electricity.

  • Wave power stations use wave energy converters, devices that capture the energy of a wave.

  • As waves pass under the converter, they cause it to move. This kinetic energy is converted into electrical energy by a generator.

  • Like all renewable energy sources, wave power is potentially sustainable. However, it is currently less developed and more expensive than alternatives like wind or solar power.

  • Additionally, wave power stations can have an impact on marine life and may be vulnerable to damage from storms or rough sea conditions.

Tidal Power

  • Tidal power uses the regular movement of the tides to generate electricity, making it a highly predictable and reliable renewable energy source.

  • One common method of capturing tidal energy is by constructing a tidal barrage across a bay or estuary. As the tide comes in, it fills the barrage, and the potential energy of the water can then be captured as it falls back to sea level, similar to hydro-electric power.

  • There are also newer technologies known as tidal stream generators, which work similarly to wind turbines but are located under water.

  • Tidal power stations can have a major impact on local ecosystems, and their construction can be very expensive.

  • Even though they represent a small proportion of energy generation today, tidal power and wave power could both play a big role in our future energy mix.