Water at the surface of the sea is hot 

whereas water in the deeper sections is cold.


This difference in temperature is used to transform energy in Ocean Thermal Energy Plants.


Ocean Thermal Energy is also called OTEC - Ocean Thermal Energy Conversion

Ocean Thermal Energy Plants

In an Ocean Thermal Energy plant, 

  • We use Water at the surface, and water at a depth of 2 kms (so that temperature difference is atleast 20°C)
  • The warm surface water is used to boil a volatile liquid like ammonia
  • The vapours of ammonia are used to turn the turbines of the generator
  • The cold water at the bottom is used pumped up to condense the vapour into liquid


Advantages of using Ocean Thermal Energy

  • Power generated from OTEC is renewable and pollution free
  • The output generated from Ocean Thermal Energy shows very little seasonal or daily variation
  • Electric power generated can also be used to produce hydrogen.
  • The cold water pumped in the OTEC plant can be used for other things such as air conditioning and refrigeration


Disadvantages of using Ocean Thermal Energy

  • It is only suitable in tropical regions since water at the surface can only be heated there
  • The initial set-up costs are high


  1. Class 10
  2. Chapter 14 Class 10 - Sources of Energy (Deleted)

About the Author

CA Maninder Singh's photo - Founder at Teachoo
CA Maninder Singh
CA Maninder Singh is a Chartered Accountant for the past 11 years and a teacher from the past 11 years. He teaches Science, Accounts and English at Teachoo