2. History
History
Sources differ, but it's generally
Sources differ, but it's generally
agreed that forms of tidal
agreed that forms of tidal
energy were used as early as
energy were used as early as
the eighth century A.D.
the eighth century A.D.
The first recorded uses of tidal
The first recorded uses of tidal
energy were on European
energy were on European
coasts.
coasts. Early tidal mills sat on a pond
Early tidal mills sat on a pond
filled by the incoming tide that
filled by the incoming tide that
went through a sluice, and
went through a sluice, and
emptied when the tide went out
emptied when the tide went out
through a water wheel.
through a water wheel.
The turning of the water wheel
The turning of the water wheel
provided power to mill grain.
provided power to mill grain.
3. Present
Present
The newest technology of the source of
The newest technology of the source of
tidal energy is now used for electricity.
tidal energy is now used for electricity.
Now a days hydroelectric power is
Now a days hydroelectric power is
becoming more common.
becoming more common.
It works by tidal waves going through
It works by tidal waves going through
the generator converting the energy of
the generator converting the energy of
the wave into power with out any
the wave into power with out any
harmful green house gases.
harmful green house gases.
There are many different ways of
There are many different ways of
creating tidal energy.
creating tidal energy.
One way is tidal generator.This
One way is tidal generator.This
machine has special blades so nothing
machine has special blades so nothing
gets caught.
gets caught. Another type is a barrage witch is
Another type is a barrage witch is
becoming more common in rivers.
becoming more common in rivers.
The two big tidal power plants are now
The two big tidal power plants are now
in France and Russia.
in France and Russia.
5. TidalTurbines
TidalTurbines
Tidal turbines use similar technology to
Tidal turbines use similar technology to
wind turbines, although their blades are
wind turbines, although their blades are
much shorter and stronger. (So a good
much shorter and stronger. (So a good
way to think of them is as underwater
way to think of them is as underwater
windmills).
windmills).Basically the water currents turn the
Basically the water currents turn the
turbines, which in turn activate a
turbines, which in turn activate a
generator that produces electricity.
generator that produces electricity.
These systems work best where there
These systems work best where there
are very strong tidal zones (Norwegian
are very strong tidal zones (Norwegian
and British coastlines.)
and British coastlines.)
The upfront cost of these tidal stream
The upfront cost of these tidal stream
systems is very high and also installation
systems is very high and also installation
and maintenance is difficult.
and maintenance is difficult.
But it’s still cheaper and has less
But it’s still cheaper and has less
environmental impact than any another
environmental impact than any another
tidal system.
tidal system.
6. TidalBarrages
TidalBarrages
Tidal barrages are very similar to the Dams in
Tidal barrages are very similar to the Dams in
hydroelectric plants, except that they are much
hydroelectric plants, except that they are much
larger as they are built across an estuary or bay.
larger as they are built across an estuary or bay.
The tidal range (difference between high and low
The tidal range (difference between high and low
tide) needs to be in excess of five metres for the
tide) needs to be in excess of five metres for the
barrage to be workable.
barrage to be workable.
As the tide comes in, water flows through the dam
As the tide comes in, water flows through the dam
into the basin.Then when the tide stops the gates
into the basin.Then when the tide stops the gates
are closed, which traps the water in the
are closed, which traps the water in the
basin/estuary.
basin/estuary. As the tide goes out gates in the dam which
As the tide goes out gates in the dam which
contain turbines are then opened and the flowing
contain turbines are then opened and the flowing
water passes through the turbines, thus
water passes through the turbines, thus
generating energy.
generating energy.
Tidal barrages have very high infrastructure costs
Tidal barrages have very high infrastructure costs
and are very damaging on the local environment.
and are very damaging on the local environment.
Also construction of such dams is a very lengthy
Also construction of such dams is a very lengthy
project. A good example of this is the La Rance
project. A good example of this is the La Rance
barrage in France which took over five years to
barrage in France which took over five years to
build (it’s the largest tidal power station in the
build (it’s the largest tidal power station in the
world.)
world.)
7. TidalLagoons
TidalLagoons
Tidal Lagoons are similar to
Tidal Lagoons are similar to
barrages but have a much
barrages but have a much
lower cost and impact on the
lower cost and impact on the
environment.
environment. They are self contained
They are self contained
structures cut off from the
structures cut off from the
rest of the sea.
rest of the sea. It works in pretty much the
It works in pretty much the
same way as a tidal barrage
same way as a tidal barrage
as when the tide rises the
as when the tide rises the
lagoon fills and when it falls
lagoon fills and when it falls
the water is then released
the water is then released
through the turbines.
through the turbines.
8. Howitworks
Howitworks
Turbines are placed under the sea in
Turbines are placed under the sea in
areas which have high tidal movement.
areas which have high tidal movement.
These turbines are designed to
These turbines are designed to
capture the energy produced by the
capture the energy produced by the
tidal movement and is then
tidal movement and is then
transformed into electricity.
transformed into electricity.
The tide moves a huge amount of water
The tide moves a huge amount of water
twice each day.
twice each day.
Although the energy supply is reliable
Although the energy supply is reliable
and plentiful, converting it into useful
and plentiful, converting it into useful
electrical power is not easy.
electrical power is not easy.
There are eight main sites around
There are eight main sites around
Britain where tidal power stations
Britain where tidal power stations
could usefully be built.
could usefully be built.
Only around 20 sites in the world have
Only around 20 sites in the world have
been identified as possible tidal power
been identified as possible tidal power
stations.
stations.
9. Cost
Cost
It’s Very inexpensive in the
It’s Very inexpensive in the
long run.
long run. Most of the cost comes
Most of the cost comes
from building it.
from building it.
It cost about 5-10 billion
It cost about 5-10 billion
dollars.
dollars. Most companies don't want
Most companies don't want
to invest because there
to invest because there
aren't immediate results.
aren't immediate results.
80% of kinetic energy from
80% of kinetic energy from
the waves can be
the waves can be
converted into usable
converted into usable
energy
energy
10. Advantagesvs.
Advantagesvs.disadvantages
disadvantages
Advantages
Advantages The energy is free
The energy is free
- no fuel needed,
- no fuel needed,
no waste
no wasteproduced.
produced. Most designs are
Most designs are
inexpensive to
inexpensive to
operate and
operate andmaintain.
maintain. Waves can
Waves canproduce a great
produce a great
deal of energy.
deal of energy.
Tides are
Tides arepredictable
predictable There are minimal
There are minimal
environmental
environmental
impacts.
impacts.
Disadvantage
Disadvantagess
Depends on the waves – -
Depends on the waves – -
sometimes you'll get loads of
sometimes you'll get loads of
energy, sometimes nothing
energy, sometimes nothing
The actual construction is
The actual construction is
very expensive
very expensive
Needs a suitable site, where
Needs a suitable site, where
waves are consistently
waves are consistently
strong.
strong. Must be able to withstand
Must be able to withstand
very rough weather.
very rough weather.
Disturbance or destruction
Disturbance or destruction
of marine life
of marine life Degradation of scenic ocean
Degradation of scenic ocean
front views from wave
front views from wave
energy devices located near
energy devices located near
or on the shore, and from
or on the shore, and from
onshore overhead electric
onshore overhead electric
transmission lines.
transmission lines.
The dams become unusable
The dams become unusable
after 50-100 years
after 50-100 years