Transcript japan - HarnessingOceanEnergy

JAPAN
OCEAN WAVE TECHNOLOGIES
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Company/Organization – Sanze shoreline gully
Technology/Plant Name - Sanze shoreline gully
Technology Genre - OWC - Near-shore
Power take-off system – Air Turbine
Shoreline gullies are naturally tapered channels, and an oscillating water column
(OWC) at the head of such a gully is exposed to higher wave power densities than
those found at the gully’s mouth. Systems based on this principle have been built in
several countries, primarily for testing pneumatic turbine designs. The Japanese version
was a 40kW onshore unit that operated for six months at Sanze on the west coast of
Japan before it was taken out of service in 1984.
OCEAN WAVE TECHNOLOGIES
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Company/Organization – Ministry of Transport
Technology/Plant Name - The Sakata OWC
Technology Genre - OWC - Near-shore
Power take-off system – Air Turbine
Another Japanese onshore fixed OWC system is based on caissons placed side-by-side
in a breakwater configuration. Such an OWC has been developed by the Japanese
Ministry of Transport under the direction of Yoshimi Goda & a 60 kW prototype has
been installed as part of a new offshore breakwater built at Sakata Port on the west
coast of Japan. The breakwater consists of a row of caissons on a rubble mound
foundation, one of the caissons being built with a “curtain wall” that forms the OWC
capture chamber.
OCEAN WAVE TECHNOLOGIES
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Company/Organization – JAMSTEC
Technology/Plant Name - Mighty Whale OWC
Technology Genre - OWC – Floating
Power take-off system – Air Turbine
The Marine Science & Technology Centre of Japan launched the world’s largest
offshore floating wave power device in July 1998, and the full-scale prototype will be
tested until the year 2000.
This floating device, called the Mighty Whale, converts wave energy to electricity. The
device measures 50 metres long by 30 metres wide, and uses waves in the Pacific
Ocean to drive three air turbines (one with a rated output of 50 kW + 10 kW and two
of 30 kW) on board the platform, to generate 120 kW of electricity.
OCEAN WAVE TECHNOLOGIES
Mighty Whale OWC
OCEAN WAVE TECHNOLOGIES
After being towed to its mooring about 1.5 km from the mouth of Gokasho Bay, the
Mighty Whale was anchored to the bottom of the sea (about 40 m deep) with six
mooring lines; four lines on the seaward side and two on the lee side. Mooring lines are
designed to withstand typhoon winds, and the unit is designed to handle waves of 8 m.
The Mighty Whale converts wave energy to electricity by using oscillating columns of
water to drive air turbines. Waves flowing in and out of the air chambers at the
‘mouth’ of the Mighty Whale make the water level in the chambers rise and fall. The
water forces air into and out of the chambers through nozzles on the tops of the
chambers. The resulting high-speed air-flows rotate air turbines which drive the
generators. The Mighty Whale can be remotely controlled from on-shore. In the
demonstration prototype, the energy produced is mostly used by the instruments
carried on board; any surplus is used to charge a storage battery or, when this is fully
charged, is used by a loading resistor. A safety valve protects the air turbines from
stormy weather by shutting off the flow of air if the rotation speed of the turbines
exceeds a predetermined level. So that it can be used in the future to improve water
quality, the prototype is also equipped with an air compressor to provide aeration.
Because it has absorbed and converted most of the energy in the wave, the Mighty
Whale also creates calm sea space behind it, and this feature can be utilised; for
example, to make areas suitable for fish farming and water sports. The structure of the
Mighty Whale itself can be used as a weather monitoring station, a temporary mooring
for small vessels or a recreational fishing platform.
THERMAL GRADIENT TECHNOLOGIES
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Company/Organization – Saga University
Technology/Plant Name - Hybrid OTEC
Technology Genre - OTEC
Power take-off system – Other
A hybrid cycle combines the features of both the closed-cycle and open-cycle systems.
In a hybrid OTEC system, warm seawater enters a vacuum chamber where it is flashevaporated into steam, which is similar to the open-cycle evaporation process. The
steam vaporizes the working fluid of a closed-cycle loop on the other side of an
ammonia vaporizer. The vaporized fluid then drives a turbine that produces electricity.
The steam condenses within the heat exchanger and provides desalinated water.
The electricity produced by the system can be delivered to a utility grid or used to
manufacture methanol, hydrogen, refined metals, ammonia, and similar products. Now
let's take a closer look at some of the main components of an OTEC system—
specifically, the heat exchangers, evaporators, turbines, and condensers.
THERMAL GRADIENT TECHNOLOGIES
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Company/Organization – Tokyo Electric, Kyushu Electric, Saga University
Technology/Plant Name - Closed-Cycle OTEC
Technology Genre - OTEC
Power take-off system – Other
In the closed-cycle OTEC system, warm seawater vaporizes a working fluid, such as
ammonia, flowing through a heat exchanger (evaporator). The vapor expands at
moderate pressures and turns a turbine coupled to a generator that produces
electricity. The vapor is then condensed in another heat exchanger (condenser) using
cold seawater pumped from the ocean's depths through a cold-water pipe. The
condensed working fluid is pumped back to the evaporator to repeat the cycle. The
working fluid remains in a closed system and circulates continuously.
JAPAN
Made By –
 Narender – IX-A
 Suman – IX-A
 Sanpreet – IX-A
 Monu – IX-A
 Komal Singh – IX-A
 Jagir Singh – IX-A
 Isha – IX-A
 Shalu – IX-A
 Rohit – IX-A