Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
  • H02S30/00—Structural details of PV modules other than those related to light conversion
  • H02S30/20—Collapsible or foldable PV modules
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02S—GENERATION OF ELECTRIC POWER BY CONVERSION OF INFRARED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
  • H02S40/00—Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
  • H02S40/30—Electrical components
  • H02S40/36—Electrical components characterised by special electrical interconnection means between two or more PV modules, e.g. electrical module-to-module connection
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy

Definitions

• the present invention is in the field of a Miura-Ori Photovoltaic Module, for converting light into electricity, i.e. a module that can easily be unfolded and folded and hence be trans ported or transferred easily, and a system comprising at least two of such modules and optionally comprising further elements.
• a solar cell, or photovoltaic (PV) cell is an electrical device that converts energy of light, typically sun light (hence “solar”), directly into electricity by the so-called photovoltaic effect.
• the solar cell may be considered a photoelectric cell, having electrical characteristics, such as current, voltage, resistance, and fill factor, which vary when exposed to light and which vary from type of cell to type.
• Solar cells are described as being photovoltaic irrespective of whether the source is sun light or an artificial light. They may also be used as photo detector.
• a solar cell When a solar cell absorbs light it may generate either electron-hole pairs or excitons. In or der to obtain an electrical current charge carriers of opposite types are separated. The separated charge carriers are “extracted” to an external circuit, typically providing a DC-current. For prac tical use a DC-current may be transformed into an AC-current, e.g. by using a transformer.
• solar cells are grouped into an array of elements.
• Various elements may form a panel, and various panels may form a system.
• Wafer based c-Si solar cells contribute to more than 90% of the total PV market. Accord ing to recent predictions, this trend will remain for the upcoming years towards 2020 and many years beyond. Due to their simplified process, conventional c-Si solar cells dominate a large part of the market. As alternative to the industry to improve the power to cost ratio, the silicon hetero junction approach has become increasingly attractive for PV industry, even though the relatively complicated process to deploy the proper front layers, such as a thermal conductive oxide (TCO) and an inherent low thermal budget of the cells limiting usage of existing production lines and thus result in a negligible market share so far.
• TCO thermal conductive oxide
• a heterojunction is the interface that occurs be tween two layers or regions of dissimilar crystalline semiconductors.
• a homojunction relates to a semi conductor interface formed by typically two layers of similar semiconductor material, wherein these semiconductor materials have equal band gaps and typically have a different doping (either in concentration, in type, or both).
• a common example is a homojunction at the interface be tween an n-type layer and a p-type layer, which is referred to as a p-n junction.
• a homojunction at the interface be tween an n-type layer and a p-type layer, which is referred to as a p-n junction.
• advanced techniques are used to precisely control a deposition thickness of layers involved and to create a lattice-matched abrupt interface.
• Three types of heterojunctions can be distin guished, a straddling gap, a staggered gap, and a broken gap.
• solar cells are typically pro vided in small arrays, having a limited number of cells, such as less then 20 cells. They may be used outdoors, providing basic electrical power, such as to appliances. In an alternative these cells may be unfolded in space.
• WO 2016/070225 Al recites a portable photovoltaic unit and a photovoltaic system.
• the system comprises a plurality of interconnectable photovoltaic module units each unit comprising a photovoltaic device.
• the units are arranged for releasably coupling to each other so that an electrical interconnection between an N-side of a unit and a P-side of the next unit is established and energy can be accessed from electrical contacts that are disposed on the same side of one of the units.
• the units are typically non-flexible, whereas joints or contacts between units are flexible. The units themselves appear not to be foldable. Despite the system being portable folding thereof is still relatively cumbersome.
• US 2018/323743 Al recites modular photovoltaic (PV) system can include a PV cell, a frame coupled to the PV cell, and a converter.
• the frame is configured to support a plurality of pairs of externally accessible connectors, each pair having a positive voltage connector and a negative voltage connector, the positive voltage connector of each pair of the plurality electri cally connected to each other and the negative voltage connector of each pair of the plurality electrically connected to each other.
• the converter is configured to receive voltage from the PV cell and change the voltage for output at one or more pairs of the externally accessible connect ors.
• the converter may include Maximum Power Point Tracking services to manage the power output from the PV cell.
• Multiple PV systems may be connected to each other in coplanar and non-coplanar relationships.
• the frames have triangular, rectangular, or other polygonal shapes.
• the modules are typically non-flexible, whereas joints or contacts be tween units are flexible. The modules themselves appear not to be foldable, as a frame is pro vided
• the present invention relates to an improved foldable solar cell array which overcomes one or more of the above disadvantages, without jeopardizing functionality and advantages.
• the present invention relates in a first aspect to a foldable array of PV-cells accord ing to claims 1, which is lightweight and portable.
• the present foldable array (10) of PV-cells comprises at least n*m PV-cells electrically connected to one and another, wherein n>2 and m>2, and at least four magnetic array-array connectors (2,3), which may be ejectable or fixed, hence in an retracted configuration or in an ejected configuration, at least two for a positive elec trical array-array contact (2), and at least two for a negative array-array contact (3), wherein at least one positive electrical array-array connector extends in a horizontal direction and wherein at least one positive electrical array-array connector extends in a vertical direction and wherein at least one negative electrical array-array connector extends in a horizontal direction and wherein at least one negative electrical array-array connector extends in a vertical direction, and wherein each connector is electrically insulated, wherein each PV-cell has a geometric
• the foldable array may simply be folded by “pushing” corners inward, and may be unfolded by moving opposite corners away from one and another. In view of folding it is preferred to comprise a hinge mechanism in the foldable module. In view of folding/unfolding it is also preferred to have PV-cells with rather straight (closer to 90 degrees) corners, than to use very acute/sharp corners. Corners between re spectively 70-110 degrees are preferred, such as corners between about 80-about 100 degrees. At every edge of a PV-cells, or likewise block of PV-cells, typically one fold line is present. De pending on a size of PV-cells one may combine a number of PV-cells into sub-cells, as in fig. 2. Therewith a lightweight, portable, and foldable, easily connectable array of PV-cells is provided.
• the PV module is lightweight and can be unfolded and fold with one single movement. Modularity is at the core of the design, as several of these foldable modules can be (interconnected to form a PV array of in principle any layout and size. The flexibility increases a variation in use.
• This modularity allows to go from small simple applications to full PV systems with just the addition of PV modules.
• the invention allows modules to be carried easily in large quantities and be connected as needed.
• Current foldable modules are either very small with low output power or in need of heavy equip ment for transportation. This solution allows very easy deployment with the use of only one ac tuator.
• High-efficiency crystalline silicon solar cells can be used, and low weight is ensured by the use of a lightweight encapsulation layer and transparent flexible foil.
• the backside of the module is made out of a flexible foil, such as a black or white foil. This ensures a very pleasant aesthetic appeal.
• the module may be provided with an encapsulating layer to fur ther ensure hermeticity and safety of use.
• the present invention relates to a system comprising at least two arrays according to the invention.
• the arrays are electrically connected by magnetic contacts, and there with the connection is secured.
• the magnetic contacts are not very thick, so that the arrays can still be folded easily and do not occupy much space when folded.
• the magnetic contacts may be made of a flexible material, such as an electrically conductive tape/adhesive. They may also be incorporated in a layer or layers, protecting them from the environment. Therewith electrical power can be provided, especially under sunny conditions.
• the array, or system may also be oriented towards the sun, preferably perpendicular to sunlight emitted by the sun, the yield can be increased simply by rotating the array or system accordingly. Now and then rotating can be repeated in order to compensate for rotation of the earth.
• the present invention provides a solution to one or more of the above-mentioned problems.
• the present invention relates in a first aspect to a foldable array of PV-cells, and in a second aspect to a system comprising at least two such arrays.
• each cell may comprise 2-24 sub-cells 11, such as 4-12 sub-cells.
• an array provides a maxi mum output of 20-200 W, in particular 30-100W, such as 40-60 W.
• a lower output may for in stance be used for loading a small electronic device, such as a telephone, and a larger array for loading/supporting a communication system.
• the geometrical form may be selected from rectangles, such as squares, paralepidid, such as diamond. Th geo metrical form and the foldability are typically adapted to one and another.
• the PV-cells may be selected from conventional homo-junction and heterojunction solar cells, mono-facial and bi-facial solar cells, n-type and p-type mono-crystalline Si, micro-crystalline Si bulk, front contacted solar cells, back contacted solar cells, front and rear junction solar cells, interdigitated back contacted solar cells, and combinations thereof.
• the present foldable array of PV-cells may have a thickness of 10-100 um.
• the present foldable array of PV-cells may comprise an anti -reflective coating.
• the PV-cells may be provided on a polymeric backside film, such as a transparent backside film (which film may also be referred to as a “foil”, typically a polymeric foil, such as an elastomeric foil), wherein the polymer is preferably selected from PE, PET, and PP.
• a polymeric backside film such as a transparent backside film (which film may also be referred to as a “foil”, typically a polymeric foil, such as an elastomeric foil)
• the polymer is preferably selected from PE, PET, and PP.
• the backside film may have a thickness of 10-100 um.
• the PV-cells comprise a polymeric frontside film, such as a transparent frontside film (which film may also be referred to as a “foil”, typically a polymeric foil, such as an elastomeric foil), wherein the poly mer is preferably selected from PE, PET, and PP.
• a polymeric frontside film such as a transparent frontside film (which film may also be referred to as a “foil”, typically a polymeric foil, such as an elastomeric foil)
• the poly mer is preferably selected from PE, PET, and PP.
• the frontside film may have a thickness of 10-100 um.
• a third film may be provided on the frontside or backside of the array, or on both.
• the PV-cells may comprise at least one light-weight encapsulation layer, typically at either side of the PV- cells, such as a transparent elastic polymer layer, such as of Ethylene Vinyl acetate (EVA).
• EVA Ethylene Vinyl acetate
• En capsulation may be achieved by EVA (Ethylene Vinyl acetate) which is a transparent elastic pol ymer that once is heated up to 150 °C becomes liquid and once is cooled down acts as a glue of the different components of the module.
• EVA Ethylene Vinyl acetate
• Commercial modules use EVA to glue glass and Tedlar to the solar cells produce the modules, but due to the glass they cannot be flexible.
• a thickness of said encapsulation layer may be from 10-100 pm, such as 20-30 pm, each individually.
• the present foldable array of PV-cells array may have a surface area of > 10 cm 2 , and a mass of ⁇ 1 gr/cm 2 .
• the array may be portable.
• the present foldable array of PV-cells may further com prise at least one component selected from a junction box, an electrical connection, a trans former, power electronics, and an electrical power storage unit.
• At least one fold line com prises at least one hinge (30), wherein the hinge preferably comprising at least one insulating material (31,33) at an outer side thereof, and wherein the hinge preferably comprises an electri cal connector for connecting a group of cells with an adjacent group of cells. Therewith electrical connection between adjacent groups of PV-cells is secured over time.
• the magnetic connector may be selected from iron comprising materials.
• magnetic array- array connectors may be provided at an edge of the array, preferably at the end of an edge.
• each magnetic connector in dividually is located at a fixed position relative to an array, such as at a side thereof at a fixed distance from a corner of the array, such as at 1-5 cm from the comer.
• the magnetic connector each individually may have a contact area of 0.5-10 cm 2 , preferably 1-5 cm 2 , such as 3.2+1 cm 2 , and/or a diameter of 2+1.3 cm, and/or a thickness of 1-15 mm, preferably 2-10 mm, such as 7 mm.
• the magnetic connector may be a magnet to MC4 connector (both +/-) adaptor is provided, such that integra tion of the flexible magnetic modules with commercially available power electronics is properly ensured.
• the present system may comprise an embedded charging station, such as for a mobile phone.
• the present system may comprise power electronics and/or an adaptable junction box.
• Figure la shows a way of folding an array 10 of PV-cells, with valley fold lines 9 and mountain fold lines 8.
• Figure lb shows four sub-cells 11.
• Figure 2 shows schematics of the present foldable module with a front side film 21, an op tional front side encapsulation layer 22, a PV-layer 23, an optional back side encapsulation layer 24, and a back side film 25.
• Figure 3 shows an even variant of an array 10, with 4 columns, each column having 4 cells.
• a cell is electrically connected to an adjacent cell by connection 4, the + and - indicating the polarity of the respective PV-cell terminal.
• Columns of cells are either attached at a top side (column 1-2 and column 3-4) or at a bottom side (column 2-3). Therewith a serial con nection of cells is provided.
• Fig. 4a shows schematically a serial contacted array 10 with only one positive and only one negative magnetic contact indicated.
• Such an array can not be connected in series or parallel with other similar arrays, at least not without forming a regular patter and layout. Therefore, four neg ative magnetic contacts 3 and four positive magnetic contacts 2 are shown in fig. 4b.
• the magnetic interconnects can be at opposite ends of the module, and there may be a need of 4 magnets per side.
• the above is a transparent foil/foil flexible module with the 8 magnetic connectors (exaggerated for better view), and the detail of them can be viewed in fig. 5.
• the magnetic contacts of either polarity are electrically interconnected by respective electrical con nections 5.
• Figure 5 shows an enlargement of the magnetic contacts 2,3, each individually surrounded by insulator 7.
• the idea of these 4 magnetic connectors per side is to eliminate any wiring be tween the modules no matter what interconnection scheme (series or parallel) you want to prolude.
• the black line around the module is a flexible frame. Also isolation of the magnetic con nectors may be needed to avoid any accidental short circuit during connection.
• the connectors may also comprise detachment means, such as springs; one can use springs that can give the magnets the ability to be released by pressing them, the spring will pop the connector out.
• Series interconnection is done by simple rotation of the module, whereas parallel interconnection is achieved by horizontal arrangement
• Fig. 6a shows a layout of an array with even columns, and a way to indicate respective cells by n, ie [1-n], and m, j e [1-m]
• Fig. 6b shows an example of at least two negative magnetic contacts 3 and two positive magnetic contacts 2, provided at a bottom side, at either right/left side of the array.
• the preferred output voltages of the PV panels are preferably sufficient enough so they can be properly used on applications ranging from 5 VDC to 96 VDC.
• the smallest panel could prolose around 8 - 10 VDC and the largest around 30 VDC, then series interconnection can ramp up the voltage to be suited with a commercially available MPPT trackers and charge controllers (in case batteries are also used on the system).
• Currents could range from 2 A (required by most modern devices) to 6 - 10 A for full area cells (5 in and 6 in).
• Embedded AC conversion is also possible with smart power electronics.
• the magnets are electrically connected to the +/- terminals of the PV-modules.
• the area of the magnets could be around 3.2 cm 2 (a diameter of around 2 cm with thickness of around 7 mm).
• the current produced by large area solar cells can be safely handled by magnets of this size.
• Fig. 9 shows four panels, comprising a group of PV-cells, forming part of the present fold- able array. In between panels one hinge 30 is provided, of which at the bottom side an example is given, without the further elements of figure 10.
• Fig. 10 shows a cross-section of the present hinge 30, which functions as a reinforcement, insulating cover central 31 for electrically isolating the hinge, insulating cover wire 32 for elec trically insulating wire 32, connecting rod 33, and electrical wire 34 for electrically connecting one panel to an adjacent panel. So different panels of the Miura-Ori are connected by hinges.
• the hinge design has a connecting rod in its center, covered by an insulating material.
• the tab bing wire coming from the interconnected cells of a panel is attached (when necessary, not all shingles conduct current) to both ends of the rod. This way one panel is connected to the next to built the Miura-Ori Solar module.
• insulated tape is used to increase safety.
• the insulating cover consists of two parts to allow the fold and unfold movement. This mechanism allows the fold and unfold movement of the panels without affect ing the tabbing wire, increasing reliability
• Fig. 11 shows an enlargement of fig. 5, with positive magnetic connectors 2 at a bottom side, with negative magnetic connectors 3 at a top side, having a centrally located electrical con ductor 6, and surrounded by electrical insulator 7.
• the magnetic contacts are placed at the same height on opposite sides of the solar module. This allows the ease interconnection of more than two Miura-Ori modules in series, doubling the power capacity without the need of cables.
• MC4 Connectors as shown bellow. These connect ors are cheap to obtain, the cable can be design such as to be magnetically connected to each end of the array. This requires a special (but not complex) design of one end of the cable. In this way only a pair of cables will be sufficient for a multi-module array. The length of the cable will be defined by the application, and therefore, the final capacity of the array.

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• 2020
  • 2020-04-09 NL NL2025309A patent/NL2025309B1/en active
• 2021
  • 2021-04-01 WO PCT/NL2021/050215 patent/WO2021206542A1/en not_active Ceased
  • 2021-04-01 CN CN202180037071.7A patent/CN115668753B/zh active Active
  • 2021-04-01 EP EP21718977.8A patent/EP4133591A1/de active Pending

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