The Temperature difference between cooler deep water & warmer surface water of seawater to run a heat engine and produce electricity. Known as OTEC.

1. Presentation
by
 Rakib
Hossa
in
ID:
11.02.
08.04
7

2. What is ocean thermal energy conversion
(OTEC)
 Temperature difference between cooler deep & warmer
surface to run a heat engine and produce electricity.
 Distance between surface & cooler deep should be
1000m.
 Mainly rankine cycle is used in the process .
 Refrigerants used- ammonia or R-134a .

3. Ocean thermal energy conversion

4. Process of OTEC
 Cycles in OTEC >>>
 Open cycle
 Close cycle
 Hybrid cycle

5. Open cycle
Warm surface water is
used directly.
First surface water is
pumped for boiling.
Produced steam drives
to turbine connected to
generator.
Steam is condensed by
the cold temperature from
deep water.

6. closed cycle
Closed cycle
•Uses fluid with low
boiling point.
•Surface water
pumped by heat
exchanger to
vaporize fluid.
•Fluid vapor turns the
turbo generator.
•Vapor condensed by
the flow of cold water
by 2nd heat
exchanger.

7. Hybrid cycle
Combination of closed
& open cycle.
Evaporation is same
as open cycle.
Working fluid
vaporized as closed
cycle.
 Vaporized fluid drives
turbine.

8. Working fluid
 Popular choice – ammonia >> easy availability >> but
toxic & flammable.
 Fluorinated carbon – CFC or HCFC >> not toxic or
flammable >> destroy ozone layer.
 Hydrocarbons >> highly flammable .

9. Thermodynamic efficiency
 Temperature difference between surface and deep water
is high in tropic , helps to run heat engine.
 It is 10 to 100 times more efficient than wave power of
ocean.
 It can supply continuous base load supply to power
generation system.
 It is considered as emerging technology.

10. Evolution of OTEC
 1880 >> 1st attempt to develop OTEC .
 1930 >> 1st OTEC plant built in Cuba . (22 kw) ,
destroyed by storm later .
 1967 >> 1st use of closed cycle of rankine system .
 Japan is the major contributor of OTEC since 1970.
 2002 >> OTEC plant in tamilnadu , India.
 OTEC plant is increasing day by day .

11. Different types of OTEC sites
 Land sites >>
near sea shore
Advantages >> do not need { sophisticated mooring, long cable,
extensive maintenance}
 Shelf based >>
Far from surf zone, near to cold water.
Disadvantages >> difficult product delivery, long cable needed,
more expensive.
 Floating sites >>
Operate off shore, optimal for large system.
Disadvantage >> complicates power delivery , possibility of
damage of cable, difficult to maintain & repair.

12. Related activities other than power generation
 Air conditioning
 Chilled soil agriculture
 Hydrogen production
 Producing distilled water
 Aqua culture
 irrigation

13. Figure of related activities other than
power generation

14. Cost & Economics
 It is a renewable energy .
 One study shows that its cost is US $ 0.07 per kilowatt –
hour.
 Beneficial fact : lack of waste products and fuel
consumption.
 Supplemental use of sea water.
 Many more useful fact other than power generation.

15. Environmental impact
 Carbon dioxide dissolve
 Unbalance ecological system
 Accidental condition of closed cycle
 Effect in commercial fishing

16. Conclusion
We need 6500 MW electricity per day , but we are
producing only 5500 MW .As it’s a low cost harmless
renewable energy to produce electricity , it could be
bless for our country.
For more info please visit ;
www.OTEC.org

17. Thank you all
Any
question??