Renewable energy has environmental, economic, and security benefits. Three types of ocean renewable energy are tidal, wave, and ocean thermal energy. Tidal energy works like hydropower by trapping sea water with dams during high tide to power turbines when the tide drops. Ocean thermal energy uses the temperature difference between warm surface water and cold deep water to power a heat engine and generator.

2. “The more we use renewable energy, the
more we benefit the environment,
strengthen our energy security, create jobs
locally, and help improve our economy. “
(NREL, USA)

3. • Still in experimental stage, not common
• Three types:
– Waves energy
– Tidal energy
– Ocean thermal energy

4. When the air flows,
turbine is turned
and it would drive
the generator.
Electricity is
produced.

5. • Tidal energy
– similar to hydropower plant
• dam traps the sea water when high tide
• when tide drops, water flow turns the turbine and drives the
production of electricity of generator
• Ocean thermal energy
– application of the temperature difference of sea water

6. • Oceanic Thermal Energy
Conversion
• OTEC utilizes the ocean’s
20ºC natural thermal
gradient between the warm
surface water and the cold
deep sea water to drive a
Rankine Cycle
• OTEC utilizes the world’s
largest solar radiation
collector - the ocean. The
ocean contains enough
energy power all of the
world’s electrical needs.

8. 1. Power input to pumps
to start process
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.
Cycle begins
again
Return to step
2
3. Heat addition from the hot-
water source used to evaporate
the working fluid within the
heat exchanger (Evaporator)

9. System Boundary
Power Plant
Control
System
Warm Seawater is
External Input
Cold Seawater is
External Input
Power to Power
Plant is System
Output

10. Controls
•Water Pump
•Fluid Pump
•OTEC CPU
•Turbine
•Generator
•Heat Exchangers
•Pipes
•Working fluid
(Noise Factors)
•Temperature
•Sea state
•Weather
•Corrosion
(Output Functions)
•Power
•Water
(Input Signals)
•Water
•Startup Power
OTEC
System

11. 1. Clean energy production
2. Fresh water production
3. Continuous power
4. Energy independence
5. Aquaculture enterprises
6. Air-conditioning/refrigeration
7. Mineral extraction

12. • Low efficiency
• High capital costs for initial construction
• Potential ecological consequences
• Siting considerations
• Must operate in a corrosive marine
environment