Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Background and Prior Art
There are a number of methods available when it comes to generating power from
tidal
action; a few of which can be briefly summarized.
One option involves the use of impoundment ponds. This entails the capturing
and storing
of water. The water is released once there is a significant height
differential between the stored
water and the source of that incoming water, be it an ocean or bay etc. When
the stored water
is released back to the source, it passes through turbines which spin and
generate electricity.
There are a number of these power plants in operation around the world and
which provide
clean renewable energy. While these power plants may be efficient at
generating electricity,
they can also adversely affect local ecosystems such as estuaries. New
proposed plants also
face this issue. Another obstacle that prevents the widespread adoption of
this type of tidal
energy production is that there are not enough suitable locations near
population centres
where these tidal power plants can be viably built.
Ramez Atiya ¨ Patent ¨ US 6967413 B2 seeks to address this issue by locating
the
impoundment pond offshore or along the coast. An examination of this idea
appears to make
the cost prohibitive versus the amount of power generated.
In addition, this patent at Figure 9, "shows the tidal wall configured so as
to funnel streams
into the turbine/generator thus generating energy from tidal currents." It
also states, "The Tidal
Energy System can be configured to extract energy from the kinetic energy of
tidal flows (see
Fig. 9) Where applicable, this configuration adds to the generating capacity
of the Tidal Energy
System." Italics added
Figure 2 of that patent illustrates what this structure would look like
without this added
feature and it can be discerned how the structure would function with this
modified
embodiment in place. Since the water is being impounded, the height
differential at high tide
would not be significantly different from the water outside the structure. As
a result, it is
evident that patent US 6967413 B2 is fundamentally different from what is
proposed in this
new patent.
Another method of generating energy from tides involves locating turbines in
the pathway
of tidal currents. While this approach has shown some promise, there are a
number of
drawbacks which include finding suitable locations; construction and
maintenance costs versus
the potential power output and the possible impact these turbines may have on
aquatic
animals.
Derek Foran ¨ Patent ¨ CA 2644792 Al tries a different approach, whereas a
structure is
built offshore or possibly at shore if certain conditions are met, and the
currents from the
flooding and under most circumstances the ebbing tides are funneled into a
central area where
the turbine(s) are located.
As with other types of structures already in use, it is possible to generate
electricity with this
method. The primary reasons as to why this structure is not being built
worldwide appears to
revolve around the issues of feasibility and practicality. It is proposed that
the structure does
not necessarily have to be permanent such as other types of impoundment ponds
and that it,
"is relatively easy to dissemble."
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It also states that the walls of the structure could be made of non-corroding
sheet metal or
possibly of resistant flexible sheets made of a heavy woven synthetic material
or if local
conditions warrant ¨ reinforced concrete. The patent also states that, "the
containment walls
of the Tidal Energy Structure do not have to withstand as much force as those
of impoundment
ponds because there is no water differential. Due to this, the walls of the
Tidal Energy Structure
do not have to be as thick which saves on construction and material costs.
Italics added
In view of the foregoing, it is evident that prior processes and inventions
while having some
merit, also face many obstacles including environmental, location and
feasibility requirements.
The Tidal Energy Power Plant that is proposed in this new patent takes all
these obstacles
into account. It meets the criteria as set out in the Patent Act as it is a
substantial measurable
improvement over existing ideas, while also offering the best overall solution
for meeting the
energy needs for today and tomorrow.
Analogy
Due to the moon's gravitational influence on Earth's oceans, there is an
approximate 1
metre surge of water that is generated in the deep oceans and traverses the
Earth at
approximately 1600 km/hr. A lunar day is close to being 24 hours and 50
minutes. During this
period, there will be 2 high tides that will pass a fixed point in the deep
ocean. (The moon has
an effect on all the Earth including generating smaller tides on smaller
bodies of water. The
Sun's gravitational influence on Earth is somewhat less than the moon.)
If the surface of the entire Earth was composed of water; the 1 metre surge
would circle the
Earth continuously. It's the presence of land that stops the tides. Even as
the 1 metre tidal
surge enters more shallow water, there is still a tremendous amount of tidal
energy that
reaches the coast. This 1 metre tidal surge under natural conditions is
funneled into areas such
as The Bay of Fundy, where tides can reach more than 10 metres high.
The Tidal Energy Power Plant seeks to replicate this phenomenon with an
engineered
system to capture this massive natural force, which when funneled under
controlled conditions,
results in a noticeable height differential from the surrounding water and
which can then be
used to generate electricity as it passes through turbines.
Since the 1 metre tidal surge is moving at approximately 1600 km/hr., it is
possible to
estimate how much water would flow past a 1 kilometre wide stretch of deep
ocean.
1 metre (deep) x 1600 kilometres (1,600,000 metres) x 1 kilometre wide (1000
metres)
= 1,600,000,000 cubic metres per hour
Divide 1,600,000,000 by 3600 (60 minutes x 60 seconds)
= Approximately 444,444 cubic metres per second
To illustrate ¨ if there was a 1 kilometre wide channel at an ocean coastal
area, that had a
regular 1 metre high tide and which was 5 kilometres long and 50 metres deep,
leading to a
body of water that was 10,000 square kilometres in size, (100 kilometres x 100
kilometres)
This 1 kilometre wide channel when opened up would have the ocean tidal
currents flowing in
at the high tide mark somewhere near to that number cited above ¨444,444 cubic
metres per
second. (Friction and other losses would have to be taken into account)
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As a comparison: the water approaching Niagara Falls in peak season can be as
much as
6,400 cubic metres per second. During the summer months, at least 2,800 cubic
metres per
second traverses the falls, some 90% of which goes over the Horseshoe Falls,
while the balance
is diverted to hydroelectric facilities. These power plants located in the
Province of Ontario and
the State of New York generate upwards of 4.5 gigawatts of electricity.
This is to illustrate the potential pressure that exists along a regular ocean
coastline that
experiences regular tides.
Now if the 1 kilometre wide channel in the illustration was instead turned
into the Tidal
Energy Power Plant and the water was subsequently funneled as the tide came in
through the
wide opening. At the narrow end, the height of the water would be
significantly higher as
compared to the water outside the structure. It is the water inside the
structure that enters the
turbines to generate electricity and is then dispersed back into the water
surrounding the Tidal
Energy Power Plant.
Detailed description of the invention
With reference to the drawings and in particular FIG. 1,2; these drawings are
subject to
change based on actual local conditions.
FIG. 1 depicts the Tidal Energy Power Plant as a shore based facility. It can
also be built
offshore.
The depth here 1, can vary based on local conditions but the wide opening
needs to be at a
minimum depth so that as much of the tidal force as possible enters the
structure. The wide
opening should if possible face the incoming tidal currents, but local
conditions may warrant an
offset orientation.
The walls 2, are built to withstand the containment of thousands of cubic
metres of water
above sea level and are built to be above the high tide level. The walls can
be built of concrete,
stone, metal or any other suitable substance.
The walls 3, gradually increase in height above sea level as the walls
approach the narrow
end. The height will be based on the tidal currents being funneled and the
height differential
expected as compared to the surrounding water outside the Tidal Energy Power
Plant. Storm
surges along with safety considerations etc. will have to be taken into
account when final
designs are approved.
The turbines 4, are designed to handle the enormous pressure and these
turbines can also
be stacked and be both below the normal outside high tide level and above the
outside high
tide level.
The bottom floor 5, of the Tidal Energy Power Plant can slope upward toward
the turbines if
it is deemed feasible.
Netting and/or pylons 6, will be installed to help prevent aquatic animals
from entering the
structure. Further barriers such as nets can surround the perimeter of the
whole structure.
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A platform 7, where transmission lines can exit the facility. Facilities for
the production of
hydrogen along with buildings and offices for the maintenance of the plant
etc. can be located
here. These facilities can also be built on shore. Local conditions will
dictate where these
facilities are actually located. Below this platform are the conduits for the
water to return to the
surrounding water outside.
FIG. 2 depicts an offshore facility although it can also be built at or near
shore with the
shipping dock facilities moved or removed.
The depth here 1, can vary based on local conditions but the wide opening
needs to be at a
minimum depth so that as much of the tidal force as possible enters the
structure. The wide
opening should if possible face the incoming tidal currents, but local
conditions may warrant an
offset orientation.
The walls 2, are built to withstand the containment of thousands of cubic
metres of water
above sea level and are built to be above the high tide level. The walls can
be built of concrete,
stone, metal or any other suitable substance.
The walls 3, gradually increase in height above sea level as the walls
approach the narrow
end. The height will be based on the tidal currents being funneled and the
height differential
expected as compared to the surrounding water outside the Tidal Energy Power
Plant. Storm
surges along with safety considerations etc. will have to be taken into
account when final
designs are approved.
The turbines 4, are designed to handle the enormous pressure and these
turbines can also
be stacked and be both below the normal outside high tide level and above the
outside high
tide level.
The bottom floor 5, of the Tidal Energy Power Plant can slope upward toward
the turbines if
it is deemed feasible.
Netting and/or pylons 6, will be installed to help prevent aquatic animals
from entering the
structure. Further barriers such as nets can surround the perimeter of the
whole structure.
A platform 7, where facilities for the production of hydrogen can be located
along with
buildings and offices for the maintenance of the plant etc. Below this
platform are the conduits
for the water to return to the surrounding water outside. Pipelines to the
shore and or
transmission lines to the shore can also be incorporated.
A dock for ships along with a helipad for helicopters 8, can be located here
or at any location
on the platform 7, deemed suitable.
This is where gates 9, can be located that can be closed to store water for
nominal power
generation after the tidal force has diminished.
This depicts an elongated pond-like area 10, where the water can be stored for
nominal
power generation when the gates 9, are closed. This area can be as large as
needed for this
purpose. It can also house more turbines 4, as compared to the amount in FIG.
1.
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Although the drawings and written descriptions provide a reasonable
explanation as to how
the Tidal Energy Power Plant would operate; additional embodiments such as
wind turbines on
top of the structure, or a possible way to harness ebbing tides etc., would
have to be examined
thoroughly to determine their feasibility. If any such embodiments are
determined to be
feasible, they may be incorporated into the final design.
