OCEAN THERMAL ENERGY CONVERSION

Ocean Thermal Energy Conversion (OTEC) is a marine renewable energy technology that converts solar radiation to electrical power by the temperature difference between the deep cold ocean water and warm tropical surface water.

1. OCEAN THERMAL ENERGY CONVERSION By- SNEHANSHU DAS 7 th SEM, B.TECH

2. CONTENTS INTRODUCTION HISTORY OCEAN THERMAL ENERGY CONVERSION TYPES OF OTEC SYSTEM APPLICATIONS BENEFITS & DRAWBACKS OF OTEC FUTURE PROSPECTS CONCLUSION REFERENCES

3. INTRODUCTION Ocean Thermal Energy Conversion (OTEC) is a marine renewable energy technology that converts solar radiation to electrical power by using the temperature difference between deep cold ocean water and warm tropical surface water. Oceans cover more than 70% of Earth’s surface and captures a large part of the sun’s heat, making them the world’s largest solar energy collector .

4. HISTORY In 1881, Jacques Arsene d'Arsonval, a French physicist discovered tapping thermal energy of the ocean. Georges Claude, built the first OTEC plant in Cuba in 1930 . Tokyo Electric Power Company built & deployed a 120 kW closed-cycle OTEC plant in 1981 on the Nauru island near south pacific ocean. In 2002 , India successfully tested a 1MW OTEC plant near Tuticorin, Tamil Nadu.

5. OCEAN THERMAL ENERGY CONVERSION Ocean Thermal Energy Conversion (OTEC) is an electricity generation system .. In equatorial areas the temperature between the warm surface water and the deep cold ocean water differs by about 20°C . Bigger the temperature difference, the higher will be the efficiency . Power is converted to high voltage DC , and is cabled to shore for conversion to AC and integration into the local power distribution network .

6. MAIN COMPONENTS OF OTEC SYSTEM Water pipes (20inch radius) Heat exchanger ( Evaporator & Condenser) Turbine G enerator

7. TYPES OF OTEC SYSTEM There are three types OTEC system: Closed or Anderson Cycle OTEC System Open or Claude Cycle OTEC System Hybrid Cycle OTEC System

8. In the closed cycle, a working fluid, such as ammonia, is pumped through a heat exchanger (evaporator) and vaporized . This vaporized steam spins a turbine . The cold water found at the depths of the ocean condenses the vapor back to a fluid where it returns to the heat exchanger (condenser). Evaporated fluids expands in turbine , which runs a generator to produce power. B oiling point of ammonia is (-33°C). CLOSED CYCLE OTEC SYSTEM

9. CLOSED CYCLE OTEC SYSTEM

10. OPEN CYCLE OTEC SYSTEM In open-cycle, the sea water is itself used to generate heat without any kind of intermediate fluid. Warm seawater is expanded rapidly in a vacuum chamber where some of it 'flashes' to steam. This steam is used to drive a steam turbine. From the exhaust of the turbine, the vapor is condensed using cold seawater. V apor expands and spins a turbine coupled to a turbo-generator to produce current.

11. SCHEMATIC OF OPEN CYCLE

12. HYBRID CYCLE OTEC SYSTEM A hybrid cycle combines the features of the closed- and open-cycle systems. W arm seawater enters a vacuum chamber and is flash-evaporated, similar to the open-cycle evaporation process. The steam vaporizes ammonia, working fluid of a closed-cycle on the other side of an ammonia vaporizer. V aporized fluid drives a turbine to produce electrical power. This fluid leaves the condenser and is pumped to the evaporator to repeat the cycle.

13. HYBRID CYCLE OTEC SYSTEM

14. APPLICATIONS OF OTEC Air-conditioning Aquaculture Desalinating Water Mineral Extraction Power Generation Refrigeration

15. BENEFITS Economic Benefits: Continuous supply of electricity throughout the year Reduced capital expense to power c ompanies Life cycle cost savings Environmental Benefits: Reduces dependence on fossil f uels Zero emissions and it saves nearly 7000 tons CO 2 a year per MW.

16. DRAWBACKS The initial cost of setting up an OTEC project is quite high. The maintenance cost is more since the components are subjected to a large amount to destructive forces of nature. Construction of OTEC plants and lying of pipes may effect marine ecosystem .

17. FUTURE PROSPECTS OTEC Technology has the potential to be integrated with other commercial systems and products (e.g.- potable water and hydrogen). Energy and Economics can be enhanced by employing super efficient Hybrid Cycle OTEC system.

18. CONCLUSION Ocean Thermal Energy Conversion is a potential source of renewable energy that creates no emissions. It is fuel free. If proper research and development is carried on in this field we can satisfactorily fulfil the needs of the people and reduce our dependence on fossil fuels which contributes to large part of our energy requirement but is bound to be exhausted in a few years .

19. REFERENCES https :// en.wikipedia.org/wiki/Ocean_thermal_energy_conversion https ://www.makai.com/ocean-thermal-energy-conversion / http :// www.livescience.com/3155-energy-debates-ocean-thermal-energy-conversion.html http://coolmyplanet.org/otec / http://www.otecnews.org/what-is-otec /

20. Thank You!