Alternative Energy

The ocean is one of the biggest sources of energy. Apart from the fossil fuels that dominate mainstream fuels, the ocean is also the provider of alternative energy sources like Wave energy, Tidal energy and Thermal Energy. Potentially the most powerful of these is Tidal Energy.

Tidal energy, sometimes also known as tidal power, is basically a form of hydropower that utilizes the movement of water caused by tidal currents or the rise and fall in sea levels due to the tides. Even though its utilization hasn’t reached a large scale yet, tidal power has potential for future electricity generation and is more predictable than wind energy and solar power. In Europe, tide mills have been used for over a thousand years, mainly for grinding grains.

Tidal power can be divided into two main types:

• The utilization of the kinetic energy of the water currents to power turbines. This technique is widely used because of the lower cost and lower ecological impact.

• Make use of the potential energy from the difference in height between high and low tides.

How it works

Ordinarily tidal energy requires setting up a dam across the opening to a tidal basin. The dam comprises of a sluice that is held open to allow the tide to flow into the basin, the sluice is then closed, and as the sea level drops, the normal traditionally employed hydropower technologies can be used to generate electricity from the elevated water in the basin. Research is now being done find methods to extract energy directly from tidal flow streams.

Tidal energy is currently exploited in two ways:

(1) By building semi-permeable barrages across estuaries with a high tidal range. and

(2) By harnessing offshore tidal streams. Barrages allow tidal waters to fill an estuary via sluices and to empty through turbines. Tidal streams can be harnessed using offshore underwater devices similar to wind turbines.