Harnessing the power of water has been used for centuries for many useful purposes. Initially it was used for irrigation and operating various machines, such as windmills and dock cranes. But these days it has a more important use: as a renewable source of electricity.
So what is hydro power?
Well, basically it is the generation of electricity by using the natural force of water.
And how is hydro power generated ?
It is generated in 3 different ways: hydroelectric power, tidal power, and wave power.
This is the most common form of hydro-power, making up the majority of all renewable energy produced. Electricity is produced in hydroelectric dams where the force of falling water drives massive turbines.
The advantage of this type of power is that not only does it produce electricity, but the dam helps collect water for our use, so it’s a power and water source in one. Furthermore, the force of the water is so strong that megawatts of electricity can be produced to help power entire cities.
There is also a large amount of control over how fast the turbines spin. If more power is needed, the controller simply opens the wicket gates more, which allows more water through the turbines and spins them faster.
The disadvantage is the devastating effect dams can have on plants, animals and even humans. When dams are built they flood large tracts of land that were once occupied by various species and communities of people. Furthermore, the water-borne animals, such as fish can also be affected. An example would be salmon that are blocked from swimming upstream to spawn by the newly erected dam.
The second most popular type of hydro power, tidal energy is produced by currents caused from the natural ebb and flow of the tide.
This has been achieved by France and Russia since 1966 in areas with a large tidal range, such as bays and estuaries. One of the systems of tidal power works by trapping water at high tide with a tidal barrage, then releasing that water in one quick burst at low tide. This gushing water drives turbines to produce power.
Although the tides are very predictable and consistent, the problem with this system is that the turbines only operate every 6 hours (once every tide).
A second, more recent, tidal system looks very much like an underwater wind turbine. Large windmill like turbines are sunk in shallow water, where they are slowly spun by shifting tidal water.
The advantage of this system is that it is an adaptation of an already technologically advanced wind turbine – so all the refinement has been done. Furthermore, the dense water is far more efficient than wind at spinning these turbines. Thus even slow-moving water is just as effective as a strong wind.
The drawback is that the current systems can only be built in shallow water, where tidal activity is greatest. This is very limiting since many other economic activities – like oyster farming – occur in the shallows. Furthermore, these structures can damage marine life on the seafloor.
This is the youngest of the three hydropower solutions. The system harnesses the power from ocean surface wave motion, where air displaced by waves is driven through a generator than spins a turbine. The end result is electricity. These generators can either be coupled to floating devices outta sea, or fixed along the shore where seas are rough.
Although this technology is relatively new, it has been estimated that there is enough energy in ocean waves to produce up to 2000 Megawatts of power.
But, as with all hydro-power solutions, it has potential environmental issues. Conservationists are worried about the impact these structures will have on the coastline’s fauna and flora. Also, there is a possibility of water pollution if – for example – the hydraulic fluids accidentally leaked into the sea. This can be expected if the wave generators are constantly battered by rough seas.
Man has come up with ingenious ways to harness the power of nature to produce electricity, hydro power being one of them. Although it is an important renewable energy for the future, there is still much controversy over its long-term environmental impact.
Originally posted 2008-11-13 16:11:56.