U.S. patent application number 11/361771 was filed with the patent office on 2007-08-30 for method of supporting a solar energy collection unit.
This patent application is currently assigned to Arizona Public Service Company. Invention is credited to David P. Haberman, Raymond S. Hobbs.
Application Number | 20070199560 11/361771 |
Document ID | / |
Family ID | 38442841 |
Filed Date | 2007-08-30 |
United States Patent
Application |
20070199560 |
Kind Code |
A1 |
Hobbs; Raymond S. ; et
al. |
August 30, 2007 |
Method of supporting a solar energy collection unit
Abstract
A method (92) of supporting a solar energy collection unit (22,
54, 76) of a solar energy system (20, 52, 78) calls for
redistributing (96) earth at a worksite (26) to form an elevated
earthen structure (24) having a sun facing surface (28), compacting
(102) the earthen structure (24), and arranging (106) the solar
energy collection unit (22, 54, 76) upon the sun facing surface
(28) of the earthen structure (24). The earthen structure (24) may
include internal strengthening material (32) detached from the
energy collection unit (22, 54, 76) and the earthen structure (24)
may be encased in a binder material (34) for additional stability.
Channels (48, 50) may be provided proximate the earthen structure
(24) for fluid supply and release functions.
Inventors: |
Hobbs; Raymond S.;
(Avondale, AZ) ; Haberman; David P.; (Boca Raton,
FL) |
Correspondence
Address: |
Meschkow & Gresham, P.L.C.
Suite 409
5727 N. 7th Street
Phoenix
AZ
85014
US
|
Assignee: |
Arizona Public Service
Company
Phoenix
AZ
|
Family ID: |
38442841 |
Appl. No.: |
11/361771 |
Filed: |
February 24, 2006 |
Current U.S.
Class: |
126/600 |
Current CPC
Class: |
Y02E 10/44 20130101;
Y02E 10/47 20130101; F24S 10/742 20180501; F24S 2025/014 20180501;
F24S 2025/02 20180501; F24S 25/10 20180501; F24S 80/30
20180501 |
Class at
Publication: |
126/600 |
International
Class: |
F24J 2/38 20060101
F24J002/38 |
Claims
1. A method of supporting a solar energy collection unit of a solar
energy system comprising: redistributing earth at a worksite to
form an elevated earthen structure having a sun facing surface;
compacting said earthen structure; and arranging said solar energy
collection unit upon said sun facing surface of said earthen
structure.
2. A method as claimed in claim 1 further comprising forming said
sun facing surface to have a first surface area at least as great
as a second surface area of said solar energy collection unit.
3. A method as claimed in claim 1 further comprising conforming
said sun facing surface of said earthen structure to a shape of
said solar energy collection unit.
4. A method as claimed in claim 1 further comprising aligning said
earthen structure to provide shade for a portion of said solar
energy system.
5. A method as claimed in claim 1 further comprising utilizing said
earthen structure for thermal management of said solar energy
collection unit.
6. A method as claimed in claim 1 further comprising orienting said
sun facing surface at an elevation angle from horizontal of greater
than ten degrees and less than ninety degrees.
7. A method as claimed in claim 1 wherein said solar energy
collection unit comprises enclosed members, and said arranging
operation comprises aligning a longitudinal axis each of said
enclosed members with a slope of said sun facing surface.
8. A method as claimed in claim 1 wherein said worksite includes
non-flat terrain, said energy collection unit is one of a plurality
of energy collection units of said solar energy system, and said
redistributing operation comprises: excavating said non-flat
terrain to create terraces; and forming a plurality of earthen
structures on said terraces for arranging said plurality of energy
collection units thereupon.
9. A method as claimed in claim 1 further comprising encasing said
earthen structure in a binder material.
10. A method as claimed in claim 9 wherein said binder material
comprises adobe.
11. A method as claimed in claim 1 further comprising incorporating
a non-earthen strengthening material internal to said earthen
structure.
12. A method as claimed in claim 11 wherein said non-earthen
strengthening material is detached from said solar energy
collection unit.
13. A method as claimed in claim 1 further comprising: providing a
channel proximate said earthen structure; directing a fluid through
said channel; and supplying a fluid inlet of said solar energy
collection unit with said fluid from said channel.
14. A method as claimed in claim 13 wherein said providing
operation comprises excavating said earth to form said channel as
an open channel.
15. A method as claimed in claim 13 wherein said channel is an
enclosed member, and said providing operation comprises installing
said enclosed member proximate said earthen structure.
16. A method as claimed in claim 1 further comprising: providing a
channel proximate said earthen structure; supplying said channel
with a fluid from a fluid outlet of said solar energy collection
unit; and directing said fluid through said channel.
17. A method as claimed in claim 16 wherein said providing
operation comprises excavating said earth to form said channel as
an open channel.
18. A method as claimed in claim 16 wherein said channel is an
enclosed member, and said providing operation comprises installing
said enclosed member proximate said earthen structure.
19. A method as claimed in claim 1 wherein said solar energy
collection unit is a photosynthetic bioreactor, said earthen
structure supporting said photosynthetic bioreactor.
20. A method as claimed in claim 19 wherein said solar energy
system includes a plurality of photosynthetic bioreactors, and said
redistributing operation comprises excavating said earth at said
worksite to form a plurality of elevated earthen structures for
supporting said plurality of photosynthetic bioreactors.
21. A method as claimed in claim 1 wherein said worksite is at
least one hundred acres, and said method comprises utilizing
substantially an entirety of said at least one hundred acres to
form a plurality of elevated earthen structures for supporting a
plurality of solar energy collection units.
22. A method of supporting a solar energy collection unit of a
solar energy system comprising: redistributing earth at a worksite
to form an elevated earthen structure having a sun facing surface;
forming said sun facing surface to have a first surface area at
least as great as a second surface area of said solar energy
collection unit; orienting said sun facing surface at an elevation
angle from horizontal of greater than ten degrees and less than
ninety degrees; compacting said earthen structure; and arranging
said solar energy collection unit upon said sun facing surface of
said earthen structure.
23. A method as claimed in claim 22 further comprising aligning
said earthen structure to provide shade for a portion of said solar
energy system.
24. A method as claimed in claim 22 wherein said worksite includes
non-flat terrain, said energy collection unit is one of a plurality
of energy collection units of said solar energy system, and said
redistributing operation comprises: excavating said non-flat
terrain to create terraces; and forming a plurality of earthen
structures on said terraces for arranging said plurality of energy
collection units thereupon.
25. A method as claimed in claim 22 further comprising encasing
said earthen structure in a binder material.
26. A method as claimed in claim 22 further comprising
incorporating a non-earthen strengthening material internal to said
earthen structure, said non-earthen strengthening material being
detached from said solar energy collection unit.
27. A method of supporting a photosynthetic bioreactor of a solar
energy system comprising: redistributing earth at a worksite to
form an elevated earthen structure having a sun facing surface;
orienting said sun facing surface at an elevation angle from
horizontal of greater than ten degrees and less than ninety
degrees; compacting said earthen structure; providing a channel
proximate said earthen structure; arranging said photosynthetic
bioreactor upon said sun facing surface of said earthen structure;
directing a supply fluid through said channel; and supplying a
fluid inlet of said photosynthetic bioreactor with said supply
fluid from said channel.
28. A method as claimed in claim 27 further comprising forming said
sun facing surface to have a first surface area at least as great
as a second surface area of said photosynthetic bioreactor.
29. A method as claimed in claim 27 wherein said photosynthetic
bioreactor comprises enclosed members, and said arranging operation
comprises aligning a longitudinal axis of each of said enclosed
members with a slope of said sun facing surface.
30. A method as claimed in claim 27 wherein said channel is a first
channel, and said method further comprises: providing a second
channel proximate said earthen structure; supplying said second
channel with a release fluid from a fluid outlet of said
photosynthetic bioreactor; and directing said release fluid through
said second channel.
31. A method as claimed in claim 27 wherein said solar energy
system includes a plurality of photosynthetic bioreactors, and said
redistributing operation comprises excavating said worksite to form
a plurality of elevated earthen structures for supporting said
plurality of photosynthetic bioreactors.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to the field of solar energy
systems. More specifically, the present invention relates to a
stable structure for supporting a solar energy collection unit of a
solar energy system.
BACKGROUND OF THE INVENTION
[0002] Due to the finite supply of fossil energy sources, the
global environmental damage caused by fossil fuels, increasing
energy demand, and economic forces, society is becoming compelled
to diversify energy resources, utilize existing fossil fuels more
effectively, and reduce pollutants. An alternative energy resource,
solar power, is already in widespread use where other supplies of
power are absent such as in remote locations and in space. Solar
power generally describes a number of methods of harnessing energy
from the light of the sun.
[0003] Solar power technologies can be classified as either direct
or indirect. Direct solar power involves only one transformation
into a usable form. Direct solar power utilizes solar energy
collection units such as photovoltaic cells for creating
electricity, solar thermal collectors for creating heat energy,
solar sails for imparting motion, fiber optic cables for conducting
sunlight into building interiors to create supplemental lighting,
and so forth.
[0004] Indirect solar power involves more than one transformation
to reach a usable form. An exemplary type of power generation that
employs indirect solar power is the use of photosynthesis to
convert solar energy to chemical energy which can later be burned
as fuel. The concept of using photosynthesis to convert solar
energy to chemical energy has been expanded into using algae to
convert carbon dioxide from waste emissions to useful, high-value
biomass products. This methodology is generally referred to as
carbon dioxide bio-regeneration. Early ventures entailed pumping
emission gases through the base of a pond and growing algae on the
surface. Unfortunately, the algae was difficult to harvest and the
energy required to "churn" the pond to ensure full algal exposure
to sunlight was expensive. More recent efforts have been directed
toward enclosed bioreactor systems that function as solar energy
collection units, with the object being to increase algae
production in a cost-effective manner. Such innovations in
bioreactor systems involve streamlining the harvesting of algae,
limiting the energy required to operate the system, automating
necessary controls (e.g. flow controllers and gas uptake),
minimizing the physical space requirements, and so forth. Such
innovations have increased the economic viability of utilizing
indirect solar power for carbon dioxide regeneration.
[0005] Although solar collection efficiency has increased and the
costs for the various solar energy collection units, such as
photovoltaic cells, thermal collectors, fiber optic elements, algal
bioreactors, and the like is decreasing through technological
innovation, the cost effectiveness of the host support structures
is not correspondingly decreasing.
[0006] Such host support structures must secure the solar energy
collection units in order to withstand climatic stresses such as,
wind, rain, sand storms, floods, snow, and the like. The host
support structures must also secure the solar energy collection
units in order to withstand geologic stresses including
earthquakes, erosion, and the like.
[0007] In order to withstand the various climatic and geologic
stresses, prior art support structures for solar energy collection
units require a heavy structural steel pedestal or framework,
typically embedded in a large concrete base or foundation. Typical
installations have become sufficiently large so that cranes are
required to move and install the structural steel, cement is
trucked in to support the steel framework, and multiple visits to
the site by multiple workers are required to complete the
installation. Unfortunately, the construction of such a large
structure is quite expensive, is difficult to install in remote
locations, and is expensive to maintain.
[0008] Consequently, a major obstacle to a more widespread
exploitation of both direct and indirect solar power technologies
has been the development of stable, yet cost-effective, host
structures for supporting solar energy collection units in
alignment with incident rays of the sun.
SUMMARY OF THE INVENTION
[0009] Accordingly, it is an advantage of the present invention
that a method of supporting a solar energy collection unit of a
solar energy system is provided.
[0010] Another advantage of the present invention is that a method
of supporting a solar energy collection unit is provided that
allows the use of local materials to support the solar energy
collection unit.
[0011] Yet another advantage of the present invention is that a
method of supporting a solar energy collection unit is provided
that is readily customizable, stable under stress conditions, cost
effective to build and maintain, and has a minimal long term impact
on the local environment.
[0012] The above and other advantages of the present invention are
carried out in one form by a method of supporting a solar energy
collection unit of a solar energy system. The method calls for
redistributing earth at a worksite to form an elevated earthen
structure having a sun facing surface, compacting the earthen
structure, and arranging the solar energy collection unit upon the
sun facing surface of the earthen structure.
[0013] The above and other advantages of the present invention are
carried out in another form by a method of supporting a
photosynthetic bioreactor of a solar energy system. The method
calls for redistributing earth at a worksite to form an elevated
earthen structure having a sun facing surface, orienting the sun
facing surface at an angular elevation from horizontal of greater
than ten degrees and less than ninety degrees, and compacting the
earthen structure. The method further calls for excavating a
channel proximate the earthen structure and arranging the
photosynthetic bioreactor upon the sun facing surface of the
earthen structure. A supply fluid is directed through the channel
and a fluid inlet of the photosynthetic bioreactor is supplied with
the supply fluid from the channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] A more complete understanding of the present invention may
be derived by referring to the detailed description and claims when
considered in connection with the Figures, wherein like reference
numbers refer to similar items throughout the Figures, and:
[0015] FIG. 1 shows a block diagram of an exemplary perspective
view of a solar energy system having a plurality of solar energy
collection units supported by elevated earthen structures at a
worksite;
[0016] FIG. 2 shows a side view of one of the elevated earthen
structures having internal strengthening material and encased in a
binder material;
[0017] FIG. 3 shows a side view of one of the exemplary elevated
earthen structures oriented to provide shade for a portion of the
solar energy system;
[0018] FIG. 4 shows a side view of one of the exemplary elevated
earthen structures including a fluid supply channel and a fluid
release channel for a photosynthetic bioreactor solar energy
system;
[0019] FIG. 5 shows a perspective view of one of the earthen
structures supporting a plurality of tubular photosynthetic
bioreactors;
[0020] FIG. 6 shows a partial sectional view of one of the earthen
structures and one of the tubular photosynthetic bioreactors at
section lines 6-6 of FIG. 5;
[0021] FIG. 7 shows a partial side view of a plurality of earthen
structures formed at a worksite on non-flat terrain;
[0022] FIG. 8 shows a partial side view of horizontally arranged
solar energy collection units supported by a plurality of earthen
structures formed at a worksite on non-flat terrain;
[0023] FIG. 9 shows a partial front view of the tubular solar
energy collection units and earthen structures of FIG. 8;
[0024] FIG. 10 shows a flowchart of an installation process for
supporting a solar energy collection unit in accordance with a
preferred embodiment of the present invention; and
[0025] FIG. 11 shows a block diagram of a top view of a portion of
an exemplary solar energy system configured in accordance with the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The present invention relates to methods of supporting a
solar energy collection unit of a solar energy system. The solar
energy system encompasses a variety of direct and indirect solar
power technologies. Similarly, the solar energy collection unit
encompasses a variety of existing and emerging apparatuses such as
a photovoltaic cell, a thermal collector, a fiber optic collector,
an enclosed photosynthetic bioreactor, and the like. In certain
embodiments, the disclosed methods of supporting a solar energy
collection unit provided herein can be utilized as part of an
integrated photosynthetic bioreactor solar energy system that at
least partially converts certain pollutant compounds, such as
carbon dioxide, contained within combustion gases to biomass.
[0027] The term "photosynthetic bioreactor" used herein refers to
an apparatus containing, or configured to contain, a liquid medium
carrying at least one species of photosynthetic organism and having
at least one surface of which is transparent to light of a
wavelength capable of driving photosynthesis. The terms
"photosynthetic organism" or "biomass," used herein includes those
organisms capable of photosynthetic growth, such as plant cells and
micro-organisms (including algae and euglena). The term "biofuel"
used herein includes any fuel that derives from biomass produced in
the photosynthetic bioreactor.
[0028] FIG. 1 shows a block diagram of an exemplary perspective
view of a solar energy system 20 having a plurality of solar energy
collection units 22 supported by elevated earthen structures 24 at
a worksite 26. Solar energy collection units 22 are arranged on a
sun facing surface 28 of earthen structures 24. Sun facing surface
28 is that side of earthen structure 24 that is exposed to a
sufficient duration of sunlight for solar energy collection. Sun
facing surface 28 has a surface area at least as great as the
surface area of the one or more solar energy collection units 22,
so that earthen structures 24 fully support units 22. The present
invention involves methodology for supporting solar energy
collection units 22 by utilizing earthen structures 24 in lieu of a
heavy structural steel pedestal or framework embedded in a large
concrete base or foundation.
[0029] Solar energy collection units 22 in this exemplary
illustration may be photovoltaic cells, thermal collectors, and the
like. Consequently, solar energy system 20 may include other
supporting equipment, for example, wiring, charge controllers,
batteries, inverters, and the like, not shown herein for simplicity
of illustration. In addition, only three earthen structures 24 are
shown for simplicity of illustration. It should be understood that
the quantity of earthen structures can be readily scaled to
accommodate a quantity of solar energy collection units 22 that
form system 20.
[0030] Earthen structures 24 are formed utilizing the local
material at worksite 26, such as sand, soil, rock, mud, and various
densities of earthen blends. Such an arrangement can be built
utilizing conventional earth-moving equipment, such as graders,
shovels, excavators, and the like to redistribute the local
material to host solar energy collection units 22. In addition,
since local material is simply redistributed to support solar
energy collection units 22, a great array of designs for plowing
and/or excavating worksite 26 are envisioned that capitalize on the
geography of worksite 26, and accommodate large scale solar energy
systems. That is, alignment and realignment of solar energy
collection units 22 can be accomplished by simply reshaping host
earthen structures 24 and repositioning solar energy collection
units 22 upon them.
[0031] Since earthen structures 24 are constructed utilizing local
materials, earthen structures 24 can be installed in a variety of
locations. Preferably, worksite 26 is non-arable, thereby saving
arable land for agriculture, while effectively utilizing heretofore
unused land. Earthen structures 24 may host low profile indigenous
plant life to further stabilize earthen structures 24 and to create
a more natural, aesthetically pleasing appearance. Consequently,
earthen structures 24 of solar energy system 20 may be more readily
accepted by the general public.
[0032] The use of local earthen materials in building earthen
structures 24 provides for more efficient, time effective
installation, thus decreasing setup costs. Moreover, earthen
structures 24 can be repaired with materials in direct proximity to
the installation, lowering maintenance costs and accelerating time
to operation. Furthermore, the use of local earthen materials
allows decommissioning of the installation with minimal
environmental impact because the local materials can be returned to
their natural position.
[0033] FIG. 2 shows a side view of elevated earthen structure 24
having internal strengthening material 32 and encased in a binder
material 34. Strengthening material 32 may be non-earthen material,
such as wood, plastic, metal, or composites. Binder material 34 may
be formed from mud, clay, adobe, or some other sun-dried or
sun-dryable locally available material.
[0034] Evaluation of worksite 26 may reveal that the earthen
support structures for solar energy collection units 22 may require
additional strengtheners for assuring overall structural integrity.
Non-earthen strengthening material 32 may optionally be
incorporated into earthen structure 24 to provide this additional
strength to earthen structure 24. In a preferred embodiment,
non-earthen strengthening material 32 is detached from solar energy
collection unit 22. This allows ready reconfiguration and/or
replacement of units 22 without having to access material 32 by
partially or totally destroying earthen structure 24. Non-earthen
strengthening material 32 in a triangular configuration is
presented for simplicity. Those skilled in the art will recognize
that strengthening material 32 can be any of a great variety of
sizes, shapes, and densities.
[0035] Further evaluation of worksite 26 may reveal that the
earthen structures may be subject to erosion from dust storms,
rains, flooding, and the like. Earthen structure 24 may optionally
be encased in binder material 34 to assure surface integrity and
robustness in the face of erosive action of wind or water.
[0036] It should be noted that sun facing surface 28 of earthen
structure 24, and the other earthen structures constructed in
accordance with the present invention, is oriented at an elevation
angle 36 from horizontal of greater than ten degrees and less than
ninety degrees. The degree of elevation angle 36 is determined to
suit the particular sun exposure requirements of solar energy
collection units 22 so as to optimize the energy output of units
22.
[0037] FIG. 3 shows a side view of exemplary elevated earthen
structure 24 oriented to provide shade for a portion of solar
energy system 20, such as electronic equipment 40. Electronic
equipment 40 may encompass elements, such as wiring, charge
controllers, batteries, inverters, and the like, for solar energy
system 20. As shown, electronic equipment 40 is positioned on the
side of earthen structure 24 away from sun facing surface 28.
Consequently, earthen structure 24 is generally shaded by a shadow
42 cast by earthen structure 24. Proper positioning of electronic
equipment 40 in shadow 42 protects equipment 40 from the degrading
effects of prolonged sun exposure and relieves heat stress on
equipment 40. Alternatively, a separate earthen shade structure
(not shown) may be formed through the redistribution of local
materials.
[0038] It should be further noted that earthen structure 24
provides a thermal management service to solar energy system 20
(FIG. 1). Earthen structure 24 has large mass and can absorb and
sink excess heat loads off the elements of solar energy system 20
that have susceptibility to high heat stress. Thus, use of earthen
structure 24 to assist the thermal management of system 20 provides
a passive, high reliability, and cost efficient method to relieve
cumulative and peaking heat loads on solar energy collection units
22 and electronics that are used in solar energy system 20.
[0039] Heat may be dumped directly to earthen structure 24 by
burying a tab 44 or heat pipe mechanism from the bezel or frame of
solar energy collection units 22 into earthen structure 24. When
solar energy collection units 22 are thermal collectors, working
fluids that are intentionally heated in units 22 can be optionally
routed via enclosed piping through the surface of earthen structure
24 (not shown). Consequently, the working fluids are insulated by
earthen structure 24 preserving the energy efficiency of the
overall system during cooler portions of the day or night.
[0040] FIG. 4 shows a side view of exemplary elevated earthen
structure 24 including a fluid supply channel 48 and a fluid
release channel 50 for a photosynthetic bioreactor solar energy
system 52. System 52 includes solar energy collection units in the
form of enclosed photosynthetic bioreactors 54, of which one is
visible, and earthen structure 24 supports photosynthetic
bioreactors 54.
[0041] In general, photosynthetic bioreactors 54 contain a liquid
medium carrying a photosynthetic organism, for example, algae, and
have a transparent surface 56 for driving photosynthesis. The algae
in photosynthetic bioreactor solar energy system 52 absorb carbon
dioxide from a source, in the presence of solar energy, through the
production of cell mass. The source of carbon dioxide may be
combustion gas, i.e., flue gas, produced by fossil fuel users, such
as coal, oil, and gas plants. The algal biomass can be harvested
from photosynthetic bioreactors 54 for creating biofuel,
pharmaceuticals, cosmetics, and so forth. Those skilled in the art
of algal biotechnology will recognize that some algal cultures can
also be used in photosynthetic bioreactors 54 for biological
removal of nitrogen compounds found in flue gases.
[0042] A particular configuration of photosynthetic bioreactors 54
is not a limitation of the present invention. Rather,
photosynthetic bioreactors 54 can be any of a variety of
conventional and emerging photosynthetic bioreactor configurations,
including "bubble columns" or "air lift reactors," that are
supportable by earthen structure 24. The liquid medium contained in
photosynthetic bioreactors 54 is typically water. However, the
water need not be potable, but may be sea water, brackish water, or
other non-potable locally obtained water containing sufficient
nutrients to facilitate viability and growth of algae contained
within the liquid medium.
[0043] In a preferred embodiment, the methodology of the present
invention entails providing fluid supply channel 48 and/or fluid
release channel 50 by excavating earth at worksite 26 proximate
earthen structure 24. A supply fluid, i.e., water, represented by
an arrow 58, is directed through fluid supply channel 48, and is
supplied to a fluid inlet 60 of each of photosynthetic bioreactors
54. A release fluid, represented by an arrow 62, is supplied to
fluid release channel 50 from a fluid outlet 64 of each of
photosynthetic bioreactors 54, and is directed through fluid
release channel 50. Release fluid 62 contains water and a
concentrated amount of biomass. This biomass can be harvested at
the location of fluid outlet 64, or alternatively, at a centralized
algal collector (not shown) in fluid communication with fluid
release channel 50.
[0044] Fluid channels 48 and 50 provide a system for channeling
fluid to and from photosynthetic bioreactors 54, thus saving on
expenses associated with piping and pipe installation. Of course,
those skilled in the art will recognize that fluid channels 48 and
50 can be excavated with a slope that further facilitates fluid
flow in the desired direction. In addition, since fluid channels 48
and 50 may be open, water flow from rain and snow can be collected
in fluid channels 48 and 50 for use within photosynthetic
bioreactors 54. The water flow collected in fluid channels 48 and
50 may also support co-located plant growth 66 at worksite 26 or
patching of a worn structure with mud or adobe.
[0045] In an alternative embodiment, fluid supply channel 48 and
fluid release channel 50 may be provided in the form of enclosed
tubular members, i.e., pipes, that can be buried or can lie above
ground. The enclosed tubular members may be in various
cross-sectional shapes, such as circular, rectangular, oval,
crescent, and so forth, in accordance with the particular
configuration of the solar energy system. The enclosed tubular
members may be transparent or transparent for specific light
wavelength to optimize growth of algal biomass.
[0046] In an exemplary embodiment, photosynthetic bioreactor solar
energy system 52 may be a large scale operation at worksite 26
covering at least one hundred acres. Substantially an entirety of
worksite 36 may then be utilized to form a plurality of elevated
earthen structures 24 for supporting a plurality of photosynthetic
bioreactors 54, or other such solar energy collection units.
Efficient algae production in concert with cost effective
installation and maintenance of earthen support structures 24
facilitate the economical production of large quantities of biomass
while advantageously reducing pollutant materials in combustion
gases.
[0047] Referring to FIGS. 5-6, FIG. 5 shows a perspective view of
earthen structure 24 supporting a plurality of tubular
photosynthetic bioreactors 54, and FIG. 6 shows a partial sectional
view of earthen structure 24 and one of tubular photosynthetic
bioreactors 54 at section lines 6-6 of FIG. 6. Tubular
photosynthetic bioreactors 54 are arranged on earthen structure
such that a longitudinal axis 67 of each of bioreactors 54 is
aligned with the slope of elevated sun facing surface 28 of earthen
structure 24.
[0048] The methodology of the present invention entails conforming
sun facing surface 28 of earthen structure 24 to a shape of the
solar energy collection unit, in this case tubular photosynthetic
bioreactors 54. This is especially evident in FIG. 6 in which a
trough 68 has been excavated to accommodate one of photosynthetic
bioreactors 54. The conformed earthen structure 24 with troughs 68
retains tubular photosynthetic bioreactors 54 in place thereby
creating stable retention of bioreactors 54 and optimizing their
exposure to sunlight, and facilitating thermal management of the
liquid medium circulating in bioreactors 54. Photosynthetic
bioreactors 54 are illustrated herein as being generally circular
in cross-section for simplicity of illustration. However, it should
be understood that photosynthetic bioreactors 54 may be in other
cross-sectional shapes, such as rectangular, oval, crescent, and so
forth, in accordance with the particular configuration of the solar
energy system.
[0049] FIG. 7 shows a partial side view of a plurality of earthen
structures 24 formed at worksite 26 on non-flat terrain 72. In
particular, non-flat terrain 72 is excavated to create terraces 74,
and earthen structures 24 are formed on terraces 74. Solar energy
collection units 22 of solar energy system 20 are subsequently
arranged on each of earthen structures 24. The use of earthen
structures 24 readily permits the use of non-flat terrain 72 for
solar energy system 22. Terraces 74 made of local, earthen material
may be built, e.g. plowed or excavated, in a manner that allows
solar energy collection units 22 to be hosted on hills, valley
sides, or in gullies. This technique may allow the use of a greater
number of solar energy collection units 22 on a smaller footprint
than on flat terrain, again increasing economic efficiency of solar
energy system 20.
[0050] Referring to FIGS. 8 and 9, FIG. 8 shows a partial side view
of horizontally arranged solar energy collection units 76 of a
solar energy system 78. Solar energy collection units 76 are
supported by a plurality of earthen structures 24 formed at
worksite 26 on non-flat terrain 72. FIG. 9 shows a partial front
view of horizontally arranged tubular solar energy collection units
76 and earthen structures 24. As explained in connection with FIG.
7, non-flat terrain 72 is excavated to create terraces 74, and
earthen structures 24 are formed on terraces 74 in a manner that
allows solar energy collection units 76 to be hosted on hills,
valley sides, or in gullies thereby allowing the use of a greater
number of solar energy collection units 22 on a smaller footprint
than on flat terrain.
[0051] In this exemplary configuration, each of horizontally
arranged solar energy collection units 76 on each of terraces 74 is
interconnected via a feeder tube 80, and adjacent terraces 74 are
sloped in opposing directions. A supply fluid, such as water,
represented by an arrow 82, is supplied to a fluid inlet 84 of a
first, or highest, one of solar energy collection units 76 via, for
example, fluid supply channel 48 (FIG. 4). Supply fluid 82 flows
downwardly through successive solar energy collection units 76 and
feeder tubes 80 under the influence of gravity. A release fluid,
represented by an arrow 86, is eventually released at a fluid
outlet 88 from a last, or lowest, one of solar energy collection
units 76 to, for example, fluid release channel 50 (FIG. 4).
[0052] Solar energy system 78 having horizontally arranged solar
energy collection units 76 may be a heat gather or may
alternatively be a photosynthetic bioreactor. When solar energy
system 78 is configured as a heat gatherer, supply fluid 82 is
heated as it flows through solar energy collection units 76, and
hot release fluid 86 is released at a fluid outlet 88. When solar
energy system 78 is configured as a photosynthetic bioreactor,
release fluid 86 can contain water and a concentrated amount of
biomass. This biomass can be harvested at the location of fluid
outlet 88, or alternatively, at a centralized algal collector (not
shown) in fluid communication with fluid outlet 88.
[0053] As most clearly seen in FIG. 8, each of earthen structures
24 may be configured to include a trough 90 or a generally
parabolic surface. Each trough 90 cradles one of solar energy
collection units 76 for retention and stability of units 76. In
addition, troughs 90 can function to concentrate solar energy
toward solar energy collection units 76. To enhance this
concentration of solar energy, each trough 90 may be lined with a
mirrored surface using, for example, polished aluminum.
[0054] Solar energy collection units 76 are shown as being
generally circular in cross-section for simplicity of illustration.
However, it should be understood that solar energy collection units
76 may be in various other cross-sectional shapes, such as
rectangular, oval, crescent, and so forth, in accordance with the
particular configuration of solar energy system 78.
[0055] FIG. 10 shows a flowchart of an installation process 92 for
supporting a solar energy collection unit in accordance with a
preferred embodiment of the present invention. In light of the
various custom configurations described in connection with FIGS.
1-9, FIG. 10 generalizes tasks performed to develop worksite 26 to
support solar energy collection units 22 and/or solar energy
collection units in the form of photosynthetic bioreactors 54 and
horizontally arranged solar energy collection units 76 on earthen
structures 24.
[0056] It should be observed that installation process 92 includes
some task boxes formed from solid lines and other task boxes formed
from dashed lines. The task boxes formed from solid lines represent
those tasks required for any earthen structure configuration,
whereas the task boxes formed from dashed lines represent optional
tasks that are dependent upon worksite geography and the particular
solar energy system configuration.
[0057] Process 92 begins with a task 94. Task 94 is an initial step
in which requirements of the particular solar energy system are
defined and the earthen structure configuration is determined. The
particular configuration for earthen structures 24 depends in large
part upon local geography, size and quantity of the solar energy
collection units, desired elevation angle for the units, and
whether fluid supply and release channels are required.
[0058] Once certain configuration decisions have been made,
installation process 92 proceeds to a task 96 at which graders,
shovels, excavators, and the like are employed to redistribute
earth at worksite 26 (FIG. 1) to form the particular elevated
earthen structure.
[0059] Optional tasks 98 and 100 may be performed in connection
with task 80. At task 98, internal strengthening material 32 (FIG.
2) may be incorporated into earthen structure 24. At task 100,
fluid supply channel 48 (FIG. 4) and/or fluid release channel 50
(FIG. 4) may be provided through excavation at worksite 26 or by
installing enclosed members, i.e., piping.
[0060] Next, a task 102 is performed regardless of the particular
configuration of earthen structure 24. At task 102, the
redistributed earth used to form earthen structure 24 is compacted
to form a stable structure.
[0061] Following task 102, an optional task 104 may be performed.
At task 104, the surface and surrounding area of the recently
compacted earthen structure 24 may be stabilized. For example,
earthen structure 24 may be encased with binder material 34 (FIG.
2) and/or plant life may be installed around earthen structure 24
for vegetation control. Following either of tasks 102 or 104, a
task 106 is performed.
[0062] At task 106, solar energy collection units 22 (FIG. 1),
photosynthesis bioreactors 54 (FIG. 4), or horizontally arranged
solar energy collection units 76 (FIG. 8) are arranged upon sun
facing surface 28 of earthen structures 24. That is, the solar
energy collection units are laid upon earthen structures 24 without
the encumbrance and associated installation complexity and cost of
structural steel supports and concrete foundations.
[0063] An optional task 108 is performed if fluid medium is
utilized in connection with the particular solar energy system
configuration, such as photosynthesis bioreactor solar energy
system 52 (FIG. 4) or solar energy system 78 (FIG. 8). At task 108,
when a fluid medium is utilized, fluid supply and release systems
are configured. Configuration entails, for example, providing
supply fluid 58 (FIG. 4), adjusting fluid valves, and/or activating
any intervening fluid pumps.
[0064] In addition to optional task 108, or in lieu of optional
task 108, an optional task 110 is performed. At optional task 110,
electronic equipment 40 (FIG. 3) may be configured. Configuration
entails, for example, positioning electronic equipment 40 in shadow
42 (FIG. 3) of earthen structures 24 and making the necessary
connections to solar energy collection units 22. Installation
process 92 ends following task 110.
[0065] FIG. 11 shows a block diagram of a top view of a portion of
an exemplary solar energy system configured in accordance with the
present invention. More specifically, the exemplary solar energy
system is photosynthetic bioreactor solar energy system 52 in which
photosynthetic bioreactors 54 are arranged on earthen structures
24. FIG. 11 is presented to illustrate a channel structure, either
open or enclosed piping, that may be efficiently implemented to
provide supply fluid 58 via fluid supply channel 48 to each of a
plurality of photosynthetic bioreactors 54, and to remove release
fluid 62 via fluid release channel 50 from each of photosynthetic
bioreactors 54.
[0066] Photosynthetic bioreactor solar energy system 52 optionally
includes a primary valve 112 that enables recirculation of release
fluid 62 into fluid supply channel 48. In such a situation, biomass
in release fluid 62 may be harvested so that release fluid 62 can
be reused, thereby conserving the working fluid. System 52 may
further optionally include secondary valves 114 for controlling a
flow of supply fluid 58 into individual photosynthetic bioreactors
54, so that individual bioreactors 54 can be taken offline for
maintenance, replacement, and so forth.
[0067] Each of photosynthetic bioreactors 54 further includes a
combustion gas inlet 116 in which combustion gas, represented by
dashed arrows 118, is received into bioreactors 54. Combustion gas
118 bubbles up from the bottom of photosynthetic bioreactors 54 and
supply fluid 58 flows downwardly in an opposing direction from
combustion gas 118. Carbon dioxide, and/or other pollutant
materials, in combustion gas 118 is converted to organic material
in photosynthetic reactions occurring in bioreactors 54. Combustion
gas 118 is subsequently released from photosynthetic bioreactors 54
through a gas outlet 120, with ideally a significant reduction in
pollutant materials.
[0068] In summary, the present invention teaches of a method of
supporting a solar energy collection unit of a solar energy system.
The method entails the redistribution of local earthen materials to
form an earthen structure upon which the solar energy collection
unit is arranged. The methodology of excavating and redistributing
local materials yields earthen support structures that are highly
customizable, are cost effective to build and maintain, and have a
minimal long term impact on the local environment. Moreover, the
methodology of the present invention yields a stable support
structure for solar energy collection units with the associated
installation complexity and cost of conventional structural steel
supports and concrete foundations. The incorporation of internal
strengthening materials into the earthen structures and/or the
encasement of the earthen structures in binder material enhance
surface integrity and overall stability under stress conditions. In
addition, the earthen structures can provide thermal management
services to the solar energy systems, and channels can be readily
provided at the worksite for supply and release channeling of a
fluid medium used by the solar energy system.
[0069] Although the preferred embodiments of the invention have
been illustrated and described in detail, it will be readily
apparent to those skilled in the art that various modifications may
be made therein without departing from the spirit of the invention
or from the scope of the appended claims.
* * * * *