U.S. patent application number 11/707461 was filed with the patent office on 2007-08-30 for apparatus for concentration and conversion of solar energy.
Invention is credited to Martin D. Fox.
Application Number | 20070199563 11/707461 |
Document ID | / |
Family ID | 38442844 |
Filed Date | 2007-08-30 |
United States Patent
Application |
20070199563 |
Kind Code |
A1 |
Fox; Martin D. |
August 30, 2007 |
Apparatus for concentration and conversion of solar energy
Abstract
The present invention is directed to an apparatus for the
collection and conversion of light energy including a collector
element defining the shape of a pentagon, and a concentrator
including a plurality of pentagon shaped reflector elements
symmetrically arranged around the collector element. Each of the
reflector elements being disposed at an angle relative to a plane
of the collector element and having an edge thereof substantially
aligned with and adjacent one of the sides of the collector
element.
Inventors: |
Fox; Martin D.; (Storrs,
CT) |
Correspondence
Address: |
MCCORMICK, PAULDING & HUBER LLP
CITY PLACE II
185 ASYLUM STREET
HARTFORD
CT
06103
US
|
Family ID: |
38442844 |
Appl. No.: |
11/707461 |
Filed: |
February 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60774237 |
Feb 16, 2006 |
|
|
|
Current U.S.
Class: |
126/684 |
Current CPC
Class: |
F24S 2030/16 20180501;
F24S 20/55 20180501; F24S 23/77 20180501; Y02B 10/20 20130101; Y02E
10/40 20130101; H01L 31/0547 20141201; Y02E 10/52 20130101; F24S
30/40 20180501 |
Class at
Publication: |
126/684 |
International
Class: |
F24J 2/10 20060101
F24J002/10; F24J 2/08 20060101 F24J002/08 |
Claims
1. An apparatus for the collection and conversion of light energy
comprising: a collector element defining the shape of a pentagon,
and a concentrator including a plurality of pentagon shaped
reflector elements symmetrically arranged around the collector
element, each of the reflector elements disposed at an angle
relative to a plane of the collector element and having an edge
thereof substantially aligned with and adjacent one of the sides of
the collector element.
2. The apparatus of claim 1 wherein the reflective elements are
positioned at about a 60 degree angle relative to the plane of the
collection element.
3. The apparatus of claim 1 wherein the reflective elements are
positioned relative to the collection element at angles
corresponding to those in a dodecahedron Platonic solid.
4. The apparatus of claim 1 wherein each of the reflective elements
are positioned relative to the collection element an angle thereto
to uniformly distribute the reflected light across a surface of the
collector element.
5. The apparatus of claim 1 wherein each of the shape of at least
one of the reflective elements defines a regular pentagon.
6. The apparatus of claim 1 wherein the geometry of at least one of
the reflective elements is that of an irregular pentagon.
7. The apparatus of claim 1 wherein the reflective elements
comprise one or more regular pentagons and one or more irregular
pentagons.
8. The apparatus of claim 1 wherein the reflective elements are
connected to the collection element by a connection mode selected
from the group comprising: fixed, adjustable, hinged, rotatable,
and remotely controllable.
9. The apparatus of claim 1 further comprising a means of tracking
the position of a source of incident light and adjusting the
position of the apparatus with respect thereto so as to optimize
the collection of light energy.
10. The apparatus of claim 1 wherein the reflective elements are
selected from the group comprising mirrors, reflective plastic
materials, reflective metal materials and elements enclosing
reflective particles suspended in a fluid, gel or solid medium.
11. The apparatus of claim 1 wherein the collection element is
selected from the group comprising photovoltaic cells, photovoltaic
panels, coiled tubing containing a heatable fluid, light pipe,
solar oven, water heater, hot water-powered turbine, and devices
suitable for recharging batteries.
12. The apparatus of claim 1 wherein the pentagonal reflective
elements abut the adjoining such elements along most or all of
their respective abutting edges.
13. The apparatus of claim 1 wherein the reflective elements are
positioned relative to the plane of the collection element at an
angle between about 50 degrees and about 72 degrees.
14. The apparatus of claim 1 wherein the reflective elements are
positioned relative to the plane of the collection element at an
angle between about 58 degrees and about 62 degrees.
15. The apparatus of claim 1 wherein the reflective elements are
positioned relative to the collection element at any angle that
provides at least 2 suns of light concentration on the collector
element.
16. An apparatus for the collection and conversion of solar energy
comprising a plurality of pentagon-shaped reflective elements
symmetrically arranged around a pentagon-shaped collector
element.
17. The apparatus of claim 16 wherein at least one of the
reflective elements defines the geometry of a regular pentagon.
18. The apparatus of claim 16 wherein at least one of the
reflective elements defines the geometry of an irregular pentagon
and wherein the collection element defines the geometry of a
regular pentagon.
19. The apparatus of claim 1 wherein the reflective elements may be
folded up for convenience, portability and to protect said elements
and the collection element from damage, moisture environmental
exposure.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application No. 60/774,237 filed on Feb. 16, 2006 and titled
"Apparatus for Concentration and Conversion of Solar Energy". The
disclosure of the provisional application is incorporated in its
entirety herein by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains generally to apparatus for
the collection and conversion of solar energy to other types of
useful energy. More particularly the invention is directed to an
apparatus for the collection and conversion of light energy having
a plurality of pentagonal reflector elements arranged about a
pentagonal shaped collector element.
BACKGROUND OF THE INVENTION
[0003] Solar concentrators collect sunlight over an area and direct
the light onto a collection or conversion element such as a
photovoltaic element. Typically, the collection or conversion
element defines a smaller surface area than that of the
concentrator. In this way, the radiant energy incident on the
entire area of the concentrator is directed to the collection or
conversion element and converted to useful energy such as
electrical power where the concentrator is coupled to a
photovoltaic element.
[0004] Current solar collectors and conversions systems include a
wide range of devices including the use of lenses and reflectors
which are often very sensitive to the angle of incidence of the
sunlight. Other devices employ tracking systems to track the sun's
movement and thereby attempt to optimize the position of a solar
collector relative to the angle of the sunlight.
[0005] Representative examples of prior art devices for the
collection and conversion of solar energy include:
[0006] U.S. Pat. No. 6,700,055 to Barone discloses a solar
concentrator system including a collector lens for collecting and
at least partially focusing incident solar rays, a solar cell and a
lens array positioned generally between the collector lens and the
solar cell, the lens array directing the partially focused rays
emerging from the collector lens onto the solar cell.
[0007] U.S. Pat. No. 6,700,054 to Cherney et al. which discloses a
solar collection system and method having means for receiving solar
radiation through a main refractive interface and means for
internally reflecting at least once a portion of the solar
radiation. The refractive medium may be liquid, gel or solid. The
device can be integrated with a photovoltaic device, a
photohydrolytic device, a heat engine, a light pipe or a
photothermal receptor.
[0008] U.S. Pat. No. 6,840,645 discloses a light tube system for
distributing sunlight or artificial light. One embodiment of the
system includes a pair of opposed reflectors rotatably mounted to
track the movement of the sun.
[0009] U.S. Pat. No. 6,061,181 is directed to a nontracking light
converger including a housing surrounding a light absorbing means
such as a heat conductive conduit or a photovoltaic cell collector
plate. Angularly extending from the upper surface of the light
absorbing means are a plurality of substantially triangular prisms
for refracting and directing light from the open top of the housing
downwardly towards the light absorbing means.
[0010] One disadvantage of many prior art devices is that they
require one of more lenses for focusing the sunlight onto a solar
cell or other device which can be an expensive components and
significantly add to the cost of the energy generated.
[0011] Another disadvantage of many prior art systems is the
requirement of a tracking system which also significantly adds to
the cost of the energy.
[0012] Based on the foregoing, it is the general object of the
present invention to provide an apparatus for the concentration and
conversion of solar energy that overcomes many of the problems and
drawbacks of prior art systems.
SUMMARY OF THE INVENTION
[0013] The present invention provides an apparatus for the
collection and conversion of light energy including a collector
element defining the shape of a pentagon, and a concentrator
including a plurality of pentagon shaped reflector elements
symmetrically arranged around the collector element. Each of the
reflector elements disposed at an angle relative to a plane of the
collector element and having an edge thereof substantially aligned
with and adjacent one of the sides of the collector element.
[0014] In one embodiment, the concentrator includes five reflector
elements each defining the shape of a regular pentagon, a regular
pentagon having five sides of equal length. The apparatus of the
present invention including reflector elements shaped as regular
pentagons provides an increased concentration of 2.5 times the suns
radiation on the collector element or "2.5 suns".
[0015] In other embodiments of the present invention irregular
pentagons are utilized to provide further enhanced concentration of
light incident on the collector element.
[0016] One object of the present invention is to provide an
apparatus for solar concentration on a collector element ranging
from about 3 times to about 6 times the incident radiation of the
sun.
[0017] Another object of the present invention is to provide a cost
effective solar collection and conversion device including only
readily available reflective materials, such as flat mirrors
configured according to novel geometries so as to produce enhanced
solar concentration.
[0018] Another object of the present invention is to provide an
apparatus for solar collection and conversion which is small and
lightweight and useful for various applications such as recharging
batteries for electronic devices such as cellular telephones,
computers, personal digital assistants (PDAs), and other similar
devices.
[0019] Another object of the present invention is to provide
large-scale apparatus for solar collection and conversion for
mounting on buildings, vehicles, or in remote locations having
limited access to electrical power.
[0020] Another object of the present invention is to provide an
apparatus for solar collection and conversion wherein the energy
produced by the apparatus allows for recouping the cost of the
apparatus within a range of about two to about four years.
[0021] A further object of the present invention is to provide an
apparatus for solar collection and conversion that includes
embodiments that are affordable and cost-effective for industrial,
municipal, residential and personal applications.
[0022] These and other objects, features and advantages of the
present invention will become more apparent in view of the
following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view of one embodiment of an
apparatus for the collection and conversion of light energy
according to the present invention.
[0024] FIG. 2 is an illustration showing an example of the
reflection of solar rays incident on the reflective elements of the
present invention.
[0025] FIG. 3 is an illustration comparing the geometry of two
different pentagons useful in various embodiments of the
concentrator of the present invention.
[0026] FIG. 4 is an illustration showing the geometry of the
irregular shaped pentagon of FIG. 2 in accordance with one
embodiment of the concentrator of the present invention wherein the
reflectors abut an adjacent reflector throughout substantially the
entire length of the adjoining sides therebetween.
[0027] FIG. 5 is an illustration showing the geometry of another
pentagon used in accordance with another embodiment of the
concentrator of the present invention.
[0028] FIG. 6 is a perspective view of one embodiment of a light
pipe in accordance with the present invention.
[0029] FIG. 7 is a perspective view of one embodiment of a thermal
oven in accordance with the present invention.
[0030] FIG. 8 is a perspective view of one embodiment of a
photovoltaic electrical power generator in accordance with the
present invention.
[0031] FIG. 9 is a perspective view of a solar water heater
according to the present invention.
[0032] FIG. 10 is an illustration of a solar tracking photovoltaic
electrical power generator according to the present invention.
[0033] FIG. 11 shows a plurality of the apparatus of the present
invention shown mounted on a flat surface collectively forming a
collector array.
[0034] FIGS. 12A and 12B are perspective views of one embodiment of
the apparatus of the present invention which is collapsible.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0035] Referring to FIG. 1, one embodiment of an apparatus for the
collection and conversion of light energy in accordance with the
present invention is generally referred to by the reference number
10. The apparatus 10 includes a collector or conversion element
hereinafter referred to generally as a "collector element" and
identified by the reference numeral 12. A concentrator 13 includes
a plurality of reflector elements 14 arranged about the perimeter
of the collector element 12 and disposed at an angle .THETA.
relative to a plane P defined by the collector element 12 and the X
and Y axes shown in FIG. 1.
[0036] In a preferred embodiment of the present invention, as shown
in FIG. 1, the collector element 12 includes a collector surface 15
which defines a regular pentagon, i.e. a pentagon having five sides
of equal length. The collector element 12 includes a plurality of
photovoltaic solar cells 16 arranged throughout the collector
surface 15 for converting the radiant energy incident on the solar
cells to electrical power. Typically, the solar cells 16 utilize
crystalline silicon or gallium-arsenide or other materials which
are known in the art.
[0037] A plurality of reflector elements 14 are arranged
symmetrically around the perimeter of the collector element 12. In
the FIG. 1 embodiment, the reflector elements 14 each define a
regular pentagon 17 wherein a lower edge 18 of each of the regular
pentagons is arranged to abut an edge 20 of the collector surface
which is adjacent thereto. In the FIG. 1 embodiment, the reflector
elements 14 are each disposed at angle .THETA. equal to sixty
degrees from the collector surface 15 resulting in each of the
regular pentagons 17 having a side edge 22 being spaced apart from
the side edge 22 of an adjacent regular pentagon at an angle of
approximately 4 degrees (the spacing being identified by the
reference number 24 in FIG. 1).
[0038] FIG. 2 illustrates the reflection R of a light ray I
incident on one of the reflector elements 14 of the apparatus 10.
The incoming light ray I is reflected from the reflector element 14
and is incident on the collector surface 15 at an opposite edge
thereof. Although not shown, intermediate light rays incident on
the reflector element 14 are equally distributed to the collector
element 12 throughout the collector surface 15.
[0039] In the FIG. 1 embodiment, there is a five to one ratio
between the area of the collector surface 15 and the total working
area of the five reflector elements 14 thereby increasing the
effective area of the collector surface 15. The light gathering
ability of the apparatus 10 is defined generally by the additional
effective area of the collector element 12. In the FIG. 1
embodiment, each of the reflector elements 14 provide illumination
equal to approximately 50% the light energy incident on the
collector surface 15 directly. Thus, with five reflector elements
14 the available solar photonic radiation incident on the collector
surface 15 is increased by a factor of 2.5. Accordingly, the
increased light energy of 2.5 times that incident directly on the
collector surface 15, plus the 1 times the light which is incident
directly on the collector surface equals a total of 3.5 times the
suns radiation on the collector surface or 3.5 "suns". Thus, the
FIG. 1 embodiment of the apparatus 10 according to the present
invention including five reflector elements 14 which each define a
regular pentagon 17 provides a total collection power of
approximately 3.5 suns.
[0040] In other embodiments of the present invention, the apparatus
10 is constructed using reflector elements 14 which define
irregular pentagons. Two examples are identified following
including a discussion of the advantages of the different
arrangements.
[0041] Referring to FIGS. 3 and 4, an irregular pentagon 30 is
provided for the reflector elements 14 of the present invention
that provides uniform illumination of the collector surface 15 and
forms a "closed geometry" concentrator 13 of the apparatus 10 such
that the reflector elements 14 adjacent to one another abut along
substantially the entire length of the side edges 22 thereof. (See
FIG. 11). This closed geometry of the irregular pentagon 30
provides for the maximum mechanical strength of the concentrator 13
wherein a plurality of the reflector elements are coupled together
adjacent one another along the edges 22 thereof. Additionally, the
pentagon 30 provides for efficient usage of the material of the
reflector elements 14 as there should be no waste between the side
edges 22 thereof when multiple reflector elements are formed from a
single sheet of material. The reflector elements 14 can be attached
one to the other and to the collector element 15 using various
methods including adhesives, clamps, brackets or similar
devices.
[0042] The above-identified characteristics of pentagon 30 are
achieved by reducing the elevation angle .THETA. from 60 degree of
the regular pentagon 17 of FIG. 1, to 58.2824 degree, increasing
the base internal angles B to 110.905 degree, and a linear
compression of 0.85064 (thereby reducing the height h) of the
pentagon. The apparatus 10 having a plurality of reflector elements
14 corresponding to the shape of pentagon 30 provides a dosed
geometry for the concentrator 13 yielding a solar concentration of
3.24 suns.
[0043] The geometry of pentagon 30 is particularly effective for a
concentrator 13 formed from a unitary embossed reflective plate
with single crystal photovoltaic elements in a well thereof which
provides the collector element 12. Also due to the more open
geometry resulting from the lower angle of elevation .THETA., the
pentagon 30 design provides improved efficiency than the regular
pentagon for use in stationary non-tracking systems.
[0044] Referring again to FIG. 1, in another embodiment, the
concentrator 13 is formed using the regular pentagons 17 in a
closed geometry configuration by including a non-reflective
gap-filler material to close the gaps 24 between the reflector
elements 14. Typically, a non-reflective material can be used to
black out the reflector portion of a mirror in the areas 24, or the
regular pentagon shaped reflector is mounted to a base plate shaped
as the regular pentagon 17 with a border to include the areas 24.
Accordingly, the apparatus 10 includes a concentrator 13 having a
closed geometry structure with the reflector elements 14 defined by
regular pentagons 17.
[0045] Referring to FIG. 5, another embodiment of the apparatus 10
provides a closed geometry concentrator 13 having a plurality of
reflector elements 14 each defining an irregular pentagon 40 based
on a dodecahedron which defines an elevation angle .THETA. equal to
63.4 degree relative to the collector element 12. Thus, in a
dodecahedral embodiment, the concentrator 13 includes five
pentagons 40 arranged at an elevation angle .THETA. equal to 63.4
degree relative to the collector element 12. As shown in FIG. 5,
the pentagon 40 includes base internal angles B equal to 108
degree, and a linear extension of 1.34164, thereby increasing the
height h of a regular pentagon 17. The pentagon 42 represents the
active reflecting portion of the reflector element 14 for
maintaining uniform illumination of the collector element 12 at the
elevation angle .THETA. equal to 63.4 degree. The concentrator 13
having a plurality of reflector elements 14 corresponding to the
shape of pentagon 40 provides a closed geometry for the
concentrator 13 yielding a solar concentration of 4.0 suns which is
a 14% increase over the concentrator 13 formed from the regular
pentagons 17.
[0046] In general, when the elevation angle .THETA. of the
reflector elements 14 is increased, the half angles between the sun
and the normal to the reflector elements are also increased and the
outer reflected rays are pulled inward. Increasing the height of
the pentagon allows the outer rays to be reflected so as to contact
the collector element 12 at an opposing edge thereof thereby
providing an increase in the light energy incident on the collector
element 12 when compared with a concentrator 13 formed of regular
pentagons 17.
[0047] Referring again to FIG. 5, in the dodecahedral embodiment,
the concentrator 13 provides a dosed geometry structure as defined
by five of the pentagons 40; however, to maintain uniform
illumination on the collector element 12, the reflective element
utilized is restricted to the pentagon 44. The areas 46 shown
between the pentagons are blacked out or left open such that there
is no reflective surface in these areas. Thus, in the dodecahedral
embodiment, even though the black out areas 46 are required, the
concentrator 13 provides a closed geometry structure yielding a 4
sun concentration incident on output of the collector element.
[0048] In other embodiments of the present invention, the
concentrator 13 can provide still further increases in
concentration levels; e.g., at an elevation angle .THETA. of 67
degree, the concentrator will provide a concentration of
approximately 4.5 sun; at an elevation angle .THETA. of 71 degree,
the concentrator will provide a concentration of approximately 5
sun; at further increased elevation angles, a maximum concentration
level of 6 sun is achievable. However, concentrators 13 providing
these higher concentrations require larger reflector elements 14
which can be impractical for some applications due in part to the
cost of the reflectors utilized.
[0049] Referring to FIG. 6, in another embodiment of the present
invention, the apparatus 10 includes a concentrator 13 coupled to a
collector element 12 including a light pipe 46.
[0050] In the FIG. 7 embodiment, the apparatus 10 includes a
concentrator 13 coupled to a collector element 12 including a
thermal oven 48 or other type of photothermal receptor.
[0051] Referring to FIG. 8, another embodiment of the apparatus 10
includes a collector element 12 including a photovoltaic array 50
coupled to a solar controller 52.
[0052] Referring to FIG. 9, another embodiment of the apparatus 10
includes a collector element 12 having a tubing array 54 for
carrying a liquid or gel for transferring concentrated radiant
energy from the concentrator 13 thereto.
[0053] Referring to FIG. 10, the apparatus 10 in accordance with
the present invention includes a tracking mechanism 56 and
controller 58 therefor, for tracking the movement of the sun and
focusing the collector element 12 towards the sun for further
increasing the incidence of sunlight on the collector element. The
tracking mechanism 56 provides a means of tracking the position of
a source of incident light and adjusting the position of the
apparatus 10 with respect thereto so as to optimize the collection
of light energy.
[0054] Referring to FIG. 11, in another embodiment of the present
invention, a plurality of the apparatus 10 are arranged adjacent
one another attached to a surface 60 collectively forming a
collector array 62.
[0055] Referring to FIGS. 12A and 12B, one embodiment of the
apparatus 10 of the present invention includes a concentrator 13
which is collapsible wherein each of the reflective elements 14 is
pivotably coupled to the collector element 12 and movable between
open and dosed positions. When the reflector elements 14 are in the
open position, shown in FIG. 12A, the collector element 12 is
exposed and the apparatus 10 is operational. In the closed
position, shown in FIG. 12B, the concentrator 13 includes each of
the reflector elements 14 folded over one another such that the
reflective portions thereof and the collector element 12 are
protected from the weather. The reflector elements 14 may be folded
up for convenience, storage, portability and/or to protect the
reflector elements and the collection element from damage, moisture
and environmental exposure.
[0056] In the FIGS. 12A and 12B embodiment, the concentrator 13
includes reflector elements 14 defining regular pentagons 17 such
that the concentrator defines an open structure having a gap
between the side edges 22 of the adjacent reflector elements as set
forth above. This open geometry of the concentrator 13 facilitates
the pivotable arrangement of the reflector elements 14 required for
the collapsible and/or portable design of the FIG. 12 embodiment of
the apparatus 10.
[0057] In other embodiments of the apparatus 10, the reflective
elements are connected to the collection element 12 by a connector
such as a fixed, adjustable, hinged, rotatable, and remotely
controllable connector.
[0058] In various embodiments of the present invention, the
reflector elements 14 are manufactured from materials including
mirrors, reflective plastic materials, reflective metal materials
and elements enclosing reflective particles suspended in a fluid,
gel or solid medium.
[0059] The collection element 12 can include photovoltaic cells,
photovoltaic panels, coiled tubing containing a heatable fluid, a
light pipe, a solar oven, a water heater, a hot water-powered
turbine, and devices suitable for recharging batteries as well as
other types of energy conversion devices.
[0060] Accordingly, the present invention apparatus for the
collection and conversion of light energy 10 provides an efficient
method to collect and concentrate light and other forms of
radiation including sunlight, moonlight, lightning, artificial
light, reflected light, refracted light and UV radiation.
[0061] The foregoing description of embodiments of the invention
have been presented for the purpose of illustration and
description, it is not intended to be exhaustive or to limit the
invention to the form disclosed. Obvious modifications and
variations are possible in light of the above disdosure. The
embodiments described were chosen to best illustrate the principals
of the invention and practical applications thereof to enable one
of ordinary skill in the art to utilize the invention in various
embodiments and with various modifications as suited to the
particular use contemplated. It is intended that the scope of the
invention be defined by the claims appended hereto.
* * * * *