U.S. patent application number 13/363231 was filed with the patent office on 2012-05-24 for concentrating module and method of manufacture for photovoltaic strips.
This patent application is currently assigned to Solaria Corporation. Invention is credited to Kevin R. GIBSON.
Application Number | 20120125049 13/363231 |
Document ID | / |
Family ID | 40071274 |
Filed Date | 2012-05-24 |
United States Patent
Application |
20120125049 |
Kind Code |
A1 |
GIBSON; Kevin R. |
May 24, 2012 |
CONCENTRATING MODULE AND METHOD OF MANUFACTURE FOR PHOTOVOLTAIC
STRIPS
Abstract
A glass concentrator for manufacture of solar energy conversion
module is provided including a webbing that has a load sustenance
characteristic and a hail impact resistance characteristic based on
a first thickness of the webbing. The concentrator also includes a
plurality of elongated concentrating elements integrally formed
with the webbing. Each of the elongated concentrating elements has
an aperture region, an exit region and two side regions, which
bears a geometric concentration characteristic provided by a highly
reflective side regions and an aperture-to-exit. scale ratio in a
range from about 1.8 to about 4.5. The glass concentrator can be
attached with a plurality of photovoltaic strips cumulatively on
each and every exit regions and clamped with a rigid or flexible
back cover member to form a solar concentrator module for
converting sunlight to electric energy. The solar concentrator
module based on certain embodiments meets the industrial
qualification standards.
Inventors: |
GIBSON; Kevin R.; (Redwood
City, CA) |
Assignee: |
Solaria Corporation
Fremont
CA
|
Family ID: |
40071274 |
Appl. No.: |
13/363231 |
Filed: |
January 31, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12121788 |
May 16, 2008 |
8119902 |
|
|
13363231 |
|
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|
60939089 |
May 21, 2007 |
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Current U.S.
Class: |
65/65 |
Current CPC
Class: |
H01L 31/0547 20141201;
H02S 20/00 20130101; Y02E 10/547 20130101; Y10T 156/10 20150115;
C03B 35/184 20130101; C03B 18/14 20130101; Y02E 10/52 20130101;
B29D 11/00278 20130101 |
Class at
Publication: |
65/65 |
International
Class: |
C03B 18/14 20060101
C03B018/14; C03B 29/00 20060101 C03B029/00; C03B 18/12 20060101
C03B018/12 |
Claims
1. A method for making a glass concentrator for manufacture of
solar energy conversion module, the method comprising: forming a
molten glass; feeding a predetermined amount of the molten glass
into a float bath to form a floating ribbon glass in rectangular
shape defined by a first dimension and a second dimension;
processing the floating ribbon glass to have an even first
thickness between a top surface and a back surface; rolling with a
shaped molding roller across the top snake partially into the first
thickness at a predetermined first temperature within a first time
period to form a plurality of shaped concentrating elements with a
second thickness; annealing the ribbon glass by gradually reducing
temperature from the first temperature to a second temperature
within a second time period; lifting the ribbon glass at the second
temperature onto a plurality of circular rollers; rolling the back
surface of the ribbon glass while continuing cool the ribbon glass
to a third temperature during transportation on the plurality of
circular rollers; flame polishing the plurality of shaped
concentrating elements on the top surface; wherein, the feeding a
predetermined amount of the molten glass comprises controlling the
first thickness to at least 5 mm to possess a characteristic of
sustaining at least a load of 2400 Pa uniformly applied for 1 hour
in two cycles; rolling with a shaped molding roller across the top
surface partially into the first thickness to form a plurality of
shaped concentrating elements with a second thickness comprises
forming a plurality of elongated structures one-next-to-another in
parallel, each of the plurality of elongated structures comprising
a geometrical optical concentrating element with a scale ratio of
an aperture region to an exit region greater than 2.0.
2. The method of claim 1 wherein the forming a molten glass
comprises melting and blending batch materials including sand,
limestone, cerium oxide, iron oxide and salt cake in a furnace.
3. The method of claim 1 wherein the forming a molten glass
comprises forming a polymer in semi-fluidic form.
4. The method of claim 1 wherein the feeding a predetermined amount
of the molten glass into a float bath comprises forming a laminated
structure by alternatively feeding molten glass with different
composition of materials.
5. The method of claim 1 during the rolling with a shaped molding
roller across the top surface further comprises partially
re-shaping the just-formed concentrating element using a localized
water cooling or cryogenic gas cooling.
6. The method of claim 1 wherein the annealing the ribbon glass
comprises cooling the entire ribbon glass via conduction and
convection.
7. The method of claim 1 wherein the flame polishing the plurality
of shaped concentrating elements comprises using a burner
comprising a plurality of gas nozzles to generate a nearly
one-dimensional flames.
8. The method of claim 7 wherein the burner includes a gas supply
tube connected to a pressured gas tank comprising a gas mixture of
hydrogen and oxygen with a predetermined mixing ratio.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims priority of U.S. patent application
Ser. No. 60/939,089, and titled "CONCENTRATING MODULE AND METHOD OF
MANUFACTURE FOR PHOTOVOLTAIC STRIPS," filed by Kevin R. Gibson at
May 21, 2007 commonly assigned, and is incorporated by reference in
its entirety.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH OR DEVELOPMENT
[0002] NOT APPLICABLE
REFERENCE TO A "SEQUENCE LISTING," A TABLE, OR A COMPUTER PROGRAM
LISTING APPENDIX SUBMITTED ON A COMPACT DISK.
[0003] NOT APPLICABLE
BACKGROUND OF THE INVENTION
[0004] The present invention relates generally to solar energy
techniques. In particular, the present invention provides a method
and resulting device for manufacturing the solar energy conversion
system. More particularly, the present invention provides a method
and a structure for manufacture of a sunlight concentrator module
having a glass webbing integrally including a plurality of
concentrating elements coupled with a plurality of photovoltaic
strips. Merely by way of example, the invention has been applied to
solar panels, commonly termed modules, but it would be recognized
that the invention has a much broader range of applicability.
[0005] As the population of the world increases, industrial
expansion has lead to an equally large consumption of energy.
Energy often comes from fossil fuels, including coal and oil,
hydroelectric plants, nuclear sources, and others. As merely an
example, the international Energy Agency projects further increases
in oil consumption, with developing nations such as China and India
accounting for most of the increase. Almost every element of our
daily lives depends, in part, on oil, which is becoming
increasingly scarce. As time further progresses, an era of "cheap"
and plentiful oil is coming to an end. Accordingly, other and
alternative sources of energy have been developed.
[0006] Concurrent with oil, we have also relied upon other very
useful sources of energy such as hydroelectric, nuclear, and the
like to provide our electricity needs. As an example, most of our
conventional electricity requirements for home and business use
comes from turbines run on coal or other forms of fossil fuel,
nuclear power generation plants, and hydroelectric plants, as well
as other forms of renewable energy. Often times, home and business
use of electrical power has been stable and widespread.
[0007] Most importantly, much if not all of the useful energy found
on the Earth comes from our sun. Generally all common plant life on
the Earth achieves life using photosynthesis processes from sun
light. Fossil fuels such as oil were also developed from biological
materials derived from energy associated with the sun. For human
beings including "sun worshipers," sunlight has been essential. For
life on the planet Earth, the sun has been our most important
energy source and fuel for modern day solar energy.
[0008] Solar energy possesses many characteristics that are very
desirable! Solar energy is renewable, clean, abundant, and often
widespread. Certain technologies developed often capture solar
energy, concentrate it, store it, and convert it into other useful
forms of energy.
[0009] Solar panels have been developed to convert sunlight into
energy. As merely an example, solar thermal panels often convert
electromagnetic radiation from the sun into thermal energy for
heating homes, running certain industrial processes, or driving
high grade turbines to generate electricity. As another example,
solar photovoltaic panels convert sunlight directly into
electricity for a variety of applications. Solar panels are
generally composed of an array of solar cells, which are
interconnected to each other. The cells are often arranged in
series and/or parallel groups of cells in series. Accordingly,
solar panels have great potential to benefit our nation, security,
and human users. They can even diversify our energy requirements
and reduce the world's dependence on oil and other potentially
detrimental sources of energy.
[0010] Although solar panels have been used successful for certain
applications, there are still certain limitations. Solar cells are
often costly. Depending upon the geographic region, there are often
financial subsidies from governmental entities for purchasing solar
panels, which often cannot compete with the direct purchase of
electricity from public power companies. Additionally, the panels
arc often composed of silicon bearing wafer materials. Such wafer
materials are often costly and difficult to manufacture efficiently
on a large scale. Availability of solar panels is also somewhat
scarce. That is, solar panels are often difficult to find and
purchase from limited sources of photovoltaic silicon bearing
materials. These and other limitations are described throughout the
present specification, and may be described in more detail
below.
[0011] From the above, it is seen that techniques for improving
solar devices is highly desirable.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention relates generally to solar energy
techniques. In particular, the present invention provides a method
and resulting device for manufacturing the solar energy conversion
system. More particularly, the present invention provides a method
and a structure for manufacture of a sunlight concentrator module
having a glass webbing integrally including a plurality of
concentrating elements coupled with a plurality of photovoltaic
strips. Merely by way of example, the invention has been applied to
solar panels, commonly termed modules, but it would be recognized
that the invention has a much broader range of applicability.
[0013] In a specific embodiment, the present invention provides a
concentrator for manufacture of solar energy conversion module. The
concentrator includes a webbing having a shape characterized by a
first dimension, a second dimension, and a planar region defined by
the first dimension and the second dimension. The webbing has a
front region, a back region, and a first thickness provided between
the front region and the back region. Additionally, the
concentrator includes a load sustenance characteristic from the
first thickness of the webbing. The load is at least of 2400 Pa
uniformly applied on the front region for 1 hour in two cycles. The
concentrator further includes a hail impact resistance
characteristic of the webbing. The impact hail is an ice ball with
at least of 25 mm diameter directed at a speed of at least 23 meter
per second to at least 11 locations of the front region. Moreover,
the concentrator includes a plurality of elongated concentrating
elements integrally formed with the back region one-next-to-another
in parallel along the first dimension. Each of the elongated
concentrating elements having a length, an aperture region, an exit
region, a first side region provided between a first portion of the
aperture region and a first portion of the exit region, a second
side region provided between a second portion of the aperture
region and a second portion of the exit region, and a second
thickness provided between the aperture region and the exit region.
The length of the concentrating element is substantially the same
as the second dimension. The concentrator further includes a
geometric optical concentration characteristic provided by a scale
ratio of the aperture region to the exit region for each of the
plurality of elongated concentrating elements. The scale ratio is
characterized by a range from about 1.8 to about 4.5. Furthermore,
the concentrator includes an optical transparency characteristic of
the first thickness of the webbing combined with the second
thickness of each of the plurality of concentrating elements with a
transmissivity being at least of 90 percent and greater within a
visible light range. Of course, there can be other variations,
modifications, and alternatives. For example, the webbing can be a
glass or a plastic.
[0014] In an alternative specific embodiment, the invention
provides a sunlight concentrator module for manufacture of solar
energy conversion system. The solar concentrator module including a
webbing having a shape characterized by a first dimension, a second
dimension, a planar region defined by the first dimension and the
second dimension. The webbing has a front region, a back region,
and a first thickness of about 3 mm to about 9 mm measured between
the front region and the back region. Additionally, the module
includes a load sustenance characteristic provided by the first
thickness of the webbing. The load is at least of 2400 Pa uniformly
applied on the front region for 1 hour in two cycles. The module
further includes a hail impact resistance characteristic of the
webbing with the first thickness. The impact hail can be an ice
ball with at least of 25 mm diameter directed at a speed of at
least 23 meter per second to at least 11 locations of the front
region. Moreover, the module includes a plurality of concentrator
elements integrally formed with the back region excluding a
peripheral region of the webbing. Each of the concentrator elements
is disposed one-next-to-another in parallel along the first
dimension and characterized by a length, an aperture region, an
exit region, a first side region provided between a first portion
of the aperture region and a first portion of the exit region, a
second side region provided between a second portion of the
aperture region and a second portion of the exit region, and a
second thickness of about 1.8 mm provided between the aperture
region and the exit region. The length of the concentrating element
is substantially the same as the second dimension. The module also
includes a geometric concentration characteristic provided by a
scale ratio of the aperture region to the exit region for each of
the plurality of concentrator elements. The scale ratio is in a
range from about 1.8 to about 4.5. The module further includes an
Optical transparency characteristic of the first thickness of the
webbing combined with the second thickness of each of the plurality
of concentrating elements with a transmissivity being at least of
90 percent and greater within a visible light range. The module
still includes a plurality of photovoltaic strips. Each of the
plurality of photovoltaic strips is coupled to at least a portion
of each of the exit region of the plurality of concentrator
elements. Each photovoltaic strip has a width substantially similar
to the exit region. One or more photovoltaic strips have a
cumulative length substantially similar to the length of the
concentrator element. Furthermore, the module includes a plurality
of electric conducting leads disposed along two edges of each of
the plurality of photovoltaic strips. Each of the plurality of
conducting leads is conductively connected to each other and to
module external electrical ports. The module further includes
either a rigid back cover or a flexible backsheet configured to
mechanically couple with the webbing at the peripheral region.
[0015] In yet still an alternative embodiment, the present
invention includes a method of making a glass concentrator for
manufacture of solar energy conversion module. The method includes
forming molten glass. The method then includes feeding a
predetermined amount of the molten glass into a float bath to form
a floating ribbon glass in rectangular shape defined by a first
dimension and a second dimension, and processing the floating
ribbon glass to have an even first thickness between a top surface
and a back surface. Additionally, the method includes rolling with
a shaped molding roller across the top surface partially into the
first thickness of the floating ribbon glass at a predetermined
first temperature within a first time period to form a plurality of
shaped concentrating elements with a second thickness. The method
further includes annealing the ribbon glass by gradually reducing
temperature from the first temperature to a second temperature
within a second time period. The method further includes lifting
the ribbon glass at the second temperature onto a plurality of
circular rollers and rolling the back surface while continuing cool
the ribbon glass to a third temperature during transportation on
the plurality of circular rollers. The method also includes flame
polishing the plurality of shaped concentrating elements on the top
surface.
[0016] In a further alternative embodiment, the invention also
provides a method of making a glass concentrator for manufacture of
solar energy conversion module. The method includes forming a
ribbon glass characterized by a first thickness between a top
surface and a back surface. The method further includes rolling
with a shaped molding roller across the top surface partially into
the first thickness of the ribbon glass at a first temperature
within a first time period to form a plurality of shaped structures
with a second thickness. Additionally, the method includes
polishing at least partially the plurality of shaped structures on
the top surface. In one embodiment, the first thickness comprises a
characteristic of sustaining at least a load of 2400 Pa uniformly
applied for 1 hour in two cycles. In another embodiment, the
plurality of shaped structures comprises a plurality of
concentrating elements one-next-to-another in parallel. Each of the
plurality of concentrating elements comprises two reflective side
surfaces and a scale ratio of an aperture region to an exit region
being about 2.0 and greater. In yet another embodiment, the two
reflective side surfaces are polished with a root-mean-square
roughness equal to 30 nm or less.
[0017] Still further, the present invention provides a method of
assembling a solar concentrator module. The method includes
preparing a glass concentrator including a webbing. The webbing has
a flat front plane and a back plane occupied entirely by a
plurality of elongated concentrating elements excluding a
peripheral region. Each of the plurality of elongated concentrating
elements has a light-collecting exit region. Additionally, the
method including providing an optical coupling material overlaying
each light-collecting exit region. The method further includes
providing a plurality of photovoltaic strips. Each of the plurality
of photovoltaic strips has two short sides and two long edges. The
two short sides have comparable dimensions as the light-collecting
exit region. The two long edges include a plurality of electric
leads that are inter-connected. Moreover, the method includes
bonding the plurality of photovoltaic strips using at least the
optical coupling material individually and cumulatively to each and
every light-collecting exit region. The method further includes
providing a back cover member comprising a circuit board
electrically coupled with the plurality of electric leads. The back
cover member has a shape substantially matched with the webbing and
an integral uprising edge wall. Furthermore, the method includes
clamping the edge wall with the glass concentrator at the
peripheral region of the webbing. Alternatively, a flexible
backsheet can be used in place of a rigid back cover.
[0018] Many benefits are achieved by way of the present invention
over conventional techniques. For example, the present technique
provides an easy to use process that relies on conventional
technology such as silicon materials in the photovoltaic strips,
although other materials also can be used. Additionally, the method
provides a process that is compatible with conventional process
technology without substantial modifications to conventional
equipment and processes. Preferably, the invention provides for an
improved solar module, which is less costly and easy to handle.
Such solar module uses a single piece of glass webbing integrally
including a plurality of concentrating elements for coupling with a
plurality of photovoltaic strips, which are packaged by coupling a
rigid back cover member around a peripheral region. In a preferred
embodiment, the invention provides a glass concentrator having a
characteristic from the thickness of the glass webbing to sustain a
load of at least 2400 Pa uniformly applied on the webbing surface
for 1 hour in two cycles. Also in a preferred embodiment, the
invention provides a glass concentrator having a geometric
concentration characteristic with an aperture-to-exit scale ratio
in a range from about 1.8 to about 4.5 and polished side regions
with RMS roughness less than 30 nm. The use of concentrator
according to the present invention helps the solar conversion
module having less photovoltaic material per surface area (e.g.,
80% or less, 50% or less) than conventional solar panel module. In
another preferred embodiment, the invention provides a sunlight
concentrator module packaged with a plurality of concentrating
elements integrally formed with the glass webbing and coupled with
a plurality of photovoltaic strips with improved total conversion
efficiency. In still a preferred embodiment, the invention provides
a conducting leads design reducing non-solar-conversion area within
the assembly to enhance the packing factor to 90% or greater. In
one embodiment, the invention provides a solar concentrator module
with a glass webbing as a top cover sealed with a rigid back cover
or a flexible backsheet around the peripheral region. In another
embodiment, the invention provides a solar concentrator module with
a glass webbing as a top cover assembled with a rigid back cover or
a flexible backsheet that is not sealed so as to allow trapped
water vapor breathing out of the photovoltaic region. Depending
upon the embodiment, one or more of these benefits may be achieved.
These and other benefits will be described in more detail
throughout the present specification and more particularly
below.
[0019] Various additional Objects, features and advantages of the
present invention can be more fully appreciated with reference to
the detailed description and accompanying drawings that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a simplified diagram illustrating a perspective
view of a glass concentrator for a solar concentrator module
according to an embodiment of the present invention;
[0021] FIG. 2 is a detailed diagram of a glass concentrator with a
plurality of elongated concentrating elements according to an
embodiment of the present invention;
[0022] FIG. 3 is simplified diagram illustrating a method of making
a glass concentrator according to an embodiment of the present
invention;
[0023] FIG. 4 is a simplified diagram illustrating a concentrating
element with an exit region in reduced width and two side regions
being flame polishing treated according to an embodiment of the
present invention;
[0024] FIG. 5 is a simplified diagram illustrating a method of
assembling a solar concentrator module according to an embodiment
of the present invention;
[0025] FIG. 6 is a simplified diagram illustrating an expanded view
of a solar concentrator module assembly according to an embodiment
of the present invention; and
[0026] FIG. 7 is a simplified diagram illustrating an expanded view
of a solar concentrator module assembly according to an alternative
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention relates generally to solar energy
techniques. In particular, the present invention provides a method
and resulting device for manufacturing the solar energy conversion
system. More particularly, the present invention provides a method
and a structure for manufacture of a sunlight concentrator module
having a glass webbing integrally including a plurality of
concentrating elements coupled with a plurality of photovoltaic
strips. Merely by way of example, the invention has been applied to
solar panels, commonly termed modules, but it would be recognized
that the invention has a much broader range of applicability.
[0028] FIG. 1 is a simplified diagram illustrating a glass
concentrator for a solar concentrator module according to an
embodiment of the present invention. This diagram is merely an
example, which should not unduly limit the scope of the claims
herein. One of ordinary skill in the art would recognize other
variations, modifications, and alternatives. As shown is a
perspective view of a glass concentrator, which is a light
concentrator including a webbing and a plurality of concentrating
elements. The concentrator 100 has a webbing with a top region 101
(not directly seen), back region 103, a first thickness 105 defined
between the top region and the back region, a first dimension 107,
and a second dimension 109. Additionally, a plurality of elongated
concentrating elements 200 is formed integrally with the back
region 103 of the webbing as part of a single piece of glass. In
one embodiment, each of the plurality of elongated concentrating
elements has a length 110 and is disposed one-next-to-another in
parallel extending from one side portion of the webbing to another
side of the webbing. In a specific embodiment, the elongated
concentrating element is parallel to the side of webbing with the
first dimension. In another specific embodiment, the elongated
concentrating element is parallel to the side of webbing with the
second dimension. In yet another embodiment, the plurality of
concentrating elements 200 occupies the entire area of the back
region 103 excluding a peripheral region 115. Of course, there can
be other variations, modifications, and alternatives. The detail
structures of the elongated concentrating element will be described
in specification below.
[0029] In a preferred embodiment, the webbing and the plurality of
concentrating elements are made of a single piece of glass. For
example, this piece of glass comprises mixed batch materials of
sand, limestone, cerium oxide, iron oxide and salt cake. In one
embodiment, the glass comprises a concentration of iron content
about a trace amount and less. In another embodiment, the glass has
cerium oxide at a concentration of about a trace amount and less,
or non-existent. In another preferred embodiment, the glass is a
tempered glass, processed to meet safety standard enforced by
general construction codes. Of course, there can be other
variations, modifications, and alternatives.
[0030] According to another embodiment of the present invention,
the concentrator as shown in FIG. 1 is directly used for
manufacture a solar concentrator module. In particular, the
concentrator has a rectangular shape easy for manufacture and use.
The rectangular shape is characterized by the first dimension 107
and the second dimension 109. In one embodiment, the first
dimension 107 is selected to be about 1 meter or bigger and the
second dimension is correspondingly selected to be about 1.6 meters
or bigger. In another embodiment, with such a size selected above,
the peripheral region 115 of about 10 mm in dimension is selected
for clamping or other packaging purpose. Of course, there can be
other variations, modifications, and alternatives for the
dimensions selected for the concentrator.
[0031] As a preferred embodiment of the present invention, the
concentrator 100 will be directly used as a light receiving top
cover member for the solar conversion module. In order to satisfy
the industry qualification standard regarding to module's
mechanical toughness, the first thickness 105 between the top
region and the back region is selected to be at least 3.2 mm
according to an embodiment of the present invention. For example,
the first thickness can be 5 mm. In another example, the first
thickness can be 6 mm. In yet another example, the first thickness
can be about 7.2 mm or larger. Such the selection of the first
thickness 105 provides an important load sustenance characteristic
and impact hail resistance characteristic to the concentrator of
the solar module, although other factors including the composition
profile, stress profile, packaging method etc also contribute to
these physical characteristics. For example, in one embodiment, the
glass can be replaced by a laminated glass made of polymer which
may provide better impact resistance with a same or smaller
thickness compared to a conventional solar glass.
[0032] According to Industrial Qualification Standards, the solar
module should be able to sustain a load of 2400 Pa uniformly
applied to the surface of the module for 1 hour in two cycles.
Additionally, the solar module should be able to resist a hail
impact represented by an ice ball of 25 mm diameter directed at a
speed of at least 23 meter per second to 11 (random) locations on a
entire surface region of about 1 meter.times.1.6 meter or bigger.
According to certain embodiments, the combination of the selection
of those physical dimensions and compositions of the glass
concentrator result in a satisfaction of all the Industrial
Qualification Standards including the mentioned load test or impact
hail test. For example, Industrial Qualification Standards for
solar module include TEC 61215, IEC 61730, and UL 1703. Of course,
there can be other variations, modifications, and alternatives for
these dimension numbers including the first dimension, second
dimension, the first thickness, and the peripheral region
dimension.
[0033] Additionally, as part of a light receiving top cover, the
concentrator referred in the FIG. 1 must possess a high
transmission and low reflection characteristics. In one embodiment,
the concentrator is made of glass having a transparent
characteristic with a transmissivity of 90 percent and greater for
a visible light range. This high transmissivity is achieved by
controlling the composition of the glass to reduce the sunlight
absorption to minimum. For example, the iron content of the glass
needs to be a trace amount and less. In another example, cerium
oxide with a concentration of about a trace amount or less or
non-existent. In another embodiment, there will be an
anti-reflective coating (not shown in FIG. 1) overlying the top
region 101 which is a flat surface. In yet another embodiment,
before applying the anti-reflective coating, an infrared blocking
coating (not shown in FIG. 1) may be applied overlying the top
region 101. This infrared blocking coating allows visible light
transmitted through but block the infrared spectrum so as to reduce
the heating to the photovoltaic region during the sunlight
conversion process. Of course, there can be other variations,
modifications, and alternatives.
[0034] FIG. 2 is a detailed diagram of a glass concentrator with a
plurality of elongated concentrating elements according to an
embodiment of the present invention. This diagram is merely an
example, which should not unduly limit the scope of the claims
herein. One of ordinary skill in the art would recognize other
variations, modifications, and alternatives. As shown is a local
cross-sectional view of the elongated concentrating elements
integrally formed with the back region of the webbing. Each of the
concentrating element includes at least the following geometric
elements: an aperture region 201, an exit region 203, a first side
region 207 provided between a first edge portion 211 of the
aperture region and a first edge portion 215 of the exit region, a
second side region 209 provided between a second edge portion 213
of the aperture region and a second edge portion 217 of the exit
region, and a second thickness 205 measured between the aperture
region 201 and the exit region 203. A second edge portion for a
first concentrating element 200a coincides with a first edge
portion of the neighboring second concentrating clement 200b to
form an aperture notch. For example, an aperture notch is located
at the edge portion 213. In one embodiment, because there is a
radius of curvature for each of the aperture notches (not shown in
FIG. 2), the true aperture region 201 is subtracted by a small
curved vicinity of two neighboring aperture notches at edge portion
211 and 213. Similarly, the exit notch also has a small radius of
curvature so that true light exit region should include those
curved exit notches. For example, exit region 203 should include
two exit notches at edge portion 215 and 217. The aperture region
201 is not an interface but an integral part of the back region 103
of the webbing 100.
[0035] For effectively collecting the sunlight, the concentrating
element is preferred to possess a geometric optical concentrating
characteristic. In a specific embodiment, the aperture region 201
is characterized by a light entrance area A2 and the exit region
203 is characterized by a light exit area A1. In an specific
embodiment, the light entrance area A2 includes only the true
aperture region excluding a small curved area of the aperture
notch. The light exit area A1 should include additional area
contributed by the curved exit notches. The light concentrating
characteristic is represented by an aperture-to-exit area ratio
A2/A1 ranging from about 1.8 to about 4.5. In one embodiment, the
aperture-to-exit area ratio is equivalent to a scale ratio as one
side of the aperture region 201 has a substantially equal dimension
of one side of the exit region 203. In other words, the exit region
203 has a reduced dimension compared to the aperture region 201 and
the two side regions 207 and 209 of the concentration elements are
tilt inward (relative to vertical direction). Sunlight coming
through the aperture region 201 with a relatively wide range of
incident angles will be completely reflected at the two side
regions because those incident angles (around the normal incident
angle) may still be larger than the total reflection angle of the
side region interface. In a specific embodiment, the second
thickness 205 is selected to be about 1.8 mm and the exit region
width is about 2 mm and the aperture region width is about 4.12 mm.
In one embodiment, each of the two side regions may be a flat type
of interface so that the cross-sectional view of the concentrating
element is a trapezoidal shape. In another embodiment, each of the
two side regions may be curved type of interface with variable
curvature values across the spatial of side regions. In yet another
embodiment, the curvature variations of the two side regions may be
symmetric. In yet still another embodiment, the curvature
variations of the two side regions may be non-symmetric. Of course,
there can be other variations, modifications, and alternatives.
[0036] In another specific embodiment, this light concentrating
characteristic is also represented by high reflectivity of the
inner face of the two side regions. Firstly, the high reflectivity
is achieved by polishing the glass at the two side regions so that
the roughness of the side region is reduced to a value of 30 nm RMS
and less. Secondly, certain thin film coating may be applied to
enhance the reflectivity. Of course, there can be other variations,
modifications, and alternatives.
[0037] In yet another specific embodiment, this light concentrating
characteristic is further implemented by certain roughening
treatment to the exit region to reduce the inner reflection at the
exit region to minimum. This treatment may allow most sunlight
beams reaching at the exit region be able to transmit through and
be received by a photovoltaic strip that may be attached below the
exit region in the solar concentrator modules. In one embodiment,
the photovoltaic strip can be attached to the exit region using an
optical adhesive. For example, the optical adhesive can be an
aliphatic polyurethane. in another embodiment, this optical
adhesive can be chosen to have an optical refractive index that
well matches with the glass concentrating element so that the
reflection loss at the interface of exit region would be minimized.
The refractive index of the glass concentrator is at least 1.4 or
greater. For example, the optical adhesive can be a two part
mixture using a aliphatic polyurethane mixture.
[0038] In yet still another specific embodiment, the light
concentrating characteristic also can be represented by other
geometric details such as micro-curvature near the vicinities of
the aperture notches 211 and 213 and exit notches 215 and 217. A
smaller radius of curvature for the aperture notch helps to
increase effective light entrance area. A smaller radius of
curvature for the exit region help to reduce the possible loss of
light collected from being directed away from the photovoltaic
strips. Certain embodiments of the present invention include a
method of making the glass concentrator with minimized notch radius
of curvature for each of the plurality of concentrating elements.
For example, the radius of curvature for the notches of the
concentrating element is about 0.1 mm or less. With a reduced notch
radius of curvature, the light concentrating efficiency is
improved. Of course, there can be other variations, modifications,
and alternatives. All these physical, mechanical, and optical
properties of the concentrating clement cumulatively contribute the
performance of the light concentrating function for manufacture of
an efficient and cost-effective solar conversion module according
to certain embodiments of the present invention.
[0039] Further detail of various methods according to embodiments
of the present invention on making the glass concentrator and
assembling a solar concentrator module are provided throughout the
present specification and more particularly below.
[0040] According to a specific embodiment, a method for making the
glass concentrator for manufacture of solar conversion module can
be outlined as follows:
1. Forming a ribbon glass in a floating bath with a rectangular
shape and a first thickness between a front surface and a back
surface; 2. Rolling with a shaped molding roller across the front
surface partially into the first thickness to form a plurality of
shaped structures; 3. Annealing the ribbon glass; 4. Rolling the
back surface while transporting the ribbon glass; 5. Polishing at
least partially each of the plurality of shaped structures.
[0041] These sequences of processes provide a way of performing a
method according to an embodiment of the present invention. As
shown, embodiments of the present invention provides a easy way of
integrally making the glass webbing with a plurality of elongated
concentrating elements possessing necessary light concentration
function while at the same time bearing other characteristics
required for an efficient solar energy conversion module that meets
all industrial qualification standards. The method can be
implemented based on established conventional floating glass
manufacturing technology. The flame polishing treatment also
provides a low cost high quality process for achieving the required
small roughness for certain portion of the concentrating elements.
Of course, there can be variations, modifications, and
alternatives. Some processes can be performed in different order.
Some processes can be removed or added. For example, when using
plastic material to replace glass, some process may be modified to
use direct molding to form the elongated concentrating elements.
Alternative polishing processes may also be utilized to achieve
required roughness and minimized notch radius. These and other
details of the present method can be found throughout the present
specification and more particularly below.
[0042] FIG. 3 is simplified diagram illustrating a method 300 of
making a glass concentrator according to an embodiment of the
present invention. This diagram is merely an example, which should
not unduly limit the scope of the claims herein. One of ordinary
skill in the art would recognize other variations, modifications,
and alternatives. As shown, the method 300 includes forming a
ribbon glass (process 311) in a floating bath with a rectangular
shape and a first thickness between a top surface and a back
surface. In one embodiment, a group of batch materials including
sand, limestone, cerium oxide, iron oxide and salt cake are
collected, then melted and blended in a furnace. In another
embodiment, the molten glass is made from polymer. The resulting
product is a molten glass with controlled compositions of certain
materials that bears the required physical characteristics
including photon absorption, mechanical strength, stress
distribution, or refractive index value etc. Of course, there can
be other variations, modifications, and alternatives.
[0043] Depending on the embodiment, the method 300 may include
feeding a predetermined amount of the molten glass or semi-fluid
polymer into a floating bath. The floating bath typically can be
made of tin with polished surface at its bottom and peripheral
sides having a desired rectangular dimensions and a depth. For
example, the rectangular dimensions are substantially the same as
the first dimension or the second dimension of the webbing
mentioned earlier in this specification. In a specific embodiment,
the floating bath is provided with a protective atmosphere
consisting of a mixture of nitrogen and hydrogen to prevent
oxidation of the tin. As being feed in the floating bath, the
molten glass spreads to entire bath spatially due to the gravity
and surface tension.
[0044] Depending on the embodiment, the method 300 may include
processing the ribbon glass to have a first thickness even for
entire ribbon glass between a top surface and a back surface. For
example the processing involves to control the temperature of the
floating glass so that it can spread to entire bath due to the
gravity and proper surface tension. In another example, the
processing includes rolling the top surface to speed up the
spreading or stretching of the floating glass. According to certain
embodiments, the first thickness is necessary for possessing
sufficient load sustenance and impact hail resistance
characteristics for the resulting glass webbing to be used for
manufacture of a solar concentrating module. For example, the first
thickness is at least 5 mm. In another example, the first thickness
is about 8 to 9 mm. The processing the ribbon glass also includes
annealing the ribbon glass and cooling it to a desired temperature
for a molding process.
[0045] Additionally, the method 300 includes rolling (process 321)
with a shaped molding roller across the front surface partially
into the first thickness to form a plurality of shaped structured
with a second thickness. The molding roller is at least longer than
one dimension of the ribbon glass in rectangular shape. The rolling
process may be performed after the formation of ribbon glass with
the even first thickness and the temperature of the subject ribbon
glass is cooled to a predetermined first temperature. Depending
upon the embodiment, the method may includes lowering a shaped
molding roller with a elongated body and a predefined
cross-sectional shape, aligning the roller in parallel with one
side of the rectangular-shaped ribbon glass, rolling the roller
across the top surface partially into the first thickness of the
ribbon glass, then re-lifting away from the top surface within a
first time period. In a specific embodiment, the lowering and
rolling of the molding roller is controlled to generate a second
thickness for the plurality of shaped structures during the rolling
process. In another specific embodiment, the rolling process
comprises a cooling procedure that uses a cooling system following
after the roller. The cooling system provides a localized cooling
for the just-formed structures on the top surface. For example, the
cooling system may spray a pulse of cold water or cryogenic
non-reactive gas locally. The localized cooling helps to partially
fix the shaped structures formed from the rolling process. In a
preferred embodiment, the plurality of shaped structures on the top
surface are a series of elongated elements substantially identical
to each other. Each of the elongated elements comprises an optical
concentrating geometry characterized by two side surfaces and a
scale ratio of an aperture region to an exit region larger than at
least 2.0. The plurality of shaped concentrating elements are
formed one-next-to-another with a second thickness on the top
surface of the ribbon glass. In another preferred embodiment, the
second thickness formed by the rolling process for each
concentrating element is about 1.8 mm. The remaining portion of the
ribbon glass belongs to the webbing.
[0046] Moreover, the method 300 includes annealing the ribbon glass
(process 331) to gradually cool the entire ribbon glass. Right
after a concentrating element is formed, a localized cooling is
applied for partially fix the shape of the concentrating element.
During that procedure, the temperature of the ribbon glass may be
cooled locally from the first temperature to a second temperature
via conduction and convention. After the rolling process, the
entire ribbon glass may be further annealed using another cooling
system. The annealing process is controlled to cool the ribbon
glass from the second temperature from a third temperature within a
second time period. Depending on the embodiment, the annealing
process helps to reduce the stress within the ribbon glass and
improve the load sustenance and impact resistance of the resulting
glass webbing.
[0047] As the ribbon glass is sufficiently cooled, the method 300
may include lifting the ribbon glass out of the floating bath and
transfer to a plurality of circular rollers coupling with the back
surface. The ribbon glass can be transported in the process 341
along the roller pathway to a polishing treatment stage. Then the
process 351 can be executed using an elongated burner that is
burning with hydrogen and oxygen gas mixture with a predetermined
mixing ratio. The elongated burner with a flame is directed to the
top surface containing the plurality of elongated concentrating
elements formed in the rolling process (321). The orientation of
the burner is substantially aligned with each of the plurality of
formed concentrating elements. Particularly, the burner is
configured to generate flames with a narrow, nearly one-dimensional
shape so that relatively small region of the concentrating element
can be treated with better control. For example, the formed
concentrating element is the elongated concentrating element 200
that has two side surfaces 207 and 209. The flame polishing
treatment is controlled to apply only on the side surfaces 207 and
209 but not on the exit region. In one embodiment, each side
surface is treated at a time while the burner is directed
sequentially from one side surface to another and from one
concentrating element to next. In another embodiment, the flame
treatment may also be used to adjust radius of the exit notches 215
and 217 etc. or reduce the radius of curvature of the aperture
notches 211 and 213 etc. In yet another embodiment, the flame
on/off, flame temperature, flame polish time, queue time, and other
process parameters can be controlled by a controller linked with a
computer so that the desired roughness of the two side regions or
desired exit radius can be achieved. For example, as low as 30 nm
RIMS and less for two side regions is preferred. Of course, there
can be many other variations, modifications, and alternatives.
[0048] The method 300 also includes rolling the back surface
(process 341) while annealing and transporting the ribbon glass.
Before and after the flame polishing process, the ribbon glass can
be rolled on its back surface by a plurality of rollers. The
rolling serves to flattening the back surface while transporting
the subject glass during which the glass continues to be annealed
to room temperature.
[0049] Although the method 300 has been specifically shown by those
process steps mentioned in above paragraphs, there can be many
other variations, modifications, and alternatives. Some of the
processes may be removed or be performed in different order. Other
processes may be added or used to replace some of above processes.
For example, the rolling process using a shaped molding roller for
forming the concentrating elements may be replaced by using a
shaped cast molding directed into the second thickness into the
ribbon glass with a first thickness. Alternatively, an etching
process may be used for forming the plurality of concentrating
elements. In another example, the flame polishing process may be
replaced by an acid polishing or a mechanical process. In yet
another example, plastic material can be used to replace glass for
the concentrator. Fixed molding can be used instead of roller and
other polishing techniques such as vapor polishing and mechanical
polishing may be used in addition to the flame polishing.
Additionally, one or more post-deposition processes may be
performed to overlay infrared blocking coating on the back surface
(which will become the front region for the solar module) when the
ribbon glass is transferred to a deposition chamber. Furthermore,
an anti-reflective coating may be deposited overlying the infrared
blocking coating. The side regions of the concentrating elements
can also be deposited with a reflectivity enhancement coating.
[0050] FIG. 4 is a simplified diagram illustrating a concentrating
element with an exit region in reduced width and two side regions
being flame polishing treated according to an embodiment of the
present invention. This diagram is merely an example, which should
not unduly limit the scope of the claims herein. One of ordinary
skill in the art would recognize other variations, modifications,
and alternatives. As shown, one elongated concentrating element 200
has a side region 207 and another side region 209. An elongated
burner 401 having substantially similar length as the concentrating
element 200 is aligned in substantially the same orientation. The
burner 401 is configured to have a plurality of gas nozzles (not
shown directly in FIG. 4). Hydrogen/oxygen gas mixture is supplied
though a build-in tubing in the burner holder. As ignited, the
plurality of gas nozzles is capable of generating a nearly
one-dimensional flame 403. In one embodiment, the gas mixing ratio
is predetermined to generate a desired heat transfer profile along
the axial direction of the flame. The burner 401 with the flame 403
is directed to the vicinity of the concentrating element 200 at a
predetermined variable distance. The flame 403 touches the side
region 207 to perform the polishing treatment. In another
embodiment, the burner 401 is configured to rotate in certain range
of angles 405 so that it can be guided to the one side region at a
proper angle at one time and then be guided with a proper angle to
the next side region at another time. In yet another embodiment,
the burner 401 can be laterally transported in direction 407 to
allow the polishing treatment being performed from one
concentrating element to another. In certain embodiments, multiple
burners that are similar to the burner 401 can be implemented at
the same time to speed up the treatment for all the concentrating
elements on the whole concentrator. Of course, depending upon the
embodiment, there can be many other variations, modifications, and
alternatives.
[0051] In an alternative embodiment, the invention provides a
method for assembling a solar concentrating module as illustrated
by FIG. 5. Preferably, the method can be implemented using the
glass concentrator made according to certain embodiments of the
present invention. A method 500 according to an embodiment of the
present invention can be outlined as follows:
1. Process 510: preparing a concentrator comprising a webbing with
a plurality of elongated concentrating elements having
light-collecting exit regions; 2. Process 520: providing an optical
coupling material overlaying the light-collecting exit regions; 3.
Process 530: providing a plurality of photovoltaic strips; 4.
Process 540: bonding the plurality of photovoltaic strips using at
least the optical coupling material to the light-collecting exit
regions; 5. Process 550: providing a back cover member, wherein the
back cover member can be rigid or flexible; 6. Process 560:
clamping the back cover member with. the webbing; 7. Process 570:
performing other steps, as desired.
[0052] These sequences of processes provide a way of performing a
method according to an embodiment of the present invention. As can
be seen, the method provides a technique for assembling a solar
concentrator module using the concentrator made according to
another embodiment of the invention. Of course, there can be
variations, modifications, and alternatives. Some processes can be
performed in different order. Some processes can be removed or
added. For example, clamping a rigid back member with the planar
webbing of the glass concentrator is performed differently from
clamping a flexible backsheet with the webbing. After the clamping
the back cover member with the webbing, a sealing process may be
performed. In another example, the clamped package comprising
hollow space between the photovoltaic strips and the back cover
member will not be sealed, instead, air or other vapor is allowed
to breath in/out. Further details of the present method and
resulting structures can be found throughout the present
specification and more particularly below.
[0053] Referring now to FIG. 6, an expanded view of a solar
concentrator module assembly according to an embodiment of the
present invention is illustrated. This diagram is merely an
example, which should not unduly limit the scope of the claims
herein. One of ordinary skill in the art would recognize other
variations, modifications, and alternatives. As shown in FIG. 6, a
solar concentrator module includes various elements. The module has
a glass concentrator 610, which is a planar webbing including a
front region, a back. region, a shape characterized by a first
dimension and a second dimension, and a first thickness provided
between the front region and the back region. The front region is a
flat surface which is also a top surface of the module for
receiving the sunlight. The back. region integrally includes a
plurality of elongated concentrating elements. Each of the
elongated concentrating elements includes a light-collecting exit
region. For example, the glass concentrator 610 is a planar webbing
glass with shaped concentrating elements made from the method of
300 referred in FIG. 3. In one example, the planar webbing has a
planar region comprising a rectangular shaped panel with the first
dimension about 1 meter or bigger and a second dimension about 1.6
meter or bigger. As an example, for assembling a solar concentrator
module, the glass concentrator 610 may be prepared by the process
510.
[0054] In a preferred embodiment, the plurality of elongated
concentrating elements is characterized by a geometric optical
concentrating function. In one embodiment, the concentrating
function is represented by an elongated exit region with a reduced
dimension versus a light entrance area corresponding to each
concentrating element. Each of the elongated concentrating elements
joins with one or two neighboring element to form an aperture
notch. An aperture notch with minimized radius of curvature helps
to maximize the true size of aperture region, i.e., the light
entrance area. In another embodiment, the concentrating function is
represented by the two highly reflective side regions for each of
the elongated concentrating element that help to direct light
coming in the aperture region to the exit region with minimum loss.
In another preferred embodiment, the exit region is a second
distance away from the back region of the planar webbing. The
plurality of elongated concentrating elements cumulatively occupies
the entire back region except a peripheral region surrounding the
planar webbing.
[0055] An optical coupling material 620 is provided overlaying the
spatial area of the exit region for each and every elongated
concentrating elements. The optical coupling material will be used
for bonding the concentrating element with the solar energy
conversion unit. For example, the optical coupling material is
aliphatic polyurethane. In a preferred embodiment, the optical
coupling material has a refractive index of about 1.4 or greater
that is well matched with the glass concentrator used for this
assembly. The matching of the refractive index will ensure minimum
loss of the collected light beam from being reflected from the
interface between the exit region and the coupling material.
Additionally, the coupling material is desired to have a suitable
Young's Modulus and a thermal expansion coefficient so that the
coupling material can withstand for changes due to thermal
expansion of both the glass element and photovoltaic strip element.
For example, the optical coupling material is a aliphatic
polyurethane, but can be others. As an example, the optical
coupling material 620 is provided in process 520.
[0056] Referring to FIG. 6 again, the solar concentrator module
further includes a plurality of photovoltaic strips 630. These
photovoltaic strips are formed on a semiconductor substrate and are
cut into a strip shape defined by two short sides with a strip
width and two long edges with a strip length. In one embodiment,
the strip width is about 2 mm which is substantially the same as a
preferred width of the exit region. The strip length is about 6
inches. Each of the photovoltaic strips includes a plurality of
p-type regions and a plurality of n-type regions. Each of the
p-type regions is coupled to at least one of the n-type regions to
form a p-n junction unit capable of converting photo energy to
electricity. For example, the photovoltaic strips are made of at
least one material selected from single crystal silicon,
polycrystalline silicon, amorphous silicon, copper indium
diselenide (CIS), Copper Indium Gallium Selenide (CIGS), Cadmium
Telluride (CdTe), thin film materials, or nanostructured materials.
Of course, there can be other variations, modifications, and
alternatives. As an example, the plurality of photovoltaic strips
is provided in process 530.
[0057] As an example, the solar concentrating module includes a
plurality of photovoltaic strips spatially disposed in a parallel
manner overlaying the exit regions of the elongated concentrating
elements. Each of the photovoltaic strips is operably bounded with
at least a portion of one exit region by the optical coupling
material 620. In one embodiment, the length of an exit region of
the concentrating element is about 1 meter or bigger. Multiple
photovoltaic strips are required to attach with the exit region one
following another and cumulatively covers all spatial area of the
exit region. Similarly, a plurality of photovoltaic strips are
attached with each and every exit region of the plurality of
concentrating elements. Of course, there can be other variations,
modifications, and alternatives. As an example, the plurality of
photovoltaic strips are bounded with corresponding concentrating
elements in process 540.
[0058] In a preferred embodiment, each of the photovoltaic strips
comprises a plurality of electric leads located on two long edges.
Each of the plurality of electric leads is coupled to each other
through thin conductive wires. Additionally, conductive means
including but not limiting bus bars are used for coupling the
neighboring photovoltaic strips. These electric leads and
conductive means are configured to link to an electric circuit for
providing electric power that is generated from the sunlight by p-n
junction units in the plurality of photovoltaic strips. Of course,
there can be other variations, modifications, and alternatives.
[0059] Further referring to FIG. 6, the solar concentrator module
also includes a rigid back cover member 640. The back cover member
includes a planar region comprising a electric circuit board and a
peripheral uprising edge wall. The electric circuit board is
configured for coupling with the plurality of electric leads on
each of the plurality of photovoltaic strips and providing power
management for module electric power output. The edge wall of the
back cover member is configured to be easily clamped with the
webbing of the concentrator at the peripheral region. The edge wall
has a properly selected height that is substantially suit for
enclosing the entire rest parts of the module including the glass
concentrator, the photovoltaic strips, circuit board and all
coupling materials in between. In one embodiment, the back cover
member 640 is characterized by an anodized aluminum bearing
material. In another embodiment, the back cover member 640 is made
of plastic material. In yet another embodiment, the back cover
member has a surface feature configured to provide efficient heat
dissipation. For example, a plurality of fins may be formed on the
outer surface of the back cover member. Of course, there can be
other variations, modifications, and alternatives on the material
selection and mechanical design for the back cover member. For
example, the back cover member 640 is provided in process 550.
[0060] In a preferred embodiment, the back cover member 640 is
clamped with the glass webbing of the concentrator 610. The glass
webbing of the concentrator 610 has an about 10 mm peripheral
region being left out without the concentrating elements and
intentionally designed for the module packaging purpose. In one
embodiment, the clamping can be done based on mechanical mechanism
using clips or screws etc. In another embodiment, the clamping is
performed by welding the back cover member and an encapsulating
frame of the glass together. The edge wall of the back cover member
is specifically designed to match with the peripheral region of the
glass webbing. In another embodiment, the clamping between the back
cover member and the rest of module is done by a glue-bonding
mechanism. Depending on the embodiment, the resulting solar module
from any clamping mechanism contributes effectively to many
characteristics related to load sustenance, impact resistance, and
ability to withstand environmental stress or aging. Of course,
there can be other variations, modifications, and alternatives. As
an example, the clamping of the back cover member 640 to the
webbing is performed at process 560. Of course, there can be other
variations, modifications, and alternatives.
[0061] In an alternative embodiment, the uprising surrounding wall
of the back cover member has a height more than that required for
enclosing all the rest components of the solar concentrator module
so that there are some spatial region between the photovoltaic
strips and the back cover member. In one embodiment, after the
clamping process, a sealing process may be performed to add
vacuum-tight encapsulate material around the clamping joint. The
sealing encapsulate material is selected based on module
qualification test requirement imposed for the solar module. The
qualification tests include damp heat test, humidity freeze test,
thermal cycling test, UV or hot-spot tests or other aging tests.
The vacuum sealed packaging may have advantage to perform better to
reduce certain types of damage related to moisture dropped onto the
photovoltaic strips. In another embodiment, the clamped package is
intentionally left some micro passage ways to allow breathing,
i.e., during day time the heated spatial region between the
photovoltaic strips and the back cover member can drive out the
absorbed moisture inside the module. Of course, there can be other
variations, modifications, and alternatives.
[0062] In an alternative embodiment, referring to FIG. 7, the solar
concentrator module includes all components mentioned earlier
except that the rigid back cover member can be replaced by a
flexible backsheet 640'. FIG. 7 is just an exemplary illustrating
of such solar concentrator module including the flexible backsheet.
The flexible backsheet is configured to adapt the surface
corrugation after attaching the plurality of photovoltaic strips to
the concentrator elements. Additionally, the flexible backsheet,
according to certain embodiments of the invention, still is capable
of providing the necessary mechanical support and environmental
protection for the solar concentrator module. In one embodiment,
the flexible backsheet 640' is also provided in process 550 and is
clamped with the glass concentrator 610 in process 560.
[0063] It is also understood that the examples and embodiments
described herein are for illustrative purposes only and that
various modifications or changes in light thereof will be suggested
to persons skilled in the art and are to be included within the
spirit and purview of this application and scope of the appended
claims.
* * * * *