This power point presentation deals ocean energy conversion technique. This tells how ocean energy convert in to useful energy i.e. in accessible form.

1. ‘OTEC’
Presented By-
Sandeep Kumar Tiwari
12EEE42

2. Content
 Introduction
 Discovery
 Working Principle
 Types
 Advancements
 Cost & Efficiency
 Operating Plant in Present
 Advantages
 Disadvantage
 Future scope
 Conclusion
 References

3. • OTEC, Ocean Thermal Energy Conversion is an energy
technology that converts solar radiation to electric power.
• OTEC utilizes the world’s largest solar radiation
collector.
• The ocean contains enough energy power all of the
world’s electrical needs.
• OTEC is a way to generate electricity using the
temperature difference of sea water at different depth.

4. DISCOVERY
In 1881 Jacques Arsene
d'Arsonval, a French
physicist, was the first to
propose tapping the
thermal energy of the
ocean.
In 1930 Arsonval built an experimental
open cycle OTEC system at Matazas Bay,
Cuba. The system produce 22 KW of
electricity.

5. WORKING PRINCIPLE
OTEC utilizes the ocean’s 20ºC natural thermal
gradient between the warm surface water and the
cold deep sea water(around 1 Km.) to drive a
Rankine Cycle.

6. 2. Fluid pump pressurizes and
pushes working fluid to evaporator
1. Power input to
pumps to start
process
3. Heat addition from
the hot-water source
used to evaporate the
working fluid within
the heat exchanger
(Evaporator)
EVAPORATOR
CONDENSER
WARM SURFACE
WATER 28 C
4. Expanding vapor drive
the turbine, and electricity
is created by a generator
5. Heat
extraction from
cold-water sink to
condense the
working fluid in
the condenser.
TURBINE
GENERATOR
COLD DEEP
WATER
5 C
WORKING FLUID
(LIKE AMMONIA)

8. OPEN CYCLE SYSTEM
 Open-cycle OTEC uses the tropical
oceans' warm surface water to make
electricity.
 Warm seawater is pumped into a flash
evaporator where pressure as low as
0.03 bar cause the water to boil at
temperatures of 22ºC.
 This steam expands through a low-
pressure turbine connected to a
generator to create power.
 The steam then passes through a
condenser using cold seawater from the
depths of the ocean to condense the
steam into desalinized water.

9. CLOSED CYCLE SYSYTEM
A low boiling point liquid such
as ammonia or another type of
refrigerant is used as the
working fluid in a Rankine
cycle.
 The heat from warm seawater
flowing through an evaporator
vaporizes the working fluid.
The vapour expands through a
turbine, then flows into a
condenser where cold seawater
condenses it into a liquid.

10. HYBRID CYCLE SYSTEM
 A hybrid cycle is a combination of both closed and open
cycles where flash evaporator seawater is used as the
closed cycle working fluid.
 This is a cycle wherein, electricity is produced in first
stage followed by water production in second stage.

11. STRUCURAL ADVANCEMENT
 Super-Heater:-In the proposed design, a black metallic plate of
aluminum is installed on the OTEC plant, above the water
surface .
 This plate absorbs maximum solar radiation and gets heated up
to a temperature of 43ºC. This heat is transferred to the
evaporated working fluid by means of connecting rods.
 Pre heater:-The outlet sea water from the evaporator is 12°C
warmer than the working fluid coming out of the condenser.
This fact is used to preheat the working fluid before it advances
into the evaporator which compensates the heat loss from the
heat exchangers.
 It increases the working time of the OTEC plant.
 This preheating increases the efficiency from 3.07 to 3.11 %- a
useful increase.

12. COST & EFICIENCY
 OTEC has the potential to offer global amounts of
energy that are 10 to 100 times greater than other ocean
energy options such as wave power.
 OTEC plants can operate continuously providing a
base load supply for an electrical power generation
system.
 OTEC systems were 1 to 3 % thermally efficient,
below the theoretical maximum 6 and 7 %.
 Using super heater and preheater efficiency is increases.
 Net energy output increases up to 20.3%.
 Using super heater and preheater cost increases up to
21% .

13. Currently operating OTEC plants
 In 2011, Makai Ocean Engineering completed a heat
exchanger test facility at NELHA.
 In 2013, Saga University with various Japanese industries
completed the installation of a new OTEC plant.
 World’s largest Ocean Thermal Energy Conversion Power
Plant in Hawaii of 100kW added to U.S. grid in this year.

14. ADVANTAGES
i. Eco- friendly.
ii. Minimal maintenance costs compared to other power
production plants.
iii.Provide air conditioning to buildings within the OTEC plant
iv. Fresh water - first by-product is fresh water. A small 1 MW
OTEC is capable of producing some 4,500 cubic meters of
fresh water per day, enough to supply a population of 20,000
with fresh water.
v. Open cycle OTEC systems can produce desalinated water
which is very important in third-world countries
vi. Chilled soil agriculture cold seawater flowing through
underground pipes, chills the surrounding soil. Thereby
allowing many plants evolved in temperate to be grown in
subtropics due to temp. difference in the plant roots in cool soil
and plant leaves in warm air.

15. ADVANTAGES
Vii. Mineral Extraction :
 Now a days, in mining the ocean
for trace elements would be
unprofitable as so much energy is
required to pump the large volume
of water needed and because of the
expense involved in separating the
minerals from seawater.
 OTEC plants already pumping the
water, the only remaining
economic challenge is to minimize
the cost of the extraction process.

16. DISADVANTAGES
i. OTEC-produced electricity at present would cost more than
electricity generated from fossil fuels at their current costs.
ii. OTEC plants must be located where a difference of about
20º C occurs year round. Ocean depths must be
available fairly close to shore-based facilities for
economic operation. Floating plant ships could provide
more flexibility.
iii.No energy company will put money in this project because
it only had been tested in a very small scale.
iv.Construction of OTEC plants and lying of pipes in coastal
waters may cause localized damage to reefs and near-shore
marine ecosystems.

17. FUTURE
The fossil fuels will in the near future be
consumed, so we had to find some alternative
energy sources. OTEC is a source, which uses the
renewable solar collector, the sea, instead of an
artificial collector.
The problem is that this investment will be more
expensive than the fossil fuels power plants, and it
will take a long time before anyone will put some
money in this project and outrival the now existing
plants.

18. CONCLUSION
 Ocean thermal energy conversion is a potential source of
renewable energy that creates no emissions. It is fuel free,
has a low environmental impact, can supply pure water for
both drinking and agriculture, can supply refrigeration and
cooling and can provide a coastal community with reliable
energy.
 Research working on mini OTEC plants in laboratories. It
may happen that OTEC systems will one day become a
feasible, efficient and renewable source of energy.

19. REFERENCES
 Luis A. Vega, Economics of Ocean Thermal Energy,
American Society of Civil Engineers,1992 .
 Dr. Hans Krock, Preliminary Analysis of Polymer Heat
Exchangers .
 Maria Bechtel and Erik Netz, OTEC .
 Ruperi Mario, OTEC in Pacific Island.
 www.google.co.in
 Ocean thermal energy conversion – Wikipedia.