Back-Contact Solar Cell Module With Flexible Interconnected Bar
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Solution Overview
Problem
Existing flexible solar cell modules face challenges in precision and efficiency due to small cell sizes, complex electrode welding, and shading effects from interconnected bars, which limit design flexibility and power generation efficiency.
Innovation Solution
A flexible and rollable back-contact solar cell module is developed, allowing large cell blocks to be connected in series or parallel using a flexible interconnected bar, with electrodes on the back side to avoid shading and facilitate welding, and a protective layer attached to the light-receiving side using an adhesive layer, enabling infinite extension and reconfiguration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If small cell pieces are used to form flexible solar modules, then flexibility and adaptability are improved, but manufacturing precision and processing difficulty increase significantly
Solution Approach 1:
The solar cell is divided into positive and negative electrode regions on the back side, with each region containing multiple electrode groups. This segmentation allows for modular assembly and reduces the precision required for each individual connection point while maintaining overall module flexibility.
Solution Approach 2:
The patent moves all electrodes to the back side of the solar cell, transitioning from a planar front-side electrode layout to a three-dimensional back-side configuration. This dimensional change eliminates the need for precise front-side electrode alignment while preserving flexibility.
2Adaptability or versatility
If small cell pieces are used with electrodes on different sides, then series welding is required, but process complexity and time consumption increase
Solution Approach 1:
Multiple electrode groups of the same polarity are merged into single large electrode regions on the back side. This combining reduces the number of individual welding operations required, as entire electrode regions can be connected in parallel rather than requiring multiple separate welds for each small cell piece.
Solution Approach 2:
The positive and negative electrode regions are pre-configured on the back side during cell fabrication, so that when cells are assembled into modules, the electrode connections are already optimized. This preliminary arrangement reduces on-site welding complexity and time consumption.
3Reliability
If interconnected bars are welded on the front surface, then electrical connection is achieved, but shading effect reduces power generation efficiency
Solution Approach 1:
Instead of placing electrodes and interconnected bars on the front surface where they block light, the patent inverts the configuration by moving all electrodes to the back side. This inversion allows light to pass through the entire front surface unobstructed, eliminating shading losses while maintaining reliable electrical connections on the rear.
4Reliability
If high precision attaching is required for small cell pieces, then module performance is maintained, but processing difficulty and cost increase
Solution Approach 1:
The back side of the solar cell is designed with localized electrode regions that have specific geometric configurations optimized for their function. This local quality optimization allows for tolerant assembly processes, as the electrode geometry itself provides alignment guidance and reduces the precision requirements for attaching and connecting operations.
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
The solution enhances design flexibility, improves processing convenience, and increases light utilization by avoiding shading, allowing for customizable current and voltage configurations and efficient welding, while maintaining high conversion efficiency.
Implementation Method 1
a protective layer is attached to a surface of a light-receiving side by using an adhesive layer
Data Source
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AI summary
A flexible and rollable back-contact solar cell module, wherein a length of it can be extended infinitely and the back-contact solar cell module includes a plurality of large cell blocks connected in series or in parallel. The large cell block includes a plurality of small cell strings connected in series or in parallel. The small cell string includes a plurality of small square cell pieces connected in series or in parallel. The series-connection or the parallel-connection between the large cell blocks, the small cell strings, or the small square cell pieces is achieved by welding a flexible interconnected bar in the horizontal or vertical direction. Electrodes of the small square cell pieces are all on a back side and the small square cell pieces are formed by cutting a back-contact solar cell. A protective layer is attached to a surface of a light-receiving side by using an adhesive layer.