Ocean Thermal ENERGY

• The surface of the ocean is at a higher temperature than the layers below.
• This is because of the sun's heat warms up the upper layers of the sea.

• This temperature difference is exploited to generate energy

• A minimum temperature difference of 20 degrees C is needed between water at the surface and at a depth of about 2 km.

• This requires Ocean Thermal Energy Conversion plants which converts ocean thermal energy to electricity.  

Ocean Thermal Energy Conversion plants

• The water at surface of the ocean which is at higher temperature vaporizes liquid ammonia.

• The vapour ammonia now moves the turbine which generates electricity.

• The vapour ammonia then, is condensed using the water at the bottom layers of the ocean. It now again becomes liquid ammonia.

• This is again heated by the heat from the top layers and the process continues

aDVANTAGES

·         More reliable (more than solar/wind)

·         Renewable

·         Low maintenance cost

DISADVANTAGES

• Initial cost is very high

• Not environment FRIENDLY because construction of such plants COULD harm AQUATIC plants and animals.