WO2013115796A1

WO2013115796A1 - Photovoltaic energy apparatuses and methods

Info

Publication number: WO2013115796A1
Application number: PCT/US2012/023341
Authority: WO
Inventors: Stephan Clark; Frank Bretl
Original assignee: Hewlett Packard Development Co LP
Current assignee: Hewlett Packard Development Co LP
Priority date: 2012-01-31
Filing date: 2012-01-31
Publication date: 2013-08-08
Anticipated expiration: 2014-07-31

Description

PHOTOVOLTAIC E ERGY APPARATUSES AND METHODS

STATEMENT OF GOVERNMENT INTEREST

[0001] The invention that is the subject of this patent application was made with Government support under Subcontract No. CW135971 , under Prime Contract No. HR001 1 -07-9-0005, through the Defense Advanced Research Projects Agency (DARPA). The Government has certain rights in this invention.

BACKGROUND

[0002] Photovoltaic cells generate electrical energy by way of direct conversion of solar or other photonic radiation. Improvements in system component effectiveness, thermal characteristics and reduced manufacturing cost are constantly sought after. The present teachings address the foregoing and related concerns.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The present embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

[0004] FIG. 1 is a schematic view of a system according to an example of the present teachings;

[0005] FIG. 2 depicts an isometric-like view of a panel assemblage according to another example; [0006] FIG. 3 depicts an isometric-like view of an apparatus including a panel;

[0007] FIG. 4 depicts an isometric-like view of details of an apparatus including a panel;

[0008] FIG. 5 depicts a section view of a panel;

[0009] FIG. 6 depicts a flow diagram of a method according to the present teachings

DETAILED DESCRIPTION

INTRODUCTION

[0010] Apparatus and methods related to solar energy are provided. A framework formed from metal side and end portions is assembled and used to support a reflector there within. A cover and a transparent window to are also added to generally enclose and protect the reflector. PV cells are supported within the framework such that a panel is defined. The PV cells are located so as to receive concentrated photonic energy from the reflector and to generate or derive electrical energy.

[0011 ] Heat pipes can be disposed within a channel about the framework.

The heat pipes function to distribute heat not used by the PV cells along the framework, thus increasing the heat dissipation effectiveness of the panel overall. The panel can be angularly positioned by way of a sun tracking apparatus. Solar energy systems of any practical scale can be defined and used accordingly.

[0012] In one example, an apparatus includes a framework having a channel about the periphery thereof. The apparatus also includes a reflector joined to the framework. The reflector is configured to concentrate photonic energy onto one or more target areas. The apparatus also includes one or more photovoltaic cells in thermal communication with and electrically isolated from the framework. The photovoltaic cells are supported at the target areas defined by the reflector. The apparatus further includes a transparent window joined to the framework such that the photovoltaic cells are disposed within a protected space.

[0013] in another example, a method includes forming two side portions from a metallic material, and forming two end portions from a metallic material. The method also includes joining the side portions and the end portions such that a box-like framework is defined. The method also includes joining a reflector to the framework. The reflector is configured to concentrate light onto one or more target locations. The method further includes supporting a plurality of photovoltaic cells by way of the framework. The photovoltaic cells are supported at the target locations. The method also includes joining a transparent window to the framework such that the photovoltaic cells are within a protected space.

ILLUSTRATIVE SYSTEM

[0014] Reference is now made to FIG. 1 , which depicts a schematic view of a system 100. The system is illustrative and non-limiting with respect to the present teachings. Other systems, devices, components, materials, and operations are also contemplated by the present teachings and can be used. The system 100 is also referred to as a solar energy system 100 for purposes herein.

[0015] The system 100 includes a concentrating-type photovoltaic (PV) unit or panel 102 according to the present teachings. The panel 102 is characterized by features described below. The panel 102 is configured to receive solar energy (i.e., photonic energy or radiation) 104 from the sun 106 and provides an output of electrical energy 108. The panel 102 is joined to a sun tracking apparatus 1 10 by way of a tracker support or "yoke" 1 12.

[0016] The sun tracking apparatus 1 10 is configured to angularly adjust the position of the panel 102 in accordance with the apparent motion of the sun 106 across the sky during daylight hours. Thus, the panel 102 is aimed or positioned to maintain about maximum solar exposure by way of the sun tracking apparatus 1 10. The system 100 also includes a tracking controller (control) 1 14 that operates or drives the sun tracking apparatus 1 10 by way of control signaling 1 16 during typical normal operations.

[0017] The system 100 further includes an electrical load 1 18. The electrical load 1 18 can be defined by or include any suitable constituency including, for non-limiting example, a storage battery or batteries, a charge controller, a power inverter, a computer, wireless communications equipment, a motor-driven machine, and so on. Other suitable electrical loads 1 18 can also be used. The electrical load 1 18 is coupled to receive electrical energy 108 from the panel 102. The system 100 is illustrative of any number of systems or configurations contemplated by the present teachings.

ILLUSTRATIVE PANEL ASSEMBLAGE

[0018] Attention is now turned to FIG. 2, which depicts an isometric-like assemblage (or exploded) view of a concentrating-type PV panel (panel) 200. The panel 200 is illustrative and non-limiting in nature. Thus, other panels, concentrating-type devices, apparatus and systems are also contemplated by the present teachings. [0019] The pane! 200 includes a framework 202 defined by respective side portions 204 and 206, and respective end portions 208 and 210. The respective portions 204-210 are each formed from sheet metal material and are depicted assembled such that the framework 202 is defined by a box-like form factor.

[0020] The panel 200 also includes a first electrical series circuit 212 and a second electrical series circuit 214. Each of the series circuits 212 and 214 includes five PV cells 218. Other circuits including other numbers of PV cells are also contemplated. The series circuit 212 is supported on the side portion 204, and the series circuit 214 is supported on the side portion 206, when the panel 200 is in a final, fully-assembled state. Each of the series circuits 212 and 214 is constructed by way of flexible electrical conductors 217 coupled (i.e., conductively bonded) to the PV cells 218.

[0021] The panel 200 also includes a reflector 218. The reflector 218 is formed to define (or is characterized by) a plurality of double-curvature regions 220, each configured to concentrate photonic energy (i.e., light) onto a respective spot-like target area. In one example, the reflector 218 is formed from a monolithic thermoplastic substrate having a reflective (or dichroic) surface treatment. Other configurations or materials can also be used. The reflector 218 is configured to be joined to a lower edge portion of the framework 202 by way of a peripheral feature or edge 222 using an adhesive, fasteners, or in another suitable way.

[0022] The panel 200 also includes a cover 224. The cover 224 is formed from a rigid material such as sheet metal or plastic. The cover 224 is joined to the framework 202 in a final, fully-assembled state, and functions to protect the reflector 218 against damage caused by impacts or environmental factors or contaminants. The panel 200 also includes a transparent window 226. The transparent window is joined to an upper edge portion of the framework 202 and functions to protect the interior of the reflector 218, the PV cells 216, or other aspects of the panel 200 against environmental contaminants. The transparent window 226 can be formed from plastic, glass, or another suitable material or materials.

[0023] The panel 200 further includes a heat pipe 228 and a heat pipe 230.

The heat pipes 228 and 230 are configured to be received within respective channels defined about the periphery of the framework 202. During typical, normal operation, each heat pipe 228 and 230 functions to receive excess thermal energy from respective ones of the PV cells 216 and to distribute that thermal energy along the mass of the framework 202. In turn, the framework 202 dissipates that thermal energy to the ambient environment. Thus, the heat pipes 228 and 230 function to increase the effectiveness of heat removal from the PV cells 216.

ILLUSTRATIVE APPARATUS

[0024] Reference is now directed to FIG. 3, which depicts an isometric-like view of an apparatus 300. The apparatus 300 is illustrative and non-limiting in nature. Other apparatus, devices, assemblages and systems are contemplated by the present teachings.

[0025] The apparatus 300 includes the panel 200 as described above in a fully assembled state. The apparatus also include a tracker support (or yoke) 302. The tracker support 302 includes a base 304 and respective end portions 306 and 308. The end portion 306 is mechanically engaged to the framework 202 by way of end portion 208, while the end portion 308 is engaged to the end portion 210.

[0026] The base 304 is configured to be coupled or mechanically engaged to a sun tracking apparatus (e.g., 110). The panel 200 can be angularly positioned in one or two axis so as to follow the apparent path of the sun (e.g., 106) by way of the tracker support 302. The tracker support 302 is formed from a rigid material or materials such as aluminum, plastic, and so on. Other suitable materials can also be used.

ILLUSTRATIVE END DETAILS

[0027] Attention is now turned to FIG. 4, which depicts an isometric-like view of selected end-wise details of the apparatus 300. The end portion 308 of the tracker support 302 includes respective extension portions 308A and 308B. The extension portion 308A includes or is characterized by a protrusion or "dog" 320, while the extension portion 308B includes a protrusion 322. The protrusions 320 and 322 are configured to be received within corresponding apertures 240 and 242, respectively, defined by the end portion 210 of the framework 202.

[0028] The extensions 320 and 322 and the corresponding apertures 240 and 242 are elevationally coincident with the peripheral edge 222 of the reflector 218 when the panel 200 is in a fully assembled state. As a result, desirable alignment (i.e., relative positioning) of the reflector 218 and the tracker support 302 is achieved. Other relative positioning of panel 200 features can also be used.

[0029] Electrical energy derived by the PV cells 216 is routed out of the pane! 200 by way of respective conductors 250 and 252. The respective series circuits 212 and 214 can thus be electrically coupled to an electrical load (e.g., 1 18) or other entity external to the panel 200 by way of conductors 250 and 252 or other similar conductive elements.

ILLUSTRATIVE SECTION DETAILS

[0030] Reference is now made to FIG. 5, which depicts a section view of a pane! 200 according to the present teachings. The particular details of depicted in FIG. 5 are illustrative and non-limiting with respect to the present teachings. Other constituencies, materials, form-factors or configurations can also be used.

[0031] The side portion 204 is formed or folded so as to define a channel

260, while the side portion 206 is similarly formed to define a channel 262. The heat pipe 228 is received and supported within the channel 260 and is bonded or secured in thermal communication with the side portion 204. in turn, the heat pipe 230 is bonded in thermal communication with the side portion 206 within the channel 262.

[0032] The cover 224 is joined or coupled to the respective side portions

204 and 206, and underlies the reflector 218. The transparent window 226 is joined or bonded to the respective side portions 204 and 206, and overlies the reflector 218. The side portions 204 and 206 and the cover 224 and the transparent window 226 are thus portions of a substantially enclosed volume or space that contains the reflector 218.

[0033] An illustrative light (i.e., photonic energy) ray 502 passes through the transparent window 226 and is directed (or concentrated) onto a PV cell 216A by way of a double-curvature region 220A. Similarly, an illustrative light ray 504 passes through the transparent window 226 and is directed (or concentrated) onto a PV cell 216B by way of a double-curvature region 220B. Thus, the respective double-curvature regions 220A and 220B concentrate light energy onto spot-like target areas disposed on generally opposite internal sides of the panel 200.

ILLUSTRATIVE METHOD

[0034] Reference is now made to FIG. 6, which depicts a flow diagram of a method according to another example of the present teachings. The method of FIG. 8 includes particular steps and proceeds in a particular order of execution. However, it is to be understood that other respective methods including other steps, omitting one or more of the depicted steps, or proceeding in other orders of execution can also be used. Thus, the method of FIG. 6 is illustrative and non-limiting with respect to the present teachings. Reference is also made to FIGs. 1 -5 in the interest of understanding the method of FIG. 8.

[0035] At 800, respective side and end portions of a framework are formed. For purposes of a present example, respective side portions 204 and 206, and end portions 208 and 210, are formed from stamped and folded sheet metal, such as aluminum. Other materials or fabrication techniques can also be used.

[0036] At 802, the side and end portions are joined together to define a framework. For purposes of the present example, the side portions 204 and 208 and the end portions 208 and 210 are joined such that a box-like framework 202 is defined. The joining can be performed by way of rivets, threaded fasteners, welding, epoxy bonding or other suitable technique. [0037] At 804, a reflector is formed having light-concentration regions and joined to the framework. For purposes of the present example, a reflector 218 is formed of thermoplastic and a reflective surface treatment of aluminum is applied or deposited to at least one surface. The reflector 218 is characterized by a plurality of double-curvature regions 220 each configured to concentrate photonic energy (e.g., sunlight) onto a spot-like target area by virtue of the reflective surface treatment. The reflector 218 is then bonded to about a lower edge of the framework 202 by way of epoxy or another suitable adhesive.

[0038] At 806, PV cell circuitry is supported within the framework in accordance with the target areas defined by the reflector. Within the present example, respective series circuits 212 and 214, each including a number of PV cells 218 electrically connected in series arrangement, are supported on the side portions 204 and 208, respectively. Each of the PV cells 218 is located coincident to a respective light concentration target area defined by the reflector 218. The PV cells 216 are in thermal communication with, and are electrically isolated from, the framework 202.

[0039] At 808, a cover is formed and joined to the framework beneath the reflector. Within the present example, a cover 224 is formed from aluminum sheet metal and is joined to the framework by way of adhesive, fasteners or other suitable technique. The cover 224 generally underlies and functions to protect the reflector 218 from damaging impacts, environmental contaminants or the like.

[0040] At 810, a transparent window is formed and joined to the framework overlying the reflector. Within the present example, a transparent window 228 is formed from light-transparent plastic and is adhesively bonded about an upper edge of the framework 202. Other materials or bonding/joining techniques can also be used. A panel 200 is thus defined according to the constituency and techniques of the instant illustrative method.

[0041] The method described above can be suitably modified according to the present teachings. For example, the series circuits 212 and 214 can be electrically coupled to each other such that a single series circuit is defined, in another example, the series circuits 212 and 214 can be electrically coupled to an external entity such as an electrical load (e.g., 118). In yet another example, the resulting panel 200 can be mechanically joined to a sun tracking apparatus (e.g., 1 10) by way of a tracker support (e.g., 302). in still another example, respective heat pipes 228 and 230 can be bonded within channels 260 and 262 so as to aid in the transfer of unneeded heat from the PV cells 216 to the framework 202. Other suitable steps or elements can also be used.

[0042] in general and without limitation, the present teachings contemplate solar energy panels that are fabricated such that unitary constructs are defined. Each panel includes or is defined by a framework of metallic side and end portions. A reflector includes a number of light-concentrating regions bearing a reflective (or dichroic) surface treatment, each configured to concentrate photonic energy onto a target area. The reflector is joined to the framework. PV cells, electrically connected to define one or more circuits, are supported within the framework and are coincident with the target areas defined by the reflector.

[0043] A cover is joined to the framework to protect an underside or lower aspect of the reflector, and a transparent window is joined to the framework to protect the reflector and PV circuitry from weather, debris or other environmental hazards. The reflector and the PV cells are thus supported within a protected, generally enclosed space by virtue of the transparent window, framework and cover. Electrical conductors extend outward from the panel so as to convey electrical energy from the PV cells to a load or other entity that is external to or remote from the panel.

[0044] The panel can be joined to a sun tracker apparatus by way of a yoke or tracker support. The panel can thus be angularly repositioned so as to follow the apparent motion of the sun across the sky. Systems Including any number of panels according to the present teachings can be manufactured, configured and used.

[0045] In general, the foregoing description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the invention should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the invention is capable of modification and variation and is limited only by the following claims.

Claims

CLAIMS What is claimed is:

1. An apparatus, comprising:

a framework having a channel about the periphery thereof;

a reflector joined to the framework, the reflector configured to concentrate photonic energy on one or more target areas;

one or more photovoltaic cells in thermal communication with and electrically isolated from the framework, the photovoltaic cells supported at the target areas; and

a transparent window joined to the framework such that the photovoltaic cells are disposed within a protected space.

2. The apparatus according to claim 1 further comprising a tracker support configured to mechanically join the framework to a sun tracking apparatus.

3. The apparatus according to claim 1 further comprising a heat pipe configured to distribute thermal energy along the framework generated by incomplete light to electrical energy conversion by the photovoltaic cells, the framework configured to dissipate thermal energy to an ambient environment.

4. The apparatus according to claim 3, the heat pipe disposed at least in part within the channel.

5. The apparatus according to claim 1 , the photovoltaic cells being electrically coupled so as to define at least one series circuit,

6. The apparatus according to claim 1 , the framework defined by two side portions and two end portions joined to define a box-like form-factor.

7. The apparatus according to claim 6, each of the side portions and the end portions formed from a sheet metal material or an extrudable metal.

8. The apparatus according to claim 1 , the reflector including a monolithic tbermoformed substrate and bearing either a reflective or dichroic surface treatment on at least a portion thereof.

9. The apparatus according to claim 1 , the reflector defining a plurality of double-curvature regions configured to define a corresponding plurality of spot-like target areas.

10. The apparatus according to claim 1 , the reflector defining a pair of single curvature regions configured to define a pair of symmetric target areas.

11 . The apparatus according to claim 1 further comprising a cover joined to the framework and disposed about a backside aspect of the reflector.

12. A method, comprising:

forming two side portions from a metallic material;

forming two end portions from a metallic material;

joining the side portions and the end portions such that a box-like framework is defined;

joining a reflector to the framework, the reflector configured to concentrate light onto one or more target locations;

supporting a plurality of photovoltaic cells by way of the framework, the photovoltaic cells supported at the target locations; and

joining a transparent window to the framework such that the photovoltaic cells are within a protected space.

13. The method according to claim 12, the two side portions being equivalent to each other, the two end portions being equivalent to each other.

14. The method according to claim 12 further comprising electrically coupling the photovoltaic cells such that one or more series circuits are defined.

15. The method according to claim 12 further comprising joining a tracking yoke to the framework, the tracking yoke configured to couple the framework to a sun tracking apparatus.