Talking About Green

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.

Electricity from hydro-power can be generated in three different ways: in hydroelectric dams, using the tides, and through the ocean’s waves and currents.

Hydroelectric dams:

Hydro-electric dams produced up to 90% of the world’s alternative energy, so it plays a vital role. Here, dams release water through huge turbines, which are spun by the force of the water.

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:

Using the tides is the second most common form of hydro-power. Here, electricity is generated by using the low and high tides.

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.

The only drawback with using such a system is that it only operates as the tide turns, which is every 6 hours.

Another, more modern tidal energy system works where large turbines (that look like wind turbine) are sunk in the shallows, and are spun by the shifting tidal currents.

The nice thing about this tidal system is that the technology is advanced and derived from our land-based wind turbines. And water is much denser than air, meaning it takes only a small current to get the turbine spinning.

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 Power:

This is the youngest of the three hydro-power 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.

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:

Over the years we have come up with advanced methods of using water to produce power. Though there are a variety of benefits to using this kind of renewable energy, there are still a number of social and environmental concerns.