This document discusses Ocean Thermal Energy Conversion (OTEC), which utilizes the temperature difference between warm surface ocean waters and cold deep ocean waters. It was first proposed in 1881 as a way to generate electricity. There are two types of OTEC systems - open cycle systems which use the evaporation and condensation of seawater to drive turbines, and closed cycle systems which use a working fluid like ammonia. OTEC is a renewable source of energy but high capital costs currently make electricity from OTEC more expensive than fossil fuels. However, as fossil fuels are depleted, OTEC is a promising alternative energy source that can also produce fresh water.
2. Introduction to OTEC
•The oceans cover a little more than 70 percent of
the Earth's surface.
•This makes them the world's largest solar energy
collector and energy storage system.
•On an average day, 60 million square kilometers
(23 million square miles) of tropical seas absorb an
amount of solar radiation equal in heat content to
about 250 billion barrels of oil.
3. Discovery
• In 1881 Jacques
Arsene dArsonval ,a French
physicist ,was the first to
propose tapping the thermal
energy.
•Arsonval In 1930, in the ocean
built an Experimental
open cycle OTEC system at
Matazas Bay, Cuba.
4. OTEC PROCESS:
•OTEC utilizes the oceans
28⁰C natural thermal
gradient between the
warm surface water and
the cold deep water .
•Oceans surface waters
acts as heat source the
cold water at 1,000
meters.
6. OPEN CYCLE SYSTEM:
•Open-cycle OTEC uses the tropical
ocean’s Warm surface water to make
electricity.
when warm seawater is placed in a
low-pressure container, it boils.
•The expanding steam drives a
low-pressure turbine attached to
an electrical generator.
•The steam , which has left its
salt behind in the low-pressure
container , is almost pure fresh
water .It is condensed back into a
liquid by exposure to cold
temperature from deep-ocean water.
water
7. Closed Cycle System:
Closed-cycle systems( Rankine ) use
fluid with a low-boiling point , such as
ammonia , to rotate a turbine to
generate electricity .Warm surface
is pumped through a heat exchanger
where the low-boiling point fluid is
vaporized . The expanding vapor turns
the turbo-generator. Then , cold , deep
seawater-pumped through a heat
exchanger –condenses the vapor back
into a liquid , which is then recycled
through the system
8. ADVANTAGES:
•Eco- friendly.
•Minimal maintenance cost.
•Fresh water – first –by product is fresh water is capable
of producing 4,500 cubic meters of fresh per day , enough
to supply a population of 20,000 with fresh water.
•Mineral extraction – helps in mining ocean water for
57 trace economic analysis have suggested .
9. DISADVANTAGES:
• OTEC plants must be located where a difference
of about 28⁰C occurs year round.
•OTEC- produced electricity at present would cost
more than electricity generated from
fossil fuels at their current costs.
10. FUTURE:
The fossil fuels in the near future be consumed ,
so we have to find some alternative
energy sources .OTEC is a source , which uses the
renewable solar collector .
