OTEC harnesses the temperature difference between shallow and deep ocean waters to generate electricity. There are two types of OTEC plants - closed-cycle plants that use ammonia as a working fluid and open-cycle plants that use seawater. OTEC is a promising renewable energy source as the oceans hold vast thermal reserves and can generate power continuously. While OTEC development faces challenges related to costs and environmental impacts, many countries are exploring OTEC to reduce dependence on fossil fuels.

1. OTEC
OCEAN THERMAL ENERGY CONVERSION
By-
Anik Samaddar and Debanjan Paul,
ME(5th semester), Academy Of Technology

2. INTRODUCTION

3. ● OTEC harnesses the solar energy absorbed by the oceans to
generate electric power.
● It uses the ocean’s naturally available temperature gradient
(thermocline), or thermal energy.
• Oceans collect 80% of the incident solar energy.
•

4. ● Up to 88,000 TWh/yr of power could be generated from
OTEC without affecting the ocean’s thermal structure.
● Unlike wind or solar energy, ocean thermal energy is
available throughout the day, thus eliminating the need to
store energy.

5. STUDY OF OTEC PLANTS

6. CLASSIFICATION
BASED ON CYCLE TYPE
OPEN
CYCLE
PLANT
CLOSED
CYCLE
PLANT
BASED ON LOCATION
LAND
BASED
PLANT
OFF-
SHORE
PLANT

7. CLOSED CYCLE OTEC PLANT
● Low boiling point
working fluid is
used (e.g.
ammonia)

8. WORKING PRINCIPLE
W = QL - (-QH)
ƞ = W/QH = (QL+QH)/QH
QH = THΔSH, QL = TLΔSL
ΔSL = - ΔSH
ƞ = 1 – (TL/TH)
Above: Heat Engine diagram

9. ● Sea water is itself the working fluid
● Desalinated water is a byproduct
OPEN CYCLE OTEC PLANT

10. LAND BASED OTEC PLANT
Schematic diagram
of a land based
OTEC plant.
Notice how it can be
used for irrigation
and refrigeration
besides power
generation.

11. OFFSHORE OTEC PLANT
Right: A concept of a proposed
floating type plant in Puerto Rico
Below: A floating type plant off the
coast at Keahole Point, Hawaii

12. HISTORY

13. Jacques Arsene
d'Arsonval
THE
PIONEERS
Georges Claude

14. Extract from Modern
Mechanics Magazine
(Dec, 1930) featuring a
contemporary article
on the OTEC plant
construction overseen
by Georges Claude in
Matanzas, Cuba

15. Left: OTEC Plant on the ship “Tunisie” off
the Brazil coast (1935)
Right: OTEC test facility at Keahole
Point, Kona, Hawaii (estd. 1974)

16. Left: Pipes used for OTEC plant in Tamil Nadu in 2002
Right: The floating OTEC plant off the TN coast

17. Construction of
the OTEC plant
at Kume Island,
Okinawa in
2013.

18. SCOPE AND POTENTIAL

19. Map representing the thermoclines across the oceans

20. VARIOUS USES OF OTEC

21. COST EFFECTIVE
(cheaper than most other
alternative energy
sources)
NUMEROUS USES
BESIDES POWER
GENERATION
LOW
ENVIRONMENTAL
IMPACT
HUGE RESOURCE
POTENTIAL
(Up to 88,000 TWh/year)
CONSTANT
POWER 24X7
BENEFITS
REDUCES
DEPENDENCE ON
FOSSIL FUELS

22. LIMITATIONS
EXPENSIVE
LIMITED TO AREAS WITH
ANNUAL THERMOCLINE
OF 20°C
POLITICAL
CONCERNS
OVER LOCATION
DISRUPTION OF
ECOSYSTEM

23. FUTURE OF OTEC
Upcoming project
locations:
• The Bahamas, US
• Hainan Island,
China
• Hawaii, US
• Japan
• Virgin Islands, US
• Kiribati
• Andaman & Nicobar
Islands, India
• Martinique, France
• Reunion island,
France

24. REFERENCES AND SOURCES
● Ocean Thermal Energy Conversion - Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion
● How does OTEC work? (ocean thermal energy conversion) - Explain that Stuff
http://www.explainthatstuff.com/how-otec-works.html
● The Energy Debates: Ocean Thermal Energy Conversion
http://www.livescience.com/3155-energy-debates-ocean-thermal-energy-conversion.html
● Ocean Thermal Energy Conversion Basics | Department of Energy
http://energy.gov/eere/energybasics/articles/ocean-thermal-energy-conversion-basics
● OTEC 101 - How Does It Work? - OTE Corporation
http://otecorporation.com/technology/otec-101-how-does-it-work/
● OTEC: The Time Is Now – Lockheed Martin
http://www.lockheedmartin.co.in/us/100years/stories/otec.html
● ocean thermal energy conversion (OTEC) | technology | Britannica.com
https://www.britannica.com/technology/ocean-thermal-energy-conversion