Solar Cell Module Bulging Rear Encapsulant

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Solution Overview

Problem

Current solar cell modules face challenges in reliability and output characteristics, with existing encapsulants not adequately addressing issues of acetic acid generation and light path efficiency.

Innovation Solution

A solar cell module design featuring a light-receiving side encapsulant without ethylene-vinyl acetate copolymer and a colored rear side encapsulant with ethylene-vinyl acetate copolymer, where the rear side encapsulant bulges towards the light-receiving surface, creating a short light path and minimizing acetic acid discharge, while maintaining structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional encapsulant containing ethylene-vinyl acetate copolymer is used on both light-receiving side and rear side, then the encapsulant provides good sealing and structural support, but acetic acid is generated and discharged causing deterioration of the solar cell module

Engineering Contradiction:

Improvemodule reliabilityVSAvoidacetic acid discharge

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The encapsulant is divided into two separate layers: a light-receiving side encapsulant without ethylene-vinyl acetate copolymer and a rear side encapsulant containing ethylene-vinyl acetate copolymer. This segmentation isolates the acetic acid-generating material to the rear side only, preventing acetic acid discharge toward the light-receiving surface while maintaining the beneficial sealing properties where needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different encapsulant materials are applied to different regions: the light-receiving side uses an encapsulant free of ethylene-vinyl acetate copolymer to prevent acetic acid generation, while the rear side uses an encapsulant containing ethylene-vinyl acetate copolymer for optimal sealing. This local differentiation addresses the harmful acetic acid discharge only where it occurs without compromising overall module reliability.

Inventive Principle:

Principle #3Local quality

2Productivity

If the rear side encapsulant is positioned flat against the solar cell rear surface, then the structure is simple and manufacturing is easy, but the light path length is excessive reducing light incidence efficiency

Engineering Contradiction:

Improvelight incidence efficiencyVSAvoidencapsulant structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The rear side encapsulant is designed with a bulging shape that protrudes toward the light-receiving surface, creating a curved interface rather than a flat one. This curvature shortens the optical path length for light traveling through the module, improving light incidence efficiency and potentially enhancing light reflection back toward the solar cell active layers.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The rear side encapsulant extends in the vertical dimension by bulging upward toward the light-receiving surface, transforming from a two-dimensional flat layer to a three-dimensional protruding structure. This dimensional change effectively reduces the optical path length without requiring changes to the horizontal module dimensions or solar cell layout.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If the interface between encapsulants does not contact the solar cell side surface, then manufacturing is simpler, but acetic acid can discharge more freely causing deterioration

Engineering Contradiction:

Improvemodule reliabilityVSAvoidencapsulant assembly

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The interface between the light-receiving side encapsulant and rear side encapsulant serves as an intermediary barrier structure that contacts the solar cell side surface. This interface acts as a physical blockage that prevents acetic acid generated in the rear side encapsulant from discharging toward the light-receiving surface, while the bulging shape ensures this barrier is positioned optimally to intercept acetic acid migration paths.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 design enhances reliability by preventing acetic acid-induced deterioration and improves output characteristics by optimizing light incidence efficiency, resulting in a more reliable and efficient solar cell module.

Implementation Method 1

a colored rear side encapsulant... creating a short light path

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS9209334B2Solar cell module

Publication Date: 2015.12.08 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A solar cell module includes an encapsulant and a solar cell in the encapsulant. The encapsulant includes a light-receiving side encapsulant at a light-receiving surface side of the solar cell, and a colored rear side encapsulant at a rear surface side of the solar cell. The rear side encapsulant contains an ethylene-vinyl acetate copolymer. An interface between the rear side encapsulant and the light-receiving side encapsulant is in contact with a side surface of the solar cell. In a part of an area where no solar cell is provided, the rear side encapsulant bulges to the light-receiving surface side.