This document discusses ocean thermal energy conversion (OTEC), a renewable energy technology that generates electricity from the temperature difference between warm surface waters and cold deep ocean waters. OTEC works best with a temperature difference of 36°F and is viable in tropical coastal regions. There are two main cycles - open cycle which uses warm water directly and closed cycle which uses a fluid with a low boiling point. Some OTEC plants are currently operating in Japan and France. While OTEC has potential benefits, challenges include dissolved gases coming out of solution in the cold water intake and carefully sealing systems to prevent air inleakage.

2. INTRODUCTION
• A source of renewable energy, uses the heat energy
stored in the earth’s oceans to generate electricity.
• Works best when the temperature difference
between warmer and the colder water is 36 deg F
• Exists in tropical coastal areas roughly between the
tropic of Capricorn and the tropic of cancer.

3. NARRATION
• OTEC was first proposed in
the year 1881 by Jacques
Arsene d’Arsonval a French
physicist.
• The US became involved in
OTEC research in 1974 with
the establishment of the
Natural Energy Laboratory of
Hawaii Authority.

4. OTEC TECHNOLOGIES
Closed cycle
• Use fluid with low boiling point such as ammonia (33 degree C)
to generate electricity.
• Warm sea water is pumped through heat exchanger to vaporize
the fluid.
• Expanding vapour turns the turbo generator .
• Cold water, pumped through a second heat exchanger,
condenses the vapour into a liquid and recycle through the
system.

5. OTEC TECHNOLOGIES
Open Cycle
• Uses warm sea water directly to make electricity.
• The water is first pumped into a low pressure container,
which causes it to boil.
• The pure fresh water steam is further condensed by
exposure to cold ocean water.
Hybrid Cycle
• It combines the features of both above Said technologies.

6. CURRENTLY OPERATING OTEC PLANTS
• In March 2013, Saga University with various
Japanese industries completed the installation
of a new OTEC plant.
• Okinawa prefecture announced the start of
the OTEC operation testing at KUME Island on
April 15,2013.
• In July 2014 DCNS groups partnered with
energy announced NER 300 funding for their
NEMO project.

7. ENVIRONMENTAL IMPACT
HYDRO DYNAMIC MODELING WORK
 In 2010 a computer model was developed to
stimulate the physical oceanographic effects of one
or several 100 MW OTEC.
 The model suggest that OTEC plants can be
configured such that the plant can conduct
continuous operation with variations of
temperatures and nutrients within natural levels.

8. ENVIRONMENTAL IMPACT
BIOLOGICAL MODELING WORK
The discharged nutrients could potentially
increase biological activity when accumulated
in large quantities in the photic zones.
 A biological component was added to the
hydrodynamic computer model to stimulate
the biological response to plumes from 100
MW OTEC plants.

9. TECHNICAL DIFFICULTIES
DISSOLVED GASSES
The direct contact condensers offer significant
disadvantages:
• As cold water rises in the intake pipe, the
pressure decreases to the point where gas begins
to evolve.
• The direct contact heat exchanges may be
justified if a significant amount of gas comes out
of solution.

10. TECHNICAL DIFFICULTIES
SEALING:-
• The evaporator, turbine and condenser must be
carefully sealed to prevent in- leakage of
atmospheric air that can degrade operation.
PARASITIC POWER CONSUMPTION BY EXHAUST
COMPRESSURE:-
• A counter current region increases the gas steam
reaction over which the non condensable gas
steam is passed through after condensation.
• Result is 80% reduction in exhaust pumping
power requirements.

11. ADVANTAGES
•Totally Renewable.
•Generates electricity with no green house effect.
•Produces desalinated water.
DISADVANTAGES
•Needs a large difference in temperatures for best
results.
•Needs to be close to the national grid.
•Plant needs safe location from storms and surf.

12. THANK YOU
PRAKASH JHA
SANJEEV HALDAR
RAJNARAYAN ROY
RISHAV KUMAR SETHIA
KAUSHIK DUARI
SHUBHAM ROY
GOURANGA SAW
MD. SHAMSHER HOSSAIN
RAVI PAL