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Using the water’s power is an age-old phenomenon. Over the years it has been employed for irrigation and working a variety of machines, including water-wheels. But today, it is used more importantly as a alternative energy source.

Nowadays hydro-power is generated in 3 different ways: hydroelectric power, tidal power, and wave power.

Hydroelectric dams:

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 benefit to this type of hydro-power is the dam serves two purposes - to store water and to produce power. In fact, the water has so much stored energy, that it is capable of generating thousands of megawatts of power to light up an entire city.

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.

Tidal Energy:

The second most popular type of hydro power, tidal energy is produced by currents caused from the natural ebb and flow of the tide.

It has been used in Russia and France since the 1960’s in large estuaries and bays. On method is used where water from the high tide is blocked and then channeled through turbines back into the sea as the tide goes out.

Because it works with the tides, the system is very predicable. However this is also its pitfall, since it only works every 6 hours when the tides changes.

The latest tidal power system operates where large windmill-type turbines are placed in shallow water, and spin slowly as the tide comes in and goes out.

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.

Wave Energy:

This is the latest in hydro-power technology. Here oceans surface waves displace and compress air that is then fed through turbines, that generate power. These systems are either attached on floating platforms in the open ocean, or built along the shore where waves break.

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.

However, wave power systems do have environmental concerns. Their hydraulic fluids could leak out into the ocean, causing water pollution. And the fixed structures on the coastline, can damage the natural plant and animal life on the seafloor.

Closing thought:

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.