1.9.5 Hydro Energy
Water flowing from higher level to lower level can drive turbine rotor and give mechanical energy. Hydroturbine drives generator rotor and the generator delivers electrical energy. Hydro-electric energy contributes 20% of India's electrical energy About 8% world's electrical energy needs are from hydro-electric power plants.
1.9.6. Renewables and Non-conventionals
Recently considered energy resources are solar, wind, geothermal, ocean thermal, ocean wave, ocean tide, mini-hydro, bio mass, chemicals, waste fuels etc. These are available from nature in renew. able but periodic/intermittent form. Energy technologies for use of renewables are being rapidly developed. Present contribution of renewables in the world is less than 2% (excluding hydro). This is likely to increase to about 10% by 2000 AD and to about 15% by 2016 AD. Renewables are cheap, clean energy resources. However, solar and wind sources are intermittent, diffused and their conversion technologies are presently costly and suitable only of smaller plant capacities