1. OCEAN THERMAL ENERGY CONVERSION
VIVEK CHAND
I.D : 50489
M.Tech (Electrical Energy system )
2022-2024
2. CONTENTS
INTRODUCTION
HISTORY
OCEAN THERMAL ENERGYCONVERSION
TYPES OF OTEC SYSTEM
APPLICATIONS
BENEFITS & DRAWBACKS OF OTEC
FUTURE PROSPECTS
CONCLUSION
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 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
• Generator
7. TYPES OF OTEC SYSTEM
There are three types of OTEC system:
I. Closed or Anderson Cycle OTEC System
II. Open or Claude Cycle OTEC System
III. 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.
• Boiling point of ammonia is (-33°C).
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.
• Vapor expands and spins a turbine coupled to a turbo-
generator to produce current.
12. HYBRID CYCLE OTEC SYSTEM
• A hybrid cycle combines the features of the closed- and
open-cycle systems.
• Warm 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.
• Vaporized fluid drives a turbine to produce electrical power.
• This fluid leaves the condenser and is pumped to the
evaporator to repeat the cycle.
13. OTEC system applications
• Hydrogen can be produced via electrolysis using electricity
generated by the OTEC process.
• Desalination
Desalinated water can be produced in open- or hybrid-cycle plants
using surface condensers to turn evaporated seawater into potable water.
System analysis indicates that a 2-megawatt plant could produce about 4,300
cubic metres (150,000 cu ft) of desalinated water each day.
14. OTEC system applications
* Aquaculture
Aquaculture is the best-known by product , because it reduces the financial & energy
costs of pumping large volumes of water from deep ocean.
Deep ocean water contains high concentrations of essential nutrients that are depleted in
surface water due to biological consumption. This "artificial upwelling" mimics the natural
upwelling that are responsible for fertilizing and supporting the world's largest marine
ecosystems, and the largest densities of life on the planet.
*Mineral Extraction
The ocean contains 57 trace elements in salts and other forms and dissolved in solution.
In the past, most economic analyses concluded that mining the ocean for trace elements
would be unprofitable, in part because of the energy required to pump the water.
The Japanese investigated the possibility of extracting Uranium. and found
developments in other technologies (especially materials sciences) were improving
the prospects.
15. BENEFITS
Economic Benefits:
• Continuous supply of electricity throughout the year
• Reduced capital expense to power companies
• Life cycle cost savings
Environmental Benefits:
• Reduces dependence on fossil fuels
• Zero emissions and it saves nearly 7000 tons CO2 a year perMW.
16. DRAWBACKS
OTEC produced electricity at present would cost more
than electricity generated from fossils fuels at their current
costs.
No energy company put money in this project because it only
had been tested in a very small scale.
Construction of OTEC plants and lying of pipes in coastal waters
may cause localized damage to reefs and near-shore marine
ecosystem.
17. Current operating Plants of OTEC
In March 2013, Makai installed and operate a 100 kilowatt turbine on the OTEC Heat
Exchanger Test Facility, and connect OTEC power to the grid.
Okinawa Prefecture announced the start of the OTEC operation testing at Kume Island on April
15, 2013. The plant consists of two units; one includes the 50 kW generator while the second
unit is used for component testing and optimization.
In July 2014, DCNS group partnered with Akuo Energy announced NER 300 funding for their
NEMO project. If successful, the 16MW gross 10MW net offshore plant will be the largest
OTEC facility to date.
18. 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.
19. 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 fewyears.
