This document presents a seminar on underwater windmills. It describes underwater windmills as devices that extract power from tides in a similar way that wind turbines extract power from wind. The main parts of underwater windmills are described as turbines, a gearbox, generator, cables, and support structure. Tidal currents cause the turbine rotor to spin and turn a generator to produce electricity via transmission cables. Examples of existing and planned tidal power installations are provided from locations around the world. Advantages include being a renewable source with low costs and maintenance, while disadvantages include high initial costs and difficulty of installation.

1. A
SEMINAR ON
UNDER WATER WINDMILL
Presented by:
Sandeep.L
USN:4SM09ME043
Mechanical Engineering

2. INTRODUCTION
 What is it ???
 An Underwater windmill like a device that extracts
power from the tides.
Renewable energy technologies are
becoming an increasingly favourable alternative to
conventional energy sources to assuage fossil fuel related
issues. Tidal energy offers a vast and reliable energy
source. This technology is similar to wind energy
technology, with the rotor blades driven not by wind
power but by tidal currents. The gravitational pull of the
moon produces a swift tidal current, which spins the long
blades of the turbine . Which in turn produces electricity
via different parts of underwater windmill . This Energy
derived from the moon that now helps to power a small
arctic village.

3. NAME JUSTIFICATION
 Why it is called as “underwater windmill” ?
 "Basically it's like putting a windmill in the
water," said Bjorn Bekken, a project manager for
Hammerfest Strom.
 Or as it’s looking like a wind mill & are installed
on the ocean floor and large river bed , that
means these are under the water.

4. VIEWS:1

5. VIEWS:2

6. VIEWS:3

7. MAIN PARTS
Turbines
Gearbox
Generator
Cables
support

8. PRINCIPLE OF OPERATION
 In simple a underwater windmill consists of a number of
blades mounted on a hub (together known as the rotor), a
gearbox, and a generator.
 The hydrodynamic effect of the flowing water past the
blades causes the rotor to rotate, thus turning the
generator to which the rotor is connected via a gearbox.
 The gearbox is used to convert the rotational speed of the
rotor shaft to the desired output speed of the generator
shaft.
 The electricity generated is transmitted to land through
cables.

9. RELATED WORK
 The first tidal power station was the Rance tidal power
plant built over a period of 6 years from 1960 to 1966
at La Rance, France. It has 240 MW installed capacity.
 254 MW Sihwa Lake Tidal Power Plant in South
Korea is the largest tidal power installation in the
world. Construction was completed in 2011.
 The first in-stream tidal current generator in North
America (Race Rocks Tidal Power Demonstration
Project) was installed at Race Rocks on southern
Vancouver Island in September 2006. The next phase
in the development of this tidal current generator will
be in Nova Scotia (Bay of Fundy).

10. IMPLIMENTATION
 The company Atlantis Resources is to
install a 50MW tidal farm in the Gulf of
Kutch on India's west coast, with
construction starting early in 2012.The
facility could be expanded to deliver more
than 200MW.
 Projections indicate that the cost of the
initial 50MW farm - to consist of 501MW
turbines - will come in at about $150m.
 The current timescale has the project's
final engineering plans completed by the
end of this Year 2013.

11. FUTURE WORK
 The contract for an 812 MW tidal barrage near
Ganghwa Island (South Korea) north-west of
Incheon has been signed by Daewoo. Completion is
planned for 2015.
 A 1,320 MW barrage built around islands west of
Incheon is proposed by the South Korean
government, with projected construction start in
2017.
 In New York City, 30 tidal turbines will be installed
by Verdant Power in the East River by 2015 with a
capacity of 1.05MW. The contract for an 812 MW tidal
barrage near Ganghwa Island (South Korea) north-
west of Incheon has been signed by Daewoo.
Completion is planned for 2015.
 A 1,320 MW barrage built around islands west of
Incheon is proposed by the South Korean
government, with projected construction start in
2017.

12. ADVANTAGES:
The advantages of under water windmill is
much more than the disadvantages:-
 Uses Tidal energy ,which is a clean and
renewable source of energy
 Have lesser impact on the environment
 Low running cost
 Long lifetime with little maintenance
 Reduces the dependence upon fossil fuels

13. DISADVANTAGES:
 The initial cost is too high
 Very difficult to install
 The blade must be coated to avoid
corrosion
 Special type material must have to be
used for blade

14. GLOBAL RESOURCES
It is widely agreed that, tidal stream energy capacity
could exceed 120GW globally .
The UK has one of the largest marine energy resources
in the world.

15. CONCLUSION
 Tides play a very important role in the formation of global climate as
well as the ecosystems for ocean habitants. At the same time, tides are
a substantial potential source of clean renewable energy for future
human generations. Depleting oil reserves, the emission of greenhouse
gases by burning coal, oil and other fossil fuels, as well as the
accumulation of nuclear waste from nuclear reactors will inevitably
force people to replace most of our traditional energy sources with
renewable energy in the future . Tidal energy is one of the best
candidates for this approaching revolution. Development of new,
efficient, low-cost and environmentally friendly hydraulic energy
converters suited to free-flow waters. This type of machine, moreover
,can be used not only for multi-megawatt tidal power farms but also for
mini-power stations with turbines generating a few kilowatts. Such
power stations can provide clean energy to small communities or even
individual households located near continental shorelines, straits or on
remote islands with strong tidal currents.

16. REFERENCES
 http://www.marineturbines.com/
 http://www.renewable-solarenergy.com/tidal-
energy-power.html
 International Energy Agency, World Energy
Outlook 2007.
 Prandle, D., Simple theory for designing tidal
power schemes, Advances in Water Resources,
1984.
 Sheth, S. and M. Shahidehpour, Tidal Energy in
Electric Power Systems, in Power Engineering
Society General Meeting, 2005.
 http://www.tidalenergyltd.com/technology.htm