The strong-minded will not faint, even when all is lost; the elephant stand firm even when surrounded by a shower of arrows.[Thirukkural 597].
70% of water on earth's surface and that too in liquid form ... think about the possibilities ... its available on earth in vapor form, water as liquid and ice or snow as solid. Water is the first molecule scientists look for today to assess a planet from the perspective of sustenance of life.
Isn't it a wonder that of all planets across the known universe so far only earth was chosen to have water in all three known forms and then life as well ? The importance of water cannot be understated in any context which is as important as sun to sustain life on our planet.
From Energy perspective, the equilibrium for water persists in different formats i.e. water can be found at a height which can be converted to power, the chemical composition of water with mixed salts may differ at different levels in ocean that also carries potential and if that wasn't enough, water streams and tides are also are being utilized as energy source along with difference in temperature of ocean water between surface and lower or deeper areas.
Energy from water can be derived in so many ways today and it is still being explored today to extract energy from the mentioned opportunities above in the most efficient manner. When energy is consumed from water having a head or height its usually used in Hydro projects to channel and convert the water energy into electricity.
In India the taxonomy of these hydro projects works on this principle:
Micro: upto 100 KW
Mini: 101KW to 2 MW
Small: 2 MW to 25 MW
Mega: Hydro projects with installed capacity >= 500 MW
Thermal Projects with installed capacity >=1500 MW
Though there are various aspects of extracting this energy by use of dam, it is possible to extract water from a flowing river while working on its kinetic energy directly this sort of technology does exist but is not relevant today to provide a substitute for base load which dam based technology provides. But the problems with Dams are not less, from socio-economic front to technical perspective the advancement of technology can't give a solution to all issues raised by construction of dams.
Like for example, creating a dam would directly imply displacing people from their lands who have been living near the river embankments, not only this a huge area of cultivable land and forest is also lost in this process. The people can only resort to re-start their settlement on higher grounds. The lands and forests are also lost for good once the water submerges them.
That's not the only problem, when it rains heavily the sluice gates have to be opened to compensate for increased level of dam water ... this has direct implication on the population and lands using the dam outlet for irrigation and they have to face the brunt perhaps every rainy seasons which has become quiet erratic with climate change.
Dams have a very annoying issue of silt which keeps depositing on its base on the river side and quiet often the dam maintenance has to take care of the de-silting aspect of the dam which reduces the overall efficacy of electricity generation there and also makes the land where this water flows devoid of rich nutrients that the soil needs which is contained in the silt.
Having said that within India Hydro Power is next to Thermal Power generation in providing a base load even with so many ecological, socio-economical impacts in addition to it being a renewable source of energy. Is there an alternative to dam solution, is it possible to not create such huge water masses and get the energy out of it ... the answer is tricky and solution formulation for the same is work in progress and it will take sometime to reduce the impacts of dam for hydro-power so that one day they could be taken down against the alternative implemented and rivers can flow freely again.
