WO2018157497A1 - Double-sided solar cell assembly and system - Google Patents

Abstract

A double-sided solar cell assembly and a system using same. The double-sided solar cell assembly comprises a front tempered glass (10), a first bonding layer (20), a solar cell set (30), a second bonding layer (40), and a back tempered glass (50) that are stacked in sequence from top to bottom. The solar cell set (30) is formed by connecting double-sided solar cells (31) in series or in parallel. The double-sided solar cells (31) are welded together by means of welding strips. The front tempered glass (10) and the back tempered glass (50) are provided with light-transmissive holes (60). The light-transmissive holes (60) are provided in gap regions (70) among the double-sided solar cells (31). The double-sided solar cell assembly is simple in structure, lower in cost, and large in generated power.

Description

Double-sided solar cell module and system Technical field

The present invention relates to the field of solar cells, and more particularly to a double-sided solar cell module and system.

Background technique

The solar cell module is the core part of the solar power generation system. Its function is to convert solar energy into electrical energy, and then send the electricity to the storage battery to store it or push the load to work. A solar cell is a device that effectively absorbs solar radiation energy and converts light energy into electrical energy by using the photovoltaic effect. When the sun shines on the semiconductor PN junction, a new hole-electron pair (VE pair) is formed. Under the action of the electric field of the PN junction, holes flow from the N region to the P region, and electrons flow from the P region to the N region, and a current is formed after the circuit is turned on.

The double-sided solar cell module not only absorbs direct light from the front of the sun, but also absorbs the sun's rays reflected from the back object. Therefore, for a double-sided solar cell module, the influence of the component design on the overall power generation needs to be considered.

Summary of the invention

The technical problem to be solved by the present invention is to provide a double-sided solar cell module which has a simple structure, a low cost, and a large power generation capability of the battery assembly.

The technical problem to be solved by the present invention is also to provide a solar cell system which has a simple structure, a low cost, and a large power generation capability of the battery assembly.

In order to solve the above technical problems, the present invention provides a double-sided solar cell module comprising a front side tempered glass, a first bonding layer, a solar cell group, a second bonding layer and a back tempered glass which are laminated in this order from top to bottom. The solar battery group is formed by connecting double-sided solar cells in series or in parallel, and the double-sided solar cells are welded together by a welding strip;

The double-sided solar cell includes a back silver main gate, an aluminum gate line, a back passivation layer, a P-type silicon, an N-type emitter, a front passivation layer, and a positive silver electrode, and the back passivation layer is formed by laser grooving 30-500 parallel laser-grooving zones, at least one set of laser grooving units in each laser grooving zone; aluminum grid The wire is disposed in one-to-one correspondence with the laser grooved area, and the aluminum gate line is connected to the P-type silicon through the laser grooved area; the aluminum gate line is vertically connected to the back silver main gate;

The front tempered glass and the back tempered glass are provided with light-transmissive holes, and the light-transmissive holes are disposed in a gap region between the double-sided solar cells.

As a preferred mode of the above aspect, the size of the gap region between the double-sided solar cells is 0.5-10 cm, and the size of the light-transmitting hole is smaller than the size of the slit region between the double-sided solar cells, the light-transmitting hole The size is 0.4-9cm.

As a preferred mode of the above aspect, the light transmission hole is a circular hole, an elliptical hole, a triangular hole, a quadrangular hole, a pentagonal hole or a hexagonal hole.

As a preferred mode of the above solution, when at least two sets of laser grooving units are disposed in each laser grooving zone, the distance between adjacent two sets of laser grooving units arranged in parallel is 5-300 μm.

As a preferred mode of the above aspect, the pattern of the laser grooving unit is a line, a circle, an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, a cross or a star.

As a preferred mode of the above solution, the pattern of the laser grooving unit is a continuous straight line or a broken line composed of a plurality of line segments;

When the pattern of the laser grooving unit is a broken line composed of a plurality of line segments, the lengths of the line segments are the same or different.

As a preferred mode of the above aspect, the laser grooving zone has a width of 10-500 μm; the width of the aluminum grid line located below the laser grooving zone is greater than the width of the laser grooving zone, and the width of the aluminum grid line is 30-550 μm.

As a preferred mode of the above aspect, the double-sided solar cell is a double-sided single crystal solar cell or a double-sided polycrystalline solar cell.

As a preferred mode of the above aspect, the first bonding layer and the second bonding layer are a bonding layer made of an ethylene-vinyl acetate copolymer;

The frame is a metal frame.

The front tempered glass and the back tempered glass are ultra-white tempered coated glass having a light transmittance of more than 90%.

Accordingly, the present invention also discloses a solar cell system comprising the above-described double-sided solar cell module.

The implementation of the present invention has the following beneficial effects:

The invention adopts a front and back tempered glass with a light transmission hole, and the reverse of the double-sided solar battery system The optical medium re-reflects the sunlight passing through the light-transmitting hole to the back surface of the module, increases the solar energy received by the back of the module, and improves the photoelectric conversion efficiency of the back surface of the battery pack, thereby integrally increasing the power generation of the double-sided solar battery module.

In addition to providing a light-transmissive hole in the front back tempered glass, the present invention also employs a specific double-sided solar cell, specifically a P-type PERC double-sided solar cell, which has a plurality of parallelly arranged aluminum grid lines on the back of the battery. It not only replaces the all-aluminum back electric field in the existing single-sided solar cell, but also functions as a back-side light absorption function, and is also used as a sub-gate structure in the back silver electrode for conducting electrons. The P-type PERC double-sided solar cell of the invention can save the dosage of the silver paste and the aluminum paste, reduce the production cost, and realize the double-sided absorption of light energy, significantly expand the application range of the solar cell and improve the photoelectric conversion efficiency.

When the P-type PERC double-sided solar cell is matched with the front and back tempered glass provided with a light-transmissive hole, the power generation amount of the solar cell module can be remarkably improved, and the power generation amount is increased by 5% to 20%.

DRAWINGS

Figure 1 is a front elevational view of a double-sided solar cell module of the present invention;

Figure 2 is a plan view of the double-sided solar cell module shown in Figure 1;

Figure 3 is a cross-sectional view of the double-sided solar cell of Figure 1;

4 is a schematic view showing an embodiment of a back surface structure of the double-sided solar cell shown in FIG. 3;

Figure 5 is a schematic view showing another embodiment of the back structure of the double-sided solar cell shown in Figure 3;

Fig. 6 is a schematic view showing still another embodiment of the back structure of the double-sided solar cell shown in Fig. 3.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings.

As shown in FIG. 1 and FIG. 2, the present invention provides a double-sided solar cell module comprising a front tempered glass 10, a first bonding layer 20, a solar cell 30, and a second bonding layer laminated in this order from top to bottom. 40 and the back tempered glass 50, wherein the solar battery cells 30 are formed by connecting the double-sided solar cells 31 in series or in parallel, and the double-sided solar cells 31 are welded together by a solder ribbon.

The front tempered glass 10 and the back tempered glass 50 are provided with a light transmission hole 60. The light transmission hole 60 is disposed in the gap region 70 between the double-sided solar cells 31, and can increase the solar energy received by the back surface of the component. Improve the photoelectric conversion efficiency of the back of the battery pack, thereby improving the overall development of the double-sided solar cell module Electricity.

The size of the slit region 70 between the double-sided solar cells 31 is 0.5-10 cm, and the size of the light-transmitting holes 60 is smaller than the size of the slit region 70 between the double-sided solar cells, and the size of the light-transmitting holes 60 It is 0.4-9cm. The position and size of the light-transmissive aperture 60, its relationship with the slit region 70, is directly related to the physical and chemical properties of the solar cell module and the extent to which the back surface receives light energy. Since the general photovoltaic modules are applied to high-temperature and high-humidity coastal areas, or plateaus or desert areas with very long sunshine hours, the characteristics are all harsh environments, so solar cell modules are required to have good barrier properties, scratch resistance, and UV resistance. And chemical resistance. The present invention provides the light-transmitting hole 60 in the gap region 70 between the double-sided solar cells, and ensures that the size thereof is smaller than the slit region 70, and can maintain good barrier properties without affecting the physical and chemical properties of the solar cell module. Scratch resistance, UV resistance and chemical resistance) increase the light energy received on the back side of the module and improve the photoelectric conversion efficiency on the back side of the battery pack, thereby increasing the power generation of the double-sided solar cell module as a whole.

The light transmission hole 60 is preferably a circular hole, an elliptical hole, a triangular hole, a quadrangular hole, a pentagonal hole or a hexagonal hole. It should be noted that the light transmission hole 60 may also have other shapes, such as an octagonal hole, a dodecagonal hole, an irregular polygonal hole, and the like, and the embodiment is not limited to the embodiment of the present invention.

In addition to providing a light-transmissive hole in the front back tempered glass, the present invention also employs a specific double-sided solar cell. As shown in FIG. 3, the double-sided solar cell 31 includes a back silver main gate 1, an aluminum gate line 2, a back passivation layer, a P-type silicon 5, an N-type emitter 6, a front passivation layer 7, and a positive silver electrode 8. The back passivation layer includes a back surface silicon nitride film 3 and a back surface aluminum oxide film 4, and the front passivation layer 7 may be a front side silicon nitride film 7, but is not limited thereto.

The back silicon nitride film 3 and the back aluminum oxide film 4 are laser-grooved to form 30-500 sets of laser-grooving areas 9 arranged in parallel, and each of the laser-groove areas is provided with 1-50 sets of laser grooving units; The aluminum gate lines 2 are disposed in one-to-one correspondence with the laser grooved regions 9 which are connected to the P-type silicon 5 through the laser grooved region 9; the aluminum gate lines 2 are vertically connected to the back silver main gate 1.

The invention improves the existing single-sided PERC solar cell, no longer has an all-aluminum back electric field, but turns it into a plurality of aluminum grid lines 2, using a laser grooving technique on the back side silicon nitride film 3 and the back side. A laser grooving zone 9 is formed on the aluminum oxide film 4, and the aluminum gate line 2 is printed on these parallel-arranged laser grooving zones 9, so that local contact with the P-type silicon 5 can be formed, and the densely arranged aluminum grid lines 2 are arranged. It can not only improve the open circuit voltage Voc and the short circuit current Jsc, reduce the minority carrier recombination rate, and improve the photoelectric conversion efficiency of the battery. It can replace the all-aluminum back electric field of the existing single-sided battery structure, and the aluminum grid line 2 does not. Full coverage of silicon On the back side of the film, sunlight can be projected from the aluminum grid line 2 into the silicon wafer, thereby realizing absorption of light energy on the back side of the silicon wafer and greatly improving the photoelectric conversion efficiency of the battery.

Preferably, the number of the aluminum grid lines 2 corresponds to the number of laser grooved areas, which are 30-500, and more preferably, the number of the aluminum grid lines 2 is 80-220.

As shown in FIG. 4, the back surface of the silicon wafer, the aluminum gate line 2 is vertically connected to the back silver main gate 1, wherein the back silver main gate 1 is a continuous straight gate, and the back silicon nitride film 3 and the back aluminum oxide film 4 are provided. The laser grooving zone 9 prints the aluminum paste to form the aluminum grid line 2, and the aluminum paste is filled into the laser grooving zone 9, so that the aluminum grid line 2 forms a partial contact with the P-type silicon 5, and the electrons can be transmitted to the aluminum grid line 2, The back silver main gate 1 intersecting the aluminum grid line 2 collects electrons on the aluminum grid line 2, and thus, the aluminum grid line 2 of the present invention functions to increase the open circuit voltage Voc and the short-circuit current Jsc, and reduce minority carriers. The compounding rate and the function of transmitting electrons can replace the all-aluminum back electric field in the existing single-sided solar cell, which not only reduces the amount of silver paste and aluminum paste, but also reduces the production cost, and realizes double-sided absorption of light energy, significantly expanding the solar cell. Application range and improved photoelectric conversion efficiency.

In addition to the arrangement of the continuous straight grid as shown in FIG. 4, the back silver main grid 1 of the present invention may also be arranged in intervals, as shown in FIG. It can also be arranged in intervals, and each adjacent segment is connected by a connecting line, as shown in FIG. 6.

It should be noted that more than two sets of laser grooving units are arranged in the laser grooving zone, and the distance between adjacent two sets of laser grooving units arranged in parallel is 5-300 μm.

Each set of laser grooving units includes at least one laser grooving unit, and the pattern of the laser grooving unit is a line, a circle, an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, a cross or a star. The aluminum grid line 2 may be linear, curved, wavy, or zigzag, but is not limited thereto. The arrangement of each group of laser grooving units may also be linear, curved, wavy, zigzag, but is not limited thereto. The shape of the aluminum grid line is the same as that of each group of laser slotting units.

Preferably, the pattern of the laser grooving unit is a continuous straight line or a dotted line composed of a plurality of line segments; when the pattern of the laser grooving unit is a broken line composed of a plurality of line segments, the lengths of the line segments are the same or different .

The width of the laser grooving zone 9 of the present invention is 10-500 μm; the width of the aluminum grid line 2 located below the laser grooving zone 9 is greater than the width of the laser grooving zone 9, and the width of the aluminum grid line 2 is 30-550 μm. In the above-mentioned aluminum grid line 2 width selection of a large value such as 500 μm, and the laser slotted area 9 width selection of a small value such as 40 μm, multiple sets of laser slotted areas 9 can be arranged side by side on the same aluminum grid line 2, to ensure aluminum The gate line 2 has a sufficient contact area with the P-type silicon 5.

Therefore, the P-type PERC double-sided solar cell of the present invention is provided with a plurality of aluminum gate lines 2 arranged in parallel, which not only replaces the all-aluminum back electric field in the existing single-sided solar cell, but also uses the back side light absorption, and is also used in the back silver electrode. The sub-gate structure serves as conduction electrons. The P-type PERC double-sided solar cell of the invention can save the dosage of the silver paste and the aluminum paste, reduce the production cost, and realize the double-sided absorption of light energy, significantly expand the application range of the solar cell and improve the photoelectric conversion efficiency.

Further, the double-sided solar cell 31 may be a double-sided single crystal solar cell or a double-sided polycrystalline solar cell, but is not limited thereto.

The front tempered glass and the back tempered glass are ultra-white tempered coated glass with a light transmittance of more than 90%, which can transmit sunlight to the battery to the greatest extent, avoid loss of sunlight due to refraction and reflection, and due to tempering The coated glass has a high strength and therefore better protects the inside of the assembly.

The first bonding layer 20 and the second bonding layer 40 are a bonding layer made of ethylene-vinyl acetate copolymer (EVA). The first bonding layer 20 and the second bonding layer 40 are used for bonding and fixing the tempered glass and the solar battery. The ethylene-vinyl acetate copolymer (EVA) has good water resistance, high corrosion resistance and good processability. And anti-vibration, can ensure the battery pack has a long service life.

The assembly of the present invention is fixed around the frame 80, and a junction box 90 for connecting the positive and negative electrodes of the solar battery pack 30 is mounted outside the back tempered glass 50. Wherein, the frame is a metal frame, which is used to protect the component and has a certain sealing and supporting function. The metal frame may be an aluminum frame, but is not limited thereto. The junction box 90 is used to connect components and components to increase the power generation of the solar power plant.

Correspondingly, the present invention also discloses a solar cell system comprising the above double-sided solar cell module. As a preferred embodiment of the solar cell system, the above-described double-sided solar cell module, battery pack, charge and discharge controller inverter, AC power distribution cabinet, and solar tracking control system are included. The solar cell system may be provided with a battery pack, a charge and discharge controller inverter, or a battery pack or a charge and discharge controller inverter, and those skilled in the art may set according to actual needs.

It should be noted that in the solar cell system, components other than the double-sided solar cell module can be designed with reference to the prior art.

It should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention, although the present invention will be described in detail with reference to the preferred embodiments, The technical solutions of the present invention may be modified or equivalently substituted without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

A double-sided solar cell module comprising a front side tempered glass, a first bonding layer, a solar cell group, a second bonding layer and a back tempered glass laminated in this order from top to bottom, the solar cell group The two-sided solar cells are connected in series or in parallel, and the double-sided solar cells are welded together by a solder ribbon; The double-sided solar cell includes a back silver main gate, an aluminum gate line, a back passivation layer, a P-type silicon, an N-type emitter, a front passivation layer, and a positive silver electrode, and the back passivation layer is formed by laser grooving 30-500 laser-grooved areas arranged in parallel, at least one set of laser grooving units are arranged in each laser grooving zone; the aluminum grid lines are arranged in one-to-one correspondence with the laser grooving zone, and the aluminum grid lines are slotted by laser The region is connected to the P-type silicon; the aluminum gate line is vertically connected to the back silver main gate; The front tempered glass and the back tempered glass are provided with light-transmissive holes, and the light-transmissive holes are disposed in a gap region between the double-sided solar cells. A double-sided solar cell module according to claim 1, wherein a size of the gap region between the double-sided solar cells is 0.5 - 10 cm, and the size of the light-transmissive holes is smaller than a gap between the double-sided solar cells The size of the area, the size of the light transmission hole is 0.4-9 cm. The double-sided solar cell module according to claim 2, wherein the light-transmitting holes are circular holes, elliptical holes, triangular holes, quadrangular holes, pentagonal holes or hexagonal holes. A double-sided solar cell module according to claim 1, wherein when at least two sets of laser grooving units are disposed in each laser grooving zone, a spacing between adjacent two sets of laser grooving units arranged in parallel is 5-300 μm. The double-sided solar cell module according to claim 1, wherein the pattern of the laser grooving unit is a line, a circle, an ellipse, a triangle, a quadrangle, a pentagon, a hexagon, a cross or a star. . A double-sided solar cell module according to claim 1, wherein said laser slotting list The pattern of the element is a continuous straight line or a dotted line composed of a plurality of line segments; When the pattern of the laser grooving unit is a broken line composed of a plurality of line segments, the lengths of the line segments are the same or different. A double-sided solar cell module according to claim 1, wherein said laser grooving zone has a width of 10-500 μm; an aluminum gate line located below said laser grooving zone has a width greater than a width of said laser grooving zone, and aluminum The width of the gate line is 30-550 μm. A double-sided solar cell module according to claim 1, wherein said double-sided solar cell is a double-sided single crystal solar cell or a double-sided polycrystalline solar cell. The double-sided solar cell module according to claim 1, wherein the first adhesive layer and the second adhesive layer are adhesive layers made of ethylene-vinyl acetate copolymer; The frame is a metal frame; The front tempered glass and the back tempered glass are ultra-white tempered coated glass having a light transmittance of more than 90%. A solar cell system comprising the double-sided solar cell module of any one of claims 1-9.

Images