Infrared Reflective Backsheet for Building-Integrated PV Modules

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Solution Overview

Problem

Building-integrated photovoltaic modules face efficiency losses due to increased operating temperatures caused by dark backsheets that absorb infrared radiation, leading to reduced electricity conversion efficiency.

Innovation Solution

A multi-layer backsheet design with an infrared-reflective first layer and a highly reflective second layer, adjacent to each other, to enhance infrared and visible light reflection, reducing the operating temperature of photovoltaic modules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If dark backsheets (carbon black or iron oxide pigments) are used for aesthetic reasons to blend with architectural colors, then the aesthetic appearance is improved, but the operating temperature of the photovoltaic module increases due to infrared absorption, reducing efficiency

Engineering Contradiction:
Improveaesthetic appearanceVSAvoidoperating temperature
Core Design Contradiction:
ShapeVSTemperature

Solution Approach 1:

The backsheet is divided into multiple layers: a first layer containing carbon black or iron oxide pigment for aesthetic appearance, and a second layer containing infrared-reflective pigment (such as barium sulfate, zinc oxide, or titanium dioxide) for thermal management. This segmentation allows each layer to perform its specific function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the backsheet have different properties: the first layer provides dark coloration for aesthetic integration with building surfaces, while the second layer provides infrared reflectivity for temperature control. Each layer is optimized for its local function.

Inventive Principle:
Principle #3Local quality

2Shape

If dark backsheets are used to maximize aesthetic integration with building structures, then the visual blending is improved, but the electricity conversion efficiency decreases due to heat absorption

Engineering Contradiction:
Improvevisual blendingVSAvoidelectricity conversion efficiency
Core Design Contradiction:
ShapeVSProductivity

Solution Approach 1:

The backsheet is divided into multiple layers: a first layer containing carbon black or iron oxide pigment for aesthetic appearance, and a second layer containing infrared-reflective pigment (such as barium sulfate, zinc oxide, or titanium dioxide) for thermal management. This segmentation allows each layer to perform its specific function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the backsheet have different properties: the first layer provides dark coloration for aesthetic integration with building surfaces, while the second layer provides infrared reflectivity for temperature control. Each layer is optimized for its local function.

Inventive Principle:
Principle #3Local quality

3Shape

If carbon black pigment is used to absorb all visible light for dark appearance, then the aesthetic integration is improved, but infrared light is also absorbed, increasing backsheet temperature and reducing module efficiency

Engineering Contradiction:
Improvedark appearanceVSAvoidinfrared energy absorption
Core Design Contradiction:
ShapeVSLoss of energy

Solution Approach 1:

The backsheet is divided into multiple layers: a first layer containing carbon black or iron oxide pigment for aesthetic appearance, and a second layer containing infrared-reflective pigment (such as barium sulfate, zinc oxide, or titanium dioxide) for thermal management. This segmentation allows each layer to perform its specific function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the backsheet have different properties: the first layer provides dark coloration for aesthetic integration with building surfaces, while the second layer provides infrared reflectivity for temperature control. Each layer is optimized for its local function.

Inventive Principle:
Principle #3Local quality

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 multi-layer backsheet design effectively reduces the operating temperature of photovoltaic modules, enhancing their electricity conversion efficiency by reflecting infrared and visible light, thus improving energy output.

Implementation Method 1

a first layer having a reflectance of more than 25% of a light with a wavelength anywhere from 1000 nm to 2100 nm

Methodology Applied
Scientific EffectInfrared reflection: Reflection

Implementation Method 2

a second layer having a reflectance of more than 50% of all light with a wavelength from 380 nm to 2000 nm

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

The multi-layer backsheet design effectively reduces the operating temperature of photovoltaic modules, enhancing their electricity conversion efficiency by reflecting infrared and visible light

Methodology Applied
Scientific EffectThermal radiation reflection: Reflection

Data Source

PatentEP2839512B1A backsheet for a photovoltaic module using infrared reflective pigments
Publication Date: 2020.11.18 HONEYWELL INTERNATIONAL INC
  • EP2839512B1 patent drawingFigure 1
  • EP2839512B1 patent drawingFigure 2
  • EP2839512B1 patent drawingFigure 3

AI summary

A multi-layer backsheet for a photovoltaic module comprising a first layer having a reflectance of more than 25% of a light with a wavelength anywhere from about 1000 nm to about 2100 nm, and a reflectance of less than 35% of all light with a wavelength from about 380 nm to about 750 nm; and a second layer having a reflectance of more than 50% of all light with a wavelength from about 380 nm to about 2000 nm. A photovoltaic module comprising the multi-layer backsheet, a method of making the photovoltaic module, and a method of converting sunlight into electricity by exposing the photovoltaic module to sun light.