3. INTRODUCTION
The sources for 90% of the electric energy generated
today are non-renewable.rThe depletion of the finite
resources, environmental pollution, global warming
became
more apparent near the end of the 20th century.y. There
are three types of renewable energy sources: solar,
wind, and waterpower. Both solar and wind power are
drastically
affected by weather variations, while tidal power varies
little when the weather changes
4. What is TIDAL ENERGY
Tidal power, also called tidal energy,
is a form of hydropower that converts
the energy of tides into useful forms
of power - mainly electricity.
Although not yet widely used, tidal
power has potential for
future electricity generation. Tides
are more predictable than wind
energy and solar power
5. What is tide ?
Tides are the rise and fall of sea levels caused
by the combined effects of the gravitational
forces exerted by the Moon and the Sun and
the rotation of the Earth.
Tide are two type
1 spring tide
2 neap tide
6.
7.
8. Energy from tide can be generate in
three ways
TIDEL BARRAGE
TIDE MILL
TIDEL STREAM
9. Tide mill
The generation of energy from the tides is not a
new idea. Mills, which used tidal flows in bays
and estuaries to drive machinery to grind . were
used in medieval times This, and changing labour
markets following the First World War, resulted in
traditional tide mills becoming rare and of
historical interest only.
10.
11. Tidal barrage
A tidal barrage is a dam-like structure used to capture
the energy from masses of water moving in and out
of a bay or river due to tidal forces a tidal barrage first
allows water to flow into a bay or river during high
tide, and releasing the water back during low tide.
This is done by measuring the tidal flow and
controlling the sluice gates at key times of the tidal
cycle. Turbines are then placed at these sluices to
capture the energy as the water flows in and out.
13. The Rance Tidal Power Station is the
world's first tidal power station and also
the world's second biggest tidal power
station. Opened on the 26th November
1966, With a peak rating of
240 Megawatts, generated by its
24 turbines it supplies 0.012% of the
power demand of France.
14.
15. TIDAL STREAM
The technology involved is very similar to
wind energy, but there are some differences.
Water is 800 times denser than air and has a
much slower flow rate this means that the
turbine experiences much larger forces and
moments. This results in turbines with much
smaller diameters
16. TYPE OF TIDAL TURBINE
VETICAL AXIS
TURBINE
HORIZONTAL AXIS
TURBINE
VENTURI TYPE TURBINE
17. Vertical axis turbine
The rotational axis of the
system is perpendicular to the
direction of water flow.
Vertical axis turbines can
harness energy from flows in
any direction and may be
more efficient than
horizontal axis turbines in
low flow conditions.
However, horizontal axis
turbines have greater
efficiency and survivability in
strong flows
18. Horizontal axis turbine
A horizontal axis turbine has the
traditional form of “fan” type
system familiar in the form of
windmills and wind energy
systems. As water is approximately
800 times denser than air and has
a much slower flow rate, water
turbines experience much larger
force sand moments than wind
turbines. This leads to the
development of turbines with
smaller diameters and blades with
different designs.
19. They can operate in slow
moving water with a
smaller turbine at sites
where large turbines are
restricted. A shroud of
suitable geometry can
increase the flow velocity
across the turbine by 3 to 4
times the open or free
stream velocity.
20.
21. Advantage of tidal energy
Once you've built it, the energy is free because it comes
from the ocean's power
A plant is expected to be in production for 75 to 100 years
There is no carbon dioxide or any other by-products
released. It produces no greenhouse gases or other waste.
Tides are definitely predictable. There are two tides every
day and they can be relied on. So the electricity supply is
constant.
22. DISADVANTAGE OF TIDAL ENERGY
Expensive to construct. Limited construction site.
A barrage is very expensive to build, and affects a very wide
area.. Barrage systems require salt resistant parts and lots of
maintenance
The dams and barrages sometimes interfere with shipping.
Only provides power for around
10 hours each day, when the tide is actually moving in or out.
There are few suitable sites for tidal barrages.
23. conclusion
Tidal energy is a kind of renewable energy with
large potential. It has many advantages over
solar and wind energy. For example the
availability of tidal energy is highly predictable
and not subject to the impact of weather
condition. The energy density of tides is also
higher than solar and wind energy. However, the
high demand in technology and capital
investment has hindered the development of tidal
energy so that the tidal energy projects are much
less than those of solar and wind energy.