Ethylene/Alpha-Olefin Encapsulant for PID-Resistant Solar Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ethylene/vinyl acetate copolymers used in solar cell encapsulants face issues with acetic acid gas generation and high voltage potential differences leading to reduced output and potential-induced degradation (PID), necessitating a material with high volume resistance and light transmittance for solar cell modules.
Innovation Solution
An ethylene/alpha-olefin copolymer with specific density, melting temperature, and elution temperature ranges, prepared using transition metal compounds as catalysts, achieving a narrow molecular weight distribution and balanced crystallinity distribution for high volume resistance and light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ethylene/vinyl acetate copolymer is used as solar cell encapsulant, then adhesiveness and processability are improved, but acetic acid gas is generated causing harmful effects on solar cell device
Solution Approach 1:
The patent changes the chemical composition parameters by replacing vinyl acetate units with alpha-olefin units in the copolymer structure. This substitution eliminates the decomposition pathway that generates acetic acid gas while maintaining the desired adhesiveness and processability characteristics through careful selection of copolymer composition and molecular weight distribution.
Solution Approach 2:
The patent employs a conventional ethylene/alpha-olefin copolymer system that can be processed using existing manufacturing infrastructure, replacing the need for specialized materials while achieving the goal of eliminating harmful gas generation through compositional modification rather than fundamental process changes.
2Loss of energy
If system voltage is increased to reduce transmission loss, then power transmission efficiency is improved, but potential difference between frame and cells increases causing PID phenomenon
Solution Approach 1:
The encapsulant material acts as an intermediary between the solar cells and the frame, providing electrical insulation that prevents charge accumulation and PID phenomenon. By selecting a copolymer with appropriate volume resistance characteristics, the material mediates the electrical interaction between components while allowing the system to operate at higher voltages for improved transmission efficiency.
Solution Approach 2:
The patent modifies the electrical parameters of the encapsulant by controlling the copolymer composition and crystallinity to achieve optimal volume resistance. This parameter optimization allows the encapsulant to provide sufficient electrical insulation for high-voltage systems, preventing PID while maintaining the benefits of increased system voltage for reduced transmission loss.
3Reliability
If volume resistance is increased to prevent PID, then electrical insulation is improved, but light transmittance may be compromised
Solution Approach 1:
The patent applies local quality by creating distinct functional regions within the encapsulant material through controlled crystallinity distribution. The amorphous regions provide high light transmittance for optimal solar cell performance, while the crystalline regions contribute to enhanced volume resistance for PID prevention. This spatial differentiation of material properties allows simultaneous optimization of both electrical and optical characteristics.
Solution Approach 2:
The copolymer structure functions as a composite material system where ethylene and alpha-olefin units create distinct structural domains. The crystalline ethylene-rich regions provide electrical insulation through high volume resistance, while the amorphous alpha-olefin-rich regions maintain optical clarity for light transmittance. This composite architecture enables the encapsulant to simultaneously satisfy both electrical and optical performance requirements.
Data Source
AI summary
The present invention relates to an ethylene/alpha-olefin copolymer having excellent volume resistance and light transmittance, and a method for preparing the same.