Energy from water or hydropower
Hydroelectricity is the energy produce from the kinetic energy of water falling from height. Approximately 25% of world electricity is produce by hydropower.
Hilly and high land areas are suitable for this purpose where there is continuous flow of water. This water is stored usually in a valley by constructing a dam. This water is then allowed to fall from high slopes which the turbines placed at the bottom of dams to generate electricity.
Advantages:
1. Once the dam is built the energy is virtually free.
2. No waste or pollution is produced.
3. It is much more reliable then wind, solar or tidal wave energy.
4. Electricity can be generated constantly.
Disadvantages:
1. It is very expensive to built dam.
2. If crack develops then stored water will flood large area causing problems for the residents of that area.
3. Constructing a dam caused adverse impact on flora and fauna.