Shingled Solar Module Interconnect for Gap-Free Cell Overlap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional solar cell modules face inefficiencies due to gaps between cells required for ribbon connections, leading to reduced area utilization and potential stress-induced cracking from ribbon shapes and attachment methods.
Innovation Solution
The use of crystalline silicon solar cells arranged in a shingled manner with separate front and rear metallization ribbons of varying cross-sectional widths, allowing for overlapping connections without gaps and reducing stress through flat rear ribbons and thin copper film pads for improved electrical conductivity and assembly accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If traditional ribbon connections are used between solar cells, then electrical connections can be established, but gaps between cells are required which reduces area utilization
Solution Approach 1:
The interconnection system is divided into two separate ribbon components: a front ribbon connecting front pads and a rear ribbon connecting rear pads. This segmentation allows the ribbons to be positioned on opposite sides of the overlapping cell region, enabling electrical connections without requiring lateral gaps between cells, thus achieving full area utilization while maintaining connection reliability
Solution Approach 2:
The solution transitions from a planar connection approach to a three-dimensional arrangement by utilizing both the front and rear surfaces of the solar cells for connections. The front ribbon connects front pads while the rear ribbon connects rear pads, effectively using the vertical dimension (front-to-back depth of cells) to resolve the spatial conflict between connection requirements and area utilization
2Reliability
If ribbons are used to connect solar cells, then electrical connections are established, but stress-induced cracking may occur from ribbon shapes and attachment methods
Solution Approach 1:
By separating the connection function into front and rear ribbons, each ribbon can be optimized for its specific location and stress conditions. The front ribbon can be designed with appropriate flexibility for front surface attachment, while the rear ribbon can be configured to minimize stress on the cell edges, thereby reducing the risk of stress-induced cracking while maintaining reliable electrical connections
Solution Approach 2:
Different ribbon configurations and materials can be used for front and rear connections based on the specific stress conditions and electrical requirements at each location. The front ribbon may have different cross-sectional properties compared to the rear ribbon, allowing each to be locally optimized for its function while minimizing overall stress on the cell structure
3Ease of manufacture
If conventional ribbon attachment methods are used, then electrical connections are established, but extensive adhesive or high-temperature soldering is required
Solution Approach 1:
The invention introduces thin copper film pads as intermediary elements between the ribbons and the solar cell contacts. These copper film pads serve as compliant mounting surfaces that facilitate reliable electrical connections through simpler attachment methods, reducing the need for extensive adhesive application or high-temperature soldering while maintaining connection reliability
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 configuration enhances area utilization, reduces series resistance, increases module efficiency, and minimizes stress on solar cells, allowing for more effective light exposure and reliable electrical connections without the need for extensive adhesive or high-temperature soldering.
Implementation Method 1
solar radiation impinging on the surface of, and entering into, the substrate of a solar cell creates electron and hole pairs in the bulk of the substrate
Data Source
AI summary
A high efficiency configuration for a solar cell module comprises solar cells arranged in an overlapping shingled manner and methods for assembling solar cells in a shingled manner. Solar cells in the module are electrically connected in series by front side ribbons and separate rear side ribbons. The front-side ribbons have a smaller cross-sectional width while the rear-side ribbons are thinner and wider.