Solar Cell Module Cleaved Surface Buffering
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Solution Overview
Problem
Crystalline solar cell modules with cleaved surfaces have lower conversion efficiency and reliability due to the deterioration of module characteristics and mechanical weakness of cleaved surfaces, which are exacerbated by stacking and modularization processes.
Innovation Solution
A solar cell module design where cleaved surfaces of one solar cell serve as a shading section and are buffered with an insulating member to prevent damage during stacking, and the use of an electroconductive member to connect the solar cells while minimizing shading areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If solar cells are stacked with peripheries overlapping to reduce non-power generation areas, then module power generation efficiency is improved, but mechanical strength and reliability deteriorate due to cleaved surface weakness
Solution Approach 1:
An insulating member is introduced as an intermediary between adjacent solar cells at their overlapping peripheries. This insulating member protects the mechanically weak cleaved surfaces from direct contact and potential damage during stacking, while still allowing the solar cells to maintain their overlapping configuration for maximizing power generation efficiency.
Solution Approach 2:
The insulating member is positioned in advance at the overlapping peripheries of solar cells to provide protective cushioning. This beforehand protection prevents mechanical damage to the cleaved surfaces that would occur during the stacking process and under subsequent operational stresses, thereby improving module reliability without sacrificing the overlapping design.
2Ease of manufacture
If cleaved surfaces are used for stacking solar cells, then manufacturing efficiency is improved, but conversion efficiency and reliability deteriorate due to deterioration of module characteristics
Solution Approach 1:
The insulating member acts as a mediator that allows the use of cleaved surfaces for efficient stacking while preventing the deterioration of module characteristics. By positioning the insulating member at the overlapping peripheries, the cleaved surfaces can be used for manufacturing efficiency without directly contacting each other, thus avoiding the deterioration of conversion efficiency and reliability.
3Reliability
If electroconductive member connects solar cells at overlapping peripheries, then electrical connection is improved, but shading area increases reducing power generation
Solution Approach 1:
The insulating member is selectively positioned only at specific locations where the peripheries of adjacent solar cells overlap, rather than covering entire surfaces. This localized application protects the cleaved surfaces at critical contact points while leaving the majority of the solar cell surfaces exposed to light, thus minimizing shading area and maintaining high power generation efficiency.
Solution Approach 2:
Instead of providing complete coverage with insulating material, the solution uses partial action by positioning insulating members only where absolutely necessary at the overlapping peripheries. This minimal intervention approach ensures electrical connection reliability is maintained while keeping shading areas to the absolute minimum required for structural protection.
Data Source
AI summary
In the solar cell module, a first solar cell and a second solar cell are stacked together with an electroconductive member interposed therebetween, such that a cleaved surface-side periphery on a light-receiving surface of the first solar cell overlaps a periphery on a back surface of the second solar cell. The first solar cell and the second solar cell each have: photoelectric conversion section including a crystalline silicon substrate; collecting electrode; and back electrode. At a section where the first solar cell and the second solar cell are stacked, the collecting electrode of the first solar cell and the back electrode of the second solar cell are electrically connected to each other by coming into contact with the electroconductive member. An insulating member is provided on a part of the cleaved surface-side periphery on the light-receiving surface of the first solar cell, where the collecting electrode is not provided.