Sustainable energy refers to the sources of energy that can meet the demands of the present population without compromising on the needs of the future generation. With the increase in the planet’s green house stress and ever decreasing fossil fuel reserves, there is an indispensible need for sustainable energy forms. Wind, water, and solar energies have long been identified as renewable resources with high sustainability quotient.
Water covers two third of earth’s surface and abundantly found in major parts of the civilized world. In its basic form hydropower can provide high to moderate efficiency energy. The energy is tapped through the kinetic energy of flowing water, found in water bodies such as rivers, seas, and oceans.
Damming major rivers for water conservation and energy generation has been an age-old practice. However, the other major resource – tidal energy is yet to catch on. Limited sites for tapping tidal power and lack of equipment that can withstand the salt erosion seem to be the major hurdles in tapping tidal.
A more recent form of tapping energy from water refers to utilizing the heat energy from the thermal gradients of the oceanic water. The difference in the water temperatures of oceanic waters in various regions and pressures is high enough to create steam strong enough to run the electricity storing turbines. Work on oceanic thermal energy is promising but in its nascent stage.
Today approximately 20% of the world’s energy is supplied through hydropower, suggesting a huge untapped resource and market. Improvising on efficiency and availability of water energy is the need of the hour.