U.S. patent application number 12/188351 was filed with the patent office on 2009-09-10 for man made island with solar energy collection facilities.
This patent application is currently assigned to Centre Suisse d'Electronique et de Microtechnique SA. Invention is credited to Thomas Hinderling.
Application Number | 20090223508 12/188351 |
Document ID | / |
Family ID | 41052327 |
Filed Date | 2009-09-10 |
United States Patent
Application |
20090223508 |
Kind Code |
A1 |
Hinderling; Thomas |
September 10, 2009 |
Man Made Island With Solar Energy Collection Facilities
Abstract
A manmade island [10], adaptable for land-based or sea-based
operation holds solar energy collection facilities and is rotatable
to optimize the angular orientation thereof relative to the
position of the sun. More particularly, the man-made island [10]
uses a platform [12] that includes a large outer ring [14] that
floats on a fluid, and a flexible cover [16] attached to the ring
[14] to define an airtight volume [30] below the cover [16]. A
plurality of rows [19] of solar radiation collector modules are
located above the cover [16], and carry steam generating heat pipes
[21]. The rows [19] of modules are supported laterally above the
cover [16] by an upper support structure, either a space frame
[27], a plurality of cables [46] or a honeycomb [75]. A compressor
[32] creates an over-pressure within the enclosed volume [30] to
vertically support the cover [16] and the other components mounted
thereabove. This structure for supporting the rows [19] of the
solar radiation collector modules enables the man-made island [10]
to be constructed with a very large surface area, eventually up to
several kilometers in diameter, to better utilize the full
potential of the solar concentrators [22], thereby to produce
electricity at an economically viable cost. The man-made island
[10] includes a number of other structural features that enhance
the practical application of solar radiation collection
technology.
Inventors: |
Hinderling; Thomas;
(Neuchatel, CH) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER, 441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
Centre Suisse d'Electronique et de
Microtechnique SA
Neuchatel
CH
|
Family ID: |
41052327 |
Appl. No.: |
12/188351 |
Filed: |
August 8, 2008 |
Current U.S.
Class: |
126/628 |
Current CPC
Class: |
B63B 35/44 20130101;
Y02B 10/20 20130101; Y02B 10/22 20130101; F24S 30/422 20180501;
Y02E 10/47 20130101; F24S 20/70 20180501; B63B 2035/4453
20130101 |
Class at
Publication: |
126/628 |
International
Class: |
E04D 13/18 20060101
E04D013/18 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 5, 2008 |
US |
PCT/US2008/055925 |
Claims
1. A solar energy collection system comprising: a platform floating
above a body of fluid, the platform including an outer ring
structure and a flexible cover that sealingly encloses a top end of
the outer ring structure, thereby to define an enclosed volume
below the cover; a compressor for creating a suitable over-pressure
condition within the enclosed volume; a plurality of solar
radiation collector modules held above the cover; all upper
structure located above the cover and holding the solar radiation
collector modules; and the platform being rotatable about a center
horizontal axis thereof, thereby to enable the orientation of the
solar radiation collector modules to be variable and placed at a
desired orientation depending on the angular position of the
sun.
2. The solar energy collection system of claim 1 wherein the system
is land-based and further comprising: a lower ring-shaped trough
residing below the outer ring structure and adapted to hold a fluid
of suitable viscosity, thereby to floatably support the outer ring
structure on the fluid within the trough.
3. The solar energy collection system of claim 2 wherein the fluid
is water.
4. The solar energy collection system of claim 1 wherein the
suitable overpressure is at least 1/10 bar.
5. The solar energy collection system of claim 1 wherein the outer
ring structure is at least several meters tail.
6. The solar energy collection system of any of the prior claims
wherein the cover has at least one of the following
characteristics: a) UV resistant; and b) of foil composition.
7. The solar energy collection system of claim 1 and further
comprising: a drive mechanism adapted to driveably rotate the
platform about its center axis to a desired position, depending on
the position of the sun; and a computer operatively connected to
the drive mechanism and adapted to control the position thereof
according to a suitable algorithm.
8. The solar energy collection system of claim 1 and further
comprising, a plurality of strain gauges mounted on the upper
structure and operatively interconnected in a network, the strain
gauges adapted to sense the strain on the upper structure; mid a
controller operatively connected to the network and also to the
compressor, and adapted to dynamically adjust the over-pressure
condition within the enclosed volume so as to minimize the
mechanical load on the upper structure.
9. The solar energy collection system of claim 1 and further
comprising: an energy conversion system operatively connected to
the solar radiation collector modules.
10. The solar energy collection system of claim 9 wherein the
energy conversion system comprises an electrolysis generator for
producing hydrogen.
11. The solar energy collection system of claim 10 wherein the
electrolysis generator is located within the outer ring
structure.
12. The solar energy collection system of claim 1 wherein the
platform is sea-based, and further comprises: a plurality of
propulsion mechanisms located at selected positions around the
periphery of the outer ring structure, and operable to move the
platform to a desired location to optimize the operation of the
solar radiation collector modules.
13. The solar energy collection system of claim 1 and further
comprising: rainwater drainage channels formed in the cover to
facilitate rainwater runoff; and a water collection device
operatively connected to the rainwater drainage channels.
14. The solar energy collection system of claim 13 and further
comprising: a sea-water desalinization facility in cooperation with
the water collection device.
15. A method for collection solar energy comprising: floatably
supporting a platform, the platform being rotatable relative to a
center axis, the platform including an outer ring structure and a
flexible cover extending across and sealingly enclosing an upper
end of the outer ring structure, thereby to define an enclosed
volume below the cover, the platform holding an upper structure
that supports thereon a plurality of solar radiation collector
modules; and pressurizing the enclosed volume to a sufficient
degree of over-pressurization to maintain a desired floating effect
for the flexible cover and the solar radiation collector modules
located thereon.
16. The method of claim 15 wherein the outer ring structure of the
platform floatably supports on a fluid.
17. The method of claim 15 and further comprising: sensing a strain
condition associated with the upper structure; and dynamically
adjusting the over-pressurization of the enclosed volume in
response to the sensed strain condition.
18. The method of any of claim 15 and further comprising: driveably
rotating the platform about its center axis to maintain the solar
radiation collector in a desired, optimum orientation relative to
the position of the sun.
19. The solar energy collection system of claim 15 wherein the
platform is sea-based, and further comprising: propelling the
platform via controlled operation so as to steer the platform north
and south across the equator, as desired, and to maintain the
platform in a position that is oriented vertical to the sun.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a man-made island, either
land-based or sea-based, that is equipped with solar energy
collection facilities. More particularly, the present invention
relates to a large scale structure of this type which is capable of
producing electrical energy in a cost-effective manner via solar
thermal technology.
BACKGROUND OF THE INVENTION
[0002] It is generally accepted that the earth is fast approaching
an energy crisis of incalculable proportions. Some say that crisis
will occur around the year 2040.
[0003] It appears that solar power may be the only source that can
theoretically overcome the upcoming energy crisis without
disrupting energy costs. Geothermal or tidal energy is a distant
second possibility, but clearly at much higher costs.
[0004] Solar energy is principally suited to mitigating such a
future energy crisis. For instance, almost 10'000 GTEP (TEP=Tons
Equivalent Petrol) of solar radiation reaches the earth every year.
Yet, only up to 5 GTEP of usable solar power would be needed to
make a significant step toward energy sustainability for the
earth.
[0005] However, there have been practical limitations to
large-scale implementation of energy producing systems that rely on
the sun. For example, photovoltaic cells are capable of converting
solar energy i.e. sunlight) to usable energy, i.e. electricity. But
the overall efficiency of these devices is about 10-18%, depending
on the materials used. Also, higher efficiency generally requires
more expensive materials. Still further, the manufacture of
photovoltaic cells requires the use of highly toxic chemicals,
which present a significant and ever-expanding environmental
problem. Photovoltaic technology will be very important but is not
yet usable in large scale.
[0006] For these reasons, solar thermal technology, the other main
technology for converting solar energy to electricity, seems to be
the best solution for producing a sufficient number of GTEPs in the
foreseeable future, while remaining relatively inexpensive.
[0007] A specific solar thermal technology that is now widely being
used in pilot applications is the solar parabolic trough. A
parabolic trough, shaped like the bottom half of a large drainpipe,
reflects sunlight to a central receiver tube that runs above it.
Pressurized water or other fluids are heated in the tube and used
to generate steam, which can then drive turbo-generators to produce
electricity or to provide heat energy for industry.
[0008] In theory, parabolic troughs have had the potential for
efficient electricity production, because they can achieve
relatively high turbine inlet temperatures. However, in practice
the land requirements for this technology are significant.
Moreover, recent studies indicate that previously estimated
electricity costs, using this technology, may have been
over-optimistic. In short, the perceived promise on this technology
has not yet delivered tangible benefits, in a practical sense,
either due to inefficiencies or excessive costs, and also due to
the inherent limitations. More specifically, these trough
collectors require expensive and maintenance-intensive guidance
systems to dynamically adjust the angular positions of the panels
of the trough, dependent on the sun's position. This requires
expensive gear drives, and also large support structures that can
withstand significant load fluctuations and other structural
considerations. They are difficult to clean and susceptible to
wind.
SUMMARY AND OVERVIEW OF THE PREFERRED EMBODIMENTS
[0009] It is an object of the present invention to achieve
practical and tangible progress in harnessing solar energy, to
mitigate the known concerns associated with current sources of
electrical energy, including the possibility of a significant
energy crisis in the foreseeable future.
[0010] It is another object of this invention to facilitate the
large scale generation of electrical energy via the use of solar
radiation, and to do so at an economically viable cost.
[0011] The present invention achieves these objectives by placing
solar radiation collector modules on a large scale lightweight
man-made island or islands that are low-cost, up to several hundred
meters in diameter, and possibly even constructed with a diameter
of over one kilometer. The island could either operate at sea, on
large natural lakes, or on fluid where it would be based within a
recessed trough of concrete that would hold a fluid of appropriate
viscosity such as natural oil, or even water. The island floats.
The word lightweight refers to specific weight, that is platform
surface space/overall weight.
[0012] This island will be relatively tall in height, e.g., more
than 10 meters, and possibly even as tall as 30 meters to avoid or
at least minimize any negative effects of rough seas, etc. The land
version, however, can theoretically be built much lower, i.e. about
2 meters. Nonetheless, the land-based version could also benefit
from a certain height if it is deployed in a difficult environment,
such as a desert. In that case, a minimum height would help in
enabling the solar concentrator modules to be located well above
the desert surface, out of harm's way in the case of sand storms.
The greatest abrasive effect of sand storms occurs in the boundary
layer just above the ground. Generally, if the island is taller
than the typical height of this boundary layer, the solar
concentrators and other installations will be much less prone to
suffer defects as a consequence of sand storms. The island rotates
to track the position of the sun. The land-based version of this
island floats on liquid held within a large ring-shaped trough, via
a large outer ring structure sized to fit within the trough. The
sea-based version also uses the outer ring structure. The floating
outer ring facilitates rotation of the island to a desired
orientation, to optimize the position of the solar radiation
collectors located on the island. Instead of adjusting the
positions of the multiple modules of the solar collectors, the
collector modules are fixed in place, and adjustment of the
collector modules is achieved through rotation of the entire
island.
[0013] The island is essentially circular, although the outer ring
structure does not have to be exactly circular. For the land
version of the island the base of the outer ring structure must
have a bottom element that is close to circular in shape, to allow
the bottom element to rotate around within the concrete trough
described above. The outer ring could also be assembled from
segments of straight pipe sections that have a cross-section that
is round, square, oval or any other suitable shape. The outer ring
structure may use typical features that are common in ship design,
such as isolating the interior volumes within those pipe sections,
to protect against the possibility of sinking, if the outer ring
develops a leak. One preferred embodiment of the invention
contemplates the use of pipe sections that are typically used for
oil pipelines.
[0014] The outer ring structure could hold or support electrical
facilities such as all the equipment for actually producing
electrical energy in a Rankine cycle, by using the steam delivered
from the solar concentrator modules. This would generally be
state-of-the-art machinery such as steam turbines or Stirling
engines or any other type of machine suitable to use steam to drive
an electrical generator.
[0015] According to one preferred embodiment of this invention, a
man-made island with solar collection facilities includes a
floating platform, the platform primarily comprising a flexible
cover, or foil, which extends across an outer ring structure and is
sealed thereto. The top cover is an industrial-grade, long-life and
UV-resistant material that is either vulcanized and or clamped or
attached by any other suitable manner to the outer ring structure,
so that it is airtight. This creates an enclosed volume below the
cover. A compressor system is installed so as to be in fluid
communication with the enclosed volume and operable to create a
slight over-pressure under the cover. Current studies show that an
over-pressurization of about 0.005 bar should be sufficient, but in
some situations it could be substantially greater. Also, the
over-pressure is dynamically adjustable, as described below, to
achieve and maintain a desired floating effect and to position the
height of the cover, or membrane. It may be desirable to pressurize
the enclosed volume to the point of creating an upwardly directed
bulging effect, to facilitate rainwater runoff in a radial outward
direction. Also, the cover could include channels to facilitate
runoff in the desired direction. In fact, the runoff could be used
as part of a sea-water desalinization system. To achieve the
desired over-pressurization, a plurality of compressors, i.e.
pumps, may be used.
[0016] For the land-based system, a land wire facility operatively
connects the man-made island to the local grid. Where no
substantial electrical grid is available for correction, a hydrogen
production facility is connected. For the water-deployed version,
the man-made island has a sufficient number of propulsion devices
driven by electrical or other power distributed along the outer
ring structure. These propulsion devices may move the island to a
desired location, and also turn the island to a desired orientation
relative to the sun.
[0017] The land-based version of the man-made island of this
invention has centering mechanisms, namely wheels, for centering
the island on its axis of rotation within the trough. To turn the
island, this structure uses driveable wheels that roll on the
outside of the concrete ring. Because the man-made island is
floatably supported, the power actually needed to rotate the island
is minimal. Relatively small motors distributed around the outer
structure will be suitable for turning the island by approximately
180 degrees in one day due to the symmetrical layout of the
collectors, although it would also be possible to turn the island
360 degrees in one day.
[0018] To reduce the total weight of the island, and to reduce
susceptibility to flexing due to wind, the solar radiation
collector modules supported on the platform have a flow-through
lightweight design which allows air to actually flow through the
concentrator panels. Such collectors can be assembled from plain
industrially manufactured, mirrored band steel or aluminum. This
type of design substantially reduces costs and weight compared to
typical parabolic trough designs. Also, this design can be easily
assembled in countries close to the equator, where difficult
manufacturing processes, e.g., the bending of large-scale aluminum
mirror elements, may not be feasible.
[0019] The enclosed volume of this man-made island is bounded by
the outer ring structure, the cover, and the water surface (for the
sea-based version), or the land surface (for the land-based
version). For the land version, the sealing effect for the enclosed
volume is achieved in part by the concrete trough. One particular
advantage with the land version is that the earth surface
underneath the cover can remain untreated. Also, this surface could
hold some of the technical installations used to operate the
island. Thus, those installations would not necessarily have to be
supported by the outer ring structure, as would be the case for the
man-made island floating at sea. If an installation were actually
located under the platform, for the land version, overlying
sections of the cover could be made of transparent material. This
would provide for some ambient sunlight to reach facilities below,
in which the operating team is working.
[0020] An upper structure resides above the cover, and supports the
solar radiation collector modules. According to a first preferred
embodiment, this upper structure is a space frame. According to a
second preferred embodiment, a pre-tensioned cable system spans the
cover, and the outer ring structure holds the mounts for these
cables. Still further, a honeycomb structure could be used as this
upper structure. The air cushion under the cover is maintained at a
pressure that actually supports the upper structure. For this
purpose the upper structure, or even the modules or the cover,
holds a plurality of sensors, such as strain gauges, that are
interconnected in a network that is operatively connected to a
computer, which is in turn connected to the compressor system. The
sensors measure a desired measurable condition related to the
cover, such as the strain on the upper structure, at difference
places around the cover. The computer uses an appropriate algorithm
and corresponding software to control the compressor system to
dynamically adjust the air pressure under the cover, to minimize
the strain on the upper structure, or to address the sensed
condition in an appropriate manner. It is to be understood that any
one of a number of other force measuring devices could be used to
dynamically sense and analyze the mechanical load on the cover, the
upper structure, or the modules, and to initiate an appropriate
change in over-pressurization.
[0021] This man-made island is particularly lightweight because the
upper structure holding the solar concentrator modules will barely
have to be able to support its own weight. Any excess forces
induced by wind or any other atmospheric or untoward effects can be
compensated by the overpressure cushion under the flexible cover,
particularly via appropriate sensors and dynamic control of the
compressor system.
[0022] According to another aspect of the invention, the outer ring
structure has additional support frames on the outside thereof, to
hold photovoltaic (PC) elements. Electrical power generated by
those PV elements and their battery storage and DC/AC converter
facilities could be used to power the positioning systems of the
island and also the operating room systems, such as the drive
system, and the compressor system.
[0023] According to still another aspect of the invention, the
sea-based version contains propulsion equipment mounted at multiple
points around the outer ring structure, to move the island north
and south across the equator in parallel with the seasons. This
enables the island to maintain a vertical position under the sun's
daily path. It has been shown that solar power output could be
increased by up to 15 percent per year if a solar energy production
facility is actually able to follow the sun's path in the manner
suggested here. The positioning system of such an island could
include a GPS system with appropriate computing equipment including
the algorithms and associated software establishing latitude and
longitude based on the law of Cook (see
http://fred.elie.free.fr/cadrans_solaires.htm. The same positioning
system would also maintain the island's angular position during the
day when it essentially turns through about 180 degrees to follow
the sun from rise in the east to sunset in the west.
[0024] A brief calculation of the potential output of this man-made
island, with a diameter of 500 meters, is shown below. Such an
island would have a surface area inside the outer ring structure of
about 195,000 square meters. Solar radiation in the tropics is
approximately 1 kW per square meter. Assuming a somewhat
conservative overall transformation efficiency (concentrators,
Rankine cycle etc.) of between 10 and 20 percent, the peak output
of such an Island can be estimated to be over 30 MW. This assumes
that the island operates at peak power during about 8 hours per
day. For purposes of this calculation, additional power generated
at less than peak output during the morning and evening hours has
been omitted. This would result in an output of approximately 240
MWh per day or about 85000 MWh per year, assuming that 15 days per
year are reserved for maintenance operations. Thus, one such island
could produce an amount of electrical power in one year that is
approximately worth $12.75 million at an average sales price of
$0.15/kWh. According to a more conservative assessment, the mean
power over a period of 24 hours would be 7.4 Mw. Using the same
general assumptions as stated above, this would result in an output
of approximately 177 MWh per day, or about 61,850 MWh per year,
worth approximately $9.28 million at the same average sales price
listed above.
[0025] The economics behind this man-made island become more
attractive as the size of the island increases. Also, the increase
in size further increases stability for the water-deployed version,
particularly in adverse weather. Thus, this inventive man-made
solar island represents a major contribution toward sustainable
energy production that will so desperately be needed in the near
future.
[0026] The over-pressurization of the enclosed volume below the
cover plays a significant role in supporting the solar radiation
collector modules. More particularly, to generate electricity from
solar radiation at an economically viable cost, the surface area
needed is extremely large. Although commercially available solar
collectors continue to improve in efficiency, the surface area
requirements, i.e. the surface area occupied by the collectors, are
still immense. The need for large surface area creates other
practical considerations, namely how to sufficiently support the
collectors on a load bearing structure that is also reorientatable
relative to the position of the sun. With this invention, the
answer is threefold. First, the large outer ring floatably supports
the periphery of the island. Second, the over-pressurized volume
below the cover helps to balance the load on the platform. Third,
the use of an appropriate upper support structure, i.e. a
lightweight space frame, or alternatively, a tensioned cable
system, or a honeycomb structure, further assures adequate lateral
mechanical support for the solar collector modules mounted on
top.
[0027] A water supply pipe (inbound) and a steam pipe (outbound)
connect to the solar radiation collector modules via a rotary joint
located at the center of the island. This joint must be able to
accommodate the rotation of the island. This can be done by a
coaxial configuration, a coaxial swiveling joint or even by a
suitable length of a flexible hose.
[0028] Once these pipes have reached the top of the platform, they
are routed along the rows of the solar radiation collector modules,
to generate usable steam via heat pipes onto which the sunlight is
concentrated. Because the length of the various pipes extending
from the center of the island to all of the various collector
modules will differ, pressure regulator valves are used to moderate
and control any undesired pressure differences.
[0029] Along the modules, various layouts or arrangements of the
heat pipe layout are possible. One such arrangement involves
running the outbound water lines along the tops of the heat pipes
of the solar collector modules, to preheat the water flowing in
these upper pipes as a result of their proximity to the respective
heat pipes located therebelow.
[0030] The present invention also contemplates the capability of
cleaning and servicing the solar collector modules via a driveable
cart, or other device, that moves along a rail or track that
extends alongside the rows of collectors. This device could be a
robot that directs pressurized fluid, most likely air, at the
surfaces of the modules. The track could be a dual rail track which
supports a wheeled cart, or even a monorail-type track. The wheeled
cat configuration enables travel along the rails to any desired
position on the platform to provide access for any needed
maintenance.
[0031] These and other features of the invention will be more
readily understood in view of the following detailed description
and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a perspective view of the man-made island
constructed according to a first preferred embodiment of the
invention.
[0033] FIG. 1A is a horizontal sectional view which schematically
shows a sea-bound version of the man-made island, according to one
aspect of the invention.
[0034] FIG. 2 is a horizontal sectional view which schematically
shows a land-based version of the man-made island, according to
another aspect of the invention.
[0035] FIG. 3 is a plan view, in schematic form, which shows a
land-based version of the man-made island of this invention.
[0036] FIG. 4A is a horizontal sectional view which schematically
shows the outer ring structure and the trough of a land-based
man-made island according to one preferred embodiment of the
invention.
[0037] FIG. 4B is a horizontal section view, similar to FIG. 4A,
which schematically shows yet another variation of the outer ring
structure and the trough, for the land-based version of the
man-made island of this invention.
[0038] FIG. 5 is a perspective view of a drive wheel unit, shown
connected to the outer ring structure, according to one preferred
embodiment of the drive mechanism of this invention.
[0039] FIG. 6 is a perspective view, star to FIG. 4, of a centering
wheel unit, shown connected to the outer ring structure, according
to one preferred embodiment of the centering mechanism of this
invention.
[0040] FIG. 7A is a perspective view of a pod supporting a portion
of a lightweight space frame on the cover of the platform, in
accordance with a first preferred embodiment of the upper structure
of this invention.
[0041] FIG. 7B is a horizontal view which schematically shows the
pod and other structures shown in FIG. 7A.
[0042] FIG. 8 is a perspective view which schematically shows the
bottom of a pod of the type shown in FIGS. 7A and 7B.
[0043] FIG. 9 is a perspective view which schematically shows a
computer-model generated simulation of the depressions that could
occur on the cover of the man-made island of this invention.
[0044] FIG. 10 is a horizontal view that schematically shows a
second preferred embodiment for the upper structure of this
invention, namely a cable system that cooperates with a plurality
of pontoons, which in turn hold support boards onto which
Fresnel-type solar concentrators are mounted.
[0045] FIG. 10A is a perspective view showing an alternative
pontoon structure.
[0046] FIG. 11 is a horizontal view which schematically shows a
third preferred embodiment for the upper structure of this
invention, a honeycomb structure onto which a Fresnel-type
collector is mounted.
[0047] FIGS. 12A and 12B are perspective views which show two
alternative structures for routing fluid, i.e. water and/or steam,
to and from the island 10 via a rotary joint located at the hub
11.
[0048] FIG. 13A is a longitudinal view along one of the rows of
Fresnel collectors, showing a rail supported cart which facilitates
service and maintenance.
[0049] FIG. 13B is a cross-sectional view along lines 13B-13B of
FIG. 13A.
[0050] FIG. 14 is a perspective view which shows another aspect of
the cart shown in FIG. 13A.
DETAILED DESCRIPTION OF THE DRAWINGS
[0051] The present application claims the priority benefit of U.S.
Provisional Application Ser. No. 60/892,956 filed Mar. 5, 2007,
entitled "Solar Island"; and PCT Application No. US2008/55925,
filed Mar. 5, 2008, with the same title. These applications are
expressly incorporated by reference herein, in their
entireties.
[0052] FIG. 1 shows a man-made island 10 constructed in accordance
with one preferred embodiment of the invention. The island 10
generally comprises a horizontal platform 12, which in turn
includes an outer support ring structure 14 that is spanned by a
flexible cover 16. The cover 16 may be of any suitable flexible
material that can be sealed along its opposing longitudinal edges,
such as for instance by gluing, heat welding, or vulcanizing the
adjacently located edges. In an initial prototype of the invention,
for the cover 16 applicants are using a industrial foil known as
SIKA Sarnafil TS 77-20. The island 10 includes a central hub 18
which will be described later in more detail.
[0053] The platform 12 supports a plurality of solar radiation
collector modules arranged end to end in a plurality of parallel
rows 19. Any given row 19 of modules includes a plurality of wire
supported uprights 20, which in turn hold a horizontally oriented
heat pipe 21. Each of the rows 19 includes a plurality of lower,
parallel mounted solar concentrators, or reflector panels 22. Each
of the concentrators 22 is fixed at a desired angle, so that all of
the reflectors 22 reflect, or direct, sunlight upwardly toward the
heat pipe 21. The platform 12 rotates to keep the rows 19 oriented
towards the sun.
[0054] A water supply pipe and a steam pipe are routed to the
central hub 18, and connect to two conduits 24 that extend in
opposite directions. The conduits 24 connect to sub branches 24a
that extend generally along the center of the island 10, so that in
each row 19, the supply water can flow out and back along the
respective heat pipe 21.
[0055] FIG. 1 also shows a plurality of pods 25 distributed across
the upper surface of the cover 16, in a grid pattern designated
generally by reference number 26. Although not shown in particular
detail in FIG. 1, the pods 25 support a lightweight space frame 27,
which generally occupies the spaces designated by the gridlines 26
in FIG. 1. The space frame 27 in turn supports the rows 19 of solar
radiation collector modules. The space frame 27 is one form of the
upper structure used to support the rows 19 of modules.
[0056] FIG. 1A shows a sea borne version 10a of the island, bounded
by a sea-borne outer ring 14a. Propulsion equipment 14b, i.e.,
suitably mounted outboard motors, are located at a selected number
of points on the periphery of the sea borne ring 14a.
[0057] As described above, land-based or sea-based, this inventor
contemplates a man-made island as a floating structure. FIG. 2
shows more details of the structural components of one preferred
embodiment of the land-borne version of this man-made island 10.
More particularly, FIG. 2 shows the overall structure, and the
manner in which the island 10 is floatably supported by the outer
ring 14. Preferably, the ring 14 is made of connectable,
prefabricated segments of steel, concrete, plastic, aluminum, or
any other suitable material. If the segments of the ring 14 are
made of steel, they are preferably welded together. Particularly
for a sea-based version of the island 10, the segments have
internal support structures. These internal support structures
isolate adjacently located segments of the ring 14, so as to
isolate any leaks that might occur. In one prototype construction
of the land-based version of this island 10, the platform 12 is
about 85 meters in diameter, the segments have a diameter of about
two meters, and a length of about 7.5 meters. Preferably, the
sections of the ring 14 are placed aid inter connected while in the
trench 28, and preferably supported on a temporary structure which
can then be removed after the trench 28 is filled with water 29.
The trench 28 must be able to support the weight of the ring 14.
For the prototype, applicants estimate that the ring 14 will have a
total weight of about 100 tons (100,000 kg), which corresponds to a
weight of about 380 kg per square meter.
[0058] FIG. 2 shows the outer ring 14 floatably located within a
trench or trough 28. As shown in FIG. 2, the trench has an inside
wall 28a, a bottom wall 28b, and an outer wall 28c. The trench 28
is preferably made of concrete. The thickness of each of the walls
28a, 28b, and 28c is determined according to local geological
surveys and any applicable building code. The trench 28 includes a
fluid of suitable viscosity, and particularly a liquid such as
water 29, so as to float the support ring 14.
[0059] FIG. 2 also shows the enclosed volume 30 located below the
cover 16, and further defined, or bounded by the ring 14, the water
29 in the trough 28, and the ground 31 or floor surface located in
the center of the island 10. Preferably, the surface 31 is even
with the top of the inside wall 28a. This may be done by
sand-filling, and the sand then covered by PVC foil of 2 mm
thickness, preferably a flexible polyolefin based foil reinforced
with polyester thread and/or a fleece made of glassfibre. A
compressor system 32, preferably a plurality of compressors, or
pumps, is located so as to be in fluid communication with the
enclosed volume 30. In FIG. 2, the pump 32 is shown below the floor
31 in the middle of the island 10. Nonetheless, it could also be
centrally located within an operations room or facility for
operating the island 10, or even placed on the ring 14. The pump 32
pumps air into the enclosed volume 30, as shown by directional
shows 34, to maintain a suitable over-pressurization condition
beneath the cover 16 and within volume 30. Applicants currently
expect that the actual amount of over-pressure within the enclosed
volume 30 will be about 0.005 bar, although that value may vary
somewhat depending upon the dynamic conditions, and in some
situations it could be substantially greater. FIG. 2 also shows an
upwardly extending outer rim structure 14a, which extends upwardly
from each of the segments of the ring 14 to create an outer top
surface 14b around the top of the ring 14.
[0060] FIG. 3 shows one example of the land-based version of this
man-made island 10, including a radially oriented subsurface tunnel
35 that extends outwardly from the center hub 18 of the structure,
beyond the outer wall 28c of the trench 28 to an energy facility
36, which may be a turbine generator or other facility for storing
or using the solar generated steam produced by the island 10.
Preferably, the tunnel 35 carries the water pipes which connect to
the conduits 24, and also any electrical connectors. The tunnel 35
floor slopes downward from the center of the island 10, so as to
extend below the bottom of the trench 28 and also to prevent any
water or other liquid from flowing to the center of the island 10.
A pond 37 is located nearby to supply water to the trench 28, as
needed. It preferably connects to trench 28 from below, to
facilitate quick draining of the trench 28.
[0061] FIG. 3 also shows another view of the rows 19 of modules.
Generally, for each module the concentrators 22 are about 8 meters
in length.
[0062] FIG. 2 and also FIG. 4A show details of a centering
mechanism 38 that centers the island 10 on its central axis. More
specifically, the centering mechanism 38 resides radially beyond
the ring 14 and within the inside surface of the outer wall 28c of
trench 28. This centering mechanism 38 comprises a bracket 39
mounted to the ring 14, which supports a rotatable wheel 40 that
resides in contact with the outer wall 28c. It is important that
the inner surface of the outer wall 28c be constructed so as to be
perfectly round, or with a very low tolerance. This requirement is
necessary because angular adjustment of the island 10 is achieved
via these wheels 40. The invention also contemplates an alternative
mounting option, that of mounting the brackets 39 on the outer wall
28c so that the wheels 40 contact the ring 14.
[0063] Although the number of wheels 40 may vary, applicants expect
that twelve such wheels 40 will be needed around the circumference
of the ring 14, with the wheels spaced every 30 degrees.
Nonetheless, additional wheels could be used to more equally
distribute the load between the outer wall 28c and the ring 14. The
wheels 40 can be standard automotive wheels. Also, some of the
wheels 40, preferably four, serve the additional purpose of
rotatable driving the ring 14 about its axis to a desired position,
to optimize the performance of the reflectors 22. Thus, some of the
wheels 40 are part of the centering mechanism and the driving
mechanism. FIG. 4A also shows a motor housing 50, which indicates
that the wheel 40 shown is one of the four dual purpose wheels
40.
[0064] Those skilled in the art will appreciate that at any given
time the force between the wheels 40 and the wall 28c will act on
only one side of the ring 14, depending upon the direction of the
wind. Thus, only about half of the centering wheels 40 will be used
to transmit angular force to the ring relative to the outer wall
28c. Nonetheless, the outer wall 28c and its foundation must be
dimensioned and reinforced so as to carry this load. If there is no
wind at all, or very low wind, then all of the wheels 40 will
contact the outer wall 28c and carry the rotational load, although
the load will be more evenly distributed about the entire
circumference of the ring 14.
[0065] FIGS. 4A and 4B show the outer ring structure 14, along with
some of the structural details of the island 10. Due to the larger
size of FIG. 4A (compared to FIG. 2), FIG. 4A shows more clearly
all outer bracket 42, preferably a steel ring torus with a U-shape,
turned on its side, which secures or clamps the outer peripheral
edge of the cover 16. FIG. 4A also shows some aspects of one
preferred structure used to support the rows 19 of solar collector
modules. More particularly, FIG. 4A shows details of a tensioned
cable system which coacts with the pod 25. It is expected that the
cable 46 will need to accommodate a tension force in the range of
about 10-25 KN. More particularly, a fed mounting support 44 holds
the outer end of a tightened cable 46 which spans across the island
10 above the cover 16, in a manner which enables the pods 25 to
essentially hang from, or be suspended between, the cable 46 above
mad the cover 16 below. Preferably, the pods 25 are adapted to
accommodate the cable 46 of such a cable system and also the space
flame components, to enhance versatility in constructing the island
10 and in supporting the solar collector modules.
[0066] FIG. 4B is similar to FIG. 4A, except FIG. 4B shows another
variation of the invention wherein the ring 214 stores steam 114
generated by the collector modules, and the ring 214 is encased
within a square-shaped (in cross section) outer insulation section
215. FIG. 4B also shows an outwardly extending skirt 228d that
extends from the ring 214 to the outer wall 228c of the trench 228.
This skirt 228d is usable with the other variations of the
invention. The skirt 228d helps to prevent evaporation of fluid
from the trough 228, and may also aid in preventing dust or other
debris from falling therein.
[0067] FIG. 5 more clearly shows one of the centering wheels 40
that is also used to rotatably drive the island 10. This is
achieved by mounting a drive mechanism, i.e. a motor 50a, to the
same structure which supports a centering wheel, as shown in FIG.
6.
[0068] In either case, the wheel 40 has a bracket 39 mounted to the
ring 14. The bracket 39 includes a horizontally oriented hinge axis
39a, and a spring 41 that acts as a shock absorber between the
hingedly connected sections of the bracket 39 (hingedly connected
with respect to the axis 39a). FIG. 4A shows a motor housing 50,
which covers the motor 50a that is shown in FIG. 5. Preferably, the
drive mechanism includes a speed reducer 52 and an adapter 53
mounted to the bracket 39 with the wheel 40. Still further, as
shown in FIG. 3, the motor housing 50 operatively connects to a
computer controller 70 via an electrical connection, to rotatably
control the angular position of the island 10. This electrical
connection could be wireless, if desired, or via any other suitably
convenient electrical connector.
[0069] FIG. 7A shows an enlarged view of one portion of this
man-made island 10, and particularly a portion where a space frame
27 mounts to one of the pods 25. FIG. 7A particularly shows that
the space frame 27 preferably uses an I-beam construction. FIG. 7A
also shows that a top 25a of the pod 25 includes upwardly directed
channel brackets 25b for securely holding the lower ends of the
space frame 27. These brackets 25b may be part of a top piece 25a
of the pod 25, in the form of a plate, to which the brackets 25b
are connected by any sufficient securement mechanism. FIG. 7A also
shows the concentrators 22 supported on a lattice or pallet-like
structure 23, which also preferably uses an I-beam
construction.
[0070] In addition to the space frame 27, or as an alternative
thereto, the cable system can be used for supporting the solar
collector modules. FIGS. 7A and 7B show the cable 46 in phantom, to
illustrate that it is an additional, or an alternative structure
for providing support. Also, as shown in FIG. 7B, the pod 25
includes upwardly extending hangers 25c which connect to the cable
46. Still further, FIG. 7B shows a sensor 60, which may be a strain
gauge, mounted in position to sense the strain on the space frame
27. As mentioned previously, a plurality of such sensors 60 are
distributed throughout the platform 12, and are operatively
connected in a network (not shown) to convey to the computer
controller 70 (FIG. 3) the sensed conditions. The sensors 60 may be
adapted to sense any one of a number of different measurable
conditions. Preferably, the controller 70 also causes the
compressor system 32 to respond appropriately to the sensed
conditions, by dynamically adjusting the amount of over
pressurization.
[0071] FIG. 8 shows a bottom profiled surface 25d of pod 25. FIG. 9
is a computer simulated view of the cover 16, with three noticeable
dimples, or depressions, as a result of the load supported
thereabove. These dimples are designated via reference numerals
16a, 16b, and 16c. They show the need for dynamic
over-pressurization and strain sensing to achieve a horizontal
position of the solar collector modules mounted thereabove. For
this embodiment of the invention, or any embodiment involving
spaced pods located on the cover, it would be preferable to include
drainage valves within the cover, to avoid rainwater accumulation
around the pods. Such valves need to remove water from the top of
the cover, while preventing any pressure leakage from under the
cover.
[0072] FIG. 10 is similar to FIGS. 4A and 4B, but shows more
details of the cable and pontoon structure used to support the rows
19 of solar collector modules. In this particular embodiment of the
invention, the cable 46 spans across the top of the cover 16,
transversely across a plurality of pontoons 72 which are arranged
in parallel rows on the cover 16. The pontoons 72 can be made of
plastic or any other suitable light weight material. Applicants
contemplate using pontoons of the type industrially manufactured
and distributed by e.g. Robin Kunstoffprodukte, of Teterow, Germany
and Tecutus K G (GmbH and Co.), also of Teterow, Germany.
Preferably, the cable 46 engages a plurality of braces, or boards
74, supported on top of the pontoons 72 (or rows of pontoons). The
boards 74 support the lattice 23 which holds the solar
concentrators 22. FIG. 10 shows depressions formed in cover 16
alongside the pontoons 72. These parallel depressions facilitate
the runoff of rainwater, and also eliminate a centrally located
bulge that could result from the over-pressurization. Surface
runoff may be more controllable because it will generally flow to
these known depressions.
[0073] FIG. 10A shows another version of the pontoon, designated by
reference numeral 72a. This pontoon 72a has a formed, preferably
molded, top surface structure designed to facilitate holding of the
upper structure and/or other structure which supports the
modules.
[0074] FIG. 11 shows a side view of yet another embodiment of the
upper structure used to support the solar radiation collectors.
More particularly, FIG. 11 shows a honeycomb-type structure 75
residing between the cover 16 and the solar collectors 22c and also
supported by cable 46.
[0075] FIGS. 12A and 12B show variations on the rotary joint for
use at the center hub 18 of the island 10. More particularly, FIG.
12A shows an inlet pipe and an outlet pipe, designated 80a and 80b
respectively, both of which include a respective sleeve 81a and
81b, which permits some relative rotation between the upper and
lower sections thereof; at least in the range of about 240 to 260
degrees. FIG. 12B shows a coaxial version 82 of the rotary joint.
More particularly, water inlet 84 supplies water to an outer
annularly shaped flow passage within outer pipe 85, for water
flowing toward the solar collector modules. After the water has
been heated and steam has been created, it returns via central heat
pipe 86 (which is rotatable with respect to outer pipe 85 and to
the inlet 84). The steam generated via the solar collectors
eventually flows toward the bottom of the rotary joint 82 and exits
the joint via a steam outlet 88. Those skilled in the art will
appreciate that one or more pumps (not shown) may be used to cause
the water, i.e., the water to be heated, to flow to the island and
to the solar collector modules. Similarly, those skilled in the art
will also appreciate that one or more pumps (also not shown) may be
useful for assisting the outbound flow of steam from the island. To
some extent, the bleed for these additional components will depend
on the location and the type of energy generating device that is
operatively connected to the output line from the island.
[0076] FIGS. 13A and 13B show two additional features of the
invention. More particularly, FIG. 13A shows a wheel supported cart
90 which rolls along a pair of spaced rails 92 arranged parallel
with the rows 19 of the solar collector modules. This facilitates
maintenance of the collectors, and does so in a manner that does
not interfere with the solar collection structure.
[0077] FIG. 13B shows one embodiment for incorporating a preheating
feature into this invention. More particularly, FIG. 13B shows the
uprights 20 of cone of the rows 19 of solar collector modules, and
the heat pipe 21 configured as a coaxial pipe structure 94 that
spans between the uprights 20. More particularly, the pipe
structure 94 is a coaxial pipe with an outer annular channel 94a
and a centrally located inner channel 94b. With the panels 22 of
the solar collector modules concentrating and directing the
sunlight upwardly, water flowing outbound (to the left in FIG. 13B)
via central channel 94b is preheated by the heat emanating from
steam flowing in the outer channel 94a (which is flowing to the
right in FIG. 13B). The outer channel 94a receives the greatest
concentration of redirected radiation from the sunlight. Thus, the
heated steam within channel 94a also causes heat to emanate
radially inwardly to preheat the fluid flowing in the inner channel
94b. This same principle could be used with an upper outbound
channel 94a and a lower return (steam generating) channel 94b, if
the coaxial version of this piping structure proves too cumbersome
or too expensive to manufacture or install.
[0078] FIG. 14 shows the capability for the cart 90 to move
laterally along, or transversely to one of the rows 19 of solar
collectors, at the end of the row 19, as shown by directional arrow
97, along a transversely directed track. This enables the cart 90
to service the entire surface area of the cover 16 occupied by the
rows 19 solar collector modules. As shown in FIG. 3A, adjacent row
19 access could also be obtained by adding an outer half circular
track 94a to connect adjacently located rows. These connector tanks
can be removable, for temporary use, to accommodate multiple rows
19. The type of structure can be used for regular servicing of the
island 10, for example, for cleaning the panels 22 of the solar
collector modules.
[0079] One embodiment of the invention contemplates that the outer
ring structure, in the case of the water-deployed man-made island
10a (shown in FIG. 1A), would contain a hydrogen production
facility in a hermetically sealed pipe section attached under the
outer ring structure 14a. Such a hydrogen production facility could
be completely submerged, and run in a way that the electrolysis
generator could operate in an evacuated or an inert gas
environment, thereby to substantially reduce any potential accident
risks. It is also envisaged to use two concentric pipe sections in
the construction of such a hydrogen production facility--in other
words the electrolysis generator would then be housed in a
double-walled structure.
[0080] Hydrogen production and distribution facilities are
generally not considered to be dangerous; they are not
systematically prone to risks of uncontrolled combustion. However,
as
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SK%20ASSESSMENTS%20OF%20H2-REFULLOMG%20STATION_Onsite_%20CONCEPTS.pdf
shows, these facilities require frequent maintenance and ongoing
surveillance in order to effectively control such risks. An
evacuated environment or an environment filled with inert gas would
substantially reduce those risks, as hydrogen and oxygen gas
sensors would immediately warn about the risk of a leak developing.
For regular maintenance every few months, such a hydrogen
production facility could be shut off and outside air pumped in
before the maintenance crews enter the scene.
[0081] For the land-based version of the man-made island, a
hydrogen generation facility would be constructed at a sufficient
distance from the solar island 10 to prevent any potential
hazardous exposure.
[0082] While this specification describes a number of preferred
embodiments and other variations of the invention, those skilled in
the art will appreciate that the particular structures shown and
described are susceptible to a reasonable degree of modification,
and hence, the invention is not limited in scope to the specific
details shown and described. Application wishes only to be limited
by the broadest reasonable interpretation of the following
claims.
* * * * *
References