Overlapping Solar Cell Interconnection via Switching Points
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Solution Overview
Problem
Current solar cell connection methods result in significant inactive surface area not utilized for energy conversion, risk of short circuits, and complex, space-intensive connection structures, which hinder efficient manufacturing and performance.
Innovation Solution
The method involves applying photoelectrically active layers and contacts to an insulating substrate, with direct interconnection using a contact material that bridges the substrate, allowing for series and parallel connections on one side or between sides of overlapping solar cells, reducing inactive area and simplifying the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If individual solar cells are arranged at a defined distance and connected using contact elements or flat conductors, then short circuits are prevented, but a significant proportion of inactive surface is created that cannot be used for energy conversion
Solution Approach 1:
The patent merges the connection function with the active surface by applying contact materials directly on the solar cell surface at defined switching points, eliminating the need for separate contact elements and flat conductors that create inactive areas. This integration allows the connection structure to become part of the active energy-converting surface.
Solution Approach 2:
The patent transitions from planar connections using flat conductors to three-dimensional contact structures that extend vertically from the solar cell surface. Contact materials are applied in layered configurations with different heights, creating vertical interconnections that minimize horizontal space occupation and preserve active surface area.
2Ease of manufacture
If contact materials such as solder, conductive adhesives or conductive pastes are used for connecting solar cells, then electrical connection is achieved, but short circuits can occur at solar cell edges due to damaged or imprecisely arranged connectors
Solution Approach 1:
The patent divides the connection process into discrete switching points where contact materials are precisely applied only at specific locations on the solar cell surface. This segmentation prevents contact materials from spreading to adjacent cells and causing short circuits, while still achieving reliable electrical connections at the intended switching points.
Solution Approach 2:
The patent introduces an insulating substrate as an intermediary layer between adjacent solar cells. This substrate provides physical separation and electrical insulation, preventing short circuits between cells while allowing contact materials to be applied directly on the solar cell surfaces without risk of bridging to neighboring cells.
3Adaptability or versatility
If the optically inactive rear contact area is used for interconnection, then solar cells can be contacted on the front, but a relatively large proportion of inactive solar cell surface is created that is not used for energy conversion
Solution Approach 1:
The patent utilizes the vertical dimension by applying contact materials at different heights on the solar cell surface, creating multi-level switching points. This allows front-side contact configuration while minimizing the horizontal footprint of contact areas, thereby preserving more active surface area for energy conversion.
Solution Approach 2:
The patent applies contact materials with locally optimized properties at specific switching points rather than using extensive rear contact areas. The contact materials are precisely positioned and sized to provide necessary electrical connections while minimizing the area occupied, converting a uniform inactive region into localized functional contact points.
4Reliability
If soldering paste is applied in an intermediate step with thermal processing, then series/parallel connection is achieved, but the manufacturing process becomes complex and time-consuming with precise positioning requirements
Solution Approach 1:
The patent merges the contact material application and solar cell positioning into a single integrated step. Contact materials are applied directly on the solar cell surface at the final switching point locations, eliminating the need for separate soldering steps and intermediate positioning operations. This reduces manufacturing complexity while maintaining connection reliability.
Solution Approach 2:
The patent performs preliminary preparation of contact materials and switching point definitions before solar cell assembly. Contact materials are pre-configured with appropriate conductive properties and positioning features, allowing direct application and immediate functional connection without requiring subsequent thermal processing or adjustment steps.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach minimizes inactive surface area, enhances light absorption by up to 10%, reduces the risk of short circuits, and simplifies the manufacturing process, enabling more efficient and durable solar cell modules with improved shading tolerance and power output.
Implementation Method 1
planar rigid or flexible solar cells (1) whose photoelectrically active layers (3) are applied to an insulating substrate material (2)
Implementation Method 2
the solar cells (1) are directly interconnected once or several times with contact material (10) or switching points (22) with a contact material (10) in the overlapping region
Data Source
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AI summary
The invention relates to an arrangement and circuit, and to a method for interconnecting flat rigid or flexible solar cells, the photoelectrically active layers thereof being applied to an insulating substrate material. The aim of the invention is to provide a novel arrangement and circuit and an associated method for interconnecting flat solar cells, reducing the risk of short circuit and the inactive surface area in the matrix composite of a solar module and selectively allowing simple interconnection, both as a parallel circuit and as a series circuit in production. The solar cells (1) in the arrangement and circuit of flat rigid or flexible solar cells are disposed overlapping in the contact area to one or more adjacent solar cells (1), as is already known as such. Said solar cells (1) are interconnected to each other directly once or a plurality of times in a novel manner, having a contact material (10) at the overlapping area to each other, using contact material (10) or switching points (22). In the method, an electrically conductive layer is generated on an entire solar cell matrix made of a plurality of overlapping solar cells (1) at individual or, if necessary, selectively at a plurality of (optionally a great many of) switching points (22), by means of screen printing, dispensing, spraying, vaporization, sputtering, or galvanically precipitating. Said layer, or the corresponding number of layers, are then applied pointwise to the corresponding locations so that the back side contact (7) of each of the upper solar cells (1) is connected to the front side contact (17) of the immediately adjacent overlapping solar cell (1). The contact material (10) can be applied and disposed here as a continuous strand or as individual or a plurality of contacts in one or more switching points (22). The invention can be applied for rigid or flexible solar cells, particularly those produced using thin film technology. Said solar cells can also be individual, discrete solar cells, or also a plurality of so-called monolithically interconnected solar cells on a common substrate material.