Transparent Junction Box Housing for Bifacial Solar Modules

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Solution Overview

Problem

Bifacial solar modules face efficiency reduction due to shading caused by traditional black plastic junction boxes, which limit the utilization of both direct and indirect light for electricity generation.

Innovation Solution

The junction box is made of optically transparent materials, such as glass or specific polymers, with high light transmittance in the visible range, reducing shading and enhancing energy harvesting from both sides of the solar module.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional black plastic junction box is used, then the junction box provides good electrical insulation and protection, but it causes shading on the back surface that reduces light utilization and efficiency

Engineering Contradiction:
Improveelectrical insulation and protectionVSAvoidlight utilization and efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The junction box housing is changed from traditional black plastic to an optically transparent material. This color/transparency change allows light to pass through the housing and reach the solar cells on the back surface, eliminating the shading effect while maintaining the electrical insulation and protection functions through appropriate material selection.

Inventive Principle:
Principle #32Color changes

2Reliability

If the junction box is made larger to accommodate electrical components, then better electrical protection is achieved, but more shading area on the back surface reduces efficiency

Engineering Contradiction:
Improveelectrical protectionVSAvoidshading area on back surface
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

By making the junction box transparent, the housing material itself no longer creates shading regardless of its size. This allows the junction box to be sized appropriately for electrical component accommodation without the traditional compromise of creating shaded areas on the back surface that would reduce light utilization.

Inventive Principle:
Principle #32Color changes

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 use of transparent materials for the junction box housing increases the solar module's efficiency by allowing more light to be utilized, improving energy generation from both direct and reflected sources.

Implementation Method 1

the housing of the junction box is made of a material that is optically transparent in the wavelength range from 380nm to 1100nm

Methodology Applied
Scientific EffectOptical transparency: Absorption (EM radiation)

Implementation Method 2

A bifacial solar module has the property of using light incident on the front surface as well as light incident on the back surface to generate electricity

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP4115519B1Bifacial solar module
Publication Date: 2023.09.27 HANWHA Q CELLS GMBH
  • EP4115519B1 patent drawingFigure 1~3

AI summary

The invention relates to a bifacial solar module having a front side surface and a back side surface and comprising: - a front side encapsulation element (1) forming the front side surface of the solar module, - a plurality of solar cells (2) which are electrically connected to one another, - a rear side encapsulation element (3) forming the rear side surface of the solar module with a rear side surface plane, and - at least one junction box (4) which is arranged at least partially on the rear side surface and has a housing (41), characterised in that the housing (41) is formed from a material which is optically transparent in the wavelength range from 380nm to 1100nm.