Ocean

Waves, Tides, and Currents are all potential energy sources. Although these are all vast and uncontrollable sources, the amount of potential energy throughout the ocean is immense. Thus far, there are two ways of extracting energy from the ocean.

Tidal Power Station:

How does it work?

At high tide, water is let into a reservoir through “sluice gates”. The gates then shut, forming a dam. At low tide, the water is released through a turbine and used to generate electricity.

(Picture pp. 243)

Disadvantages:

In most areas of the world, the difference in height between high and low tide is not enough to work the turbine. Only in very few specific places can this source of energy work.

Ocean Thermal Energy Conversion (OTEC):

How does it work?

Solar heating has resulted in warmer surface waters of the oceans in tropical latitudes, than the deeper waters in the same areas. An OTEC plant is a large heat engine that uses the temperature difference to run a turbine and create electricity.

(Picture???)

Advantages:

The amount of energy stored in the thermal layers of the ocean is immense.

Disadvantages:

	Very expensive to produce the necessary tools-results in only a small amount of energy extracted.
	Inefficient due to small temperature differentials, and only in certain parts of the world.