Photovoltaic Module With Localized Contact Elements For Thermal Stress

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing photovoltaic module production methods face challenges such as increased material costs, production delays, and risk of cell breakage due to different thermal expansion coefficients between glass and silicon, as well as inefficiencies in heat dissipation and mechanical stress on cells.

Innovation Solution

A photovoltaic module design utilizing localized contact elements (LKE) for selective, minimal fixation and spacing between cover layers, allowing for sliding contact and adhesive connections to manage thermal expansion and reduce mechanical loads, with a method involving application and curing of these elements to ensure efficient heat dissipation and reduced material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If encapsulation material is used to enclose cells between cover layers, then cells are protected and connected to cover layers, but material costs increase and production time is delayed due to lamination step

Engineering Contradiction:
Improvecell protection and connectionVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention extracts and eliminates the encapsulation material from the module structure, transitioning from a fully enclosed design to an edge-sealed design with gas filling. This removes the lamination step entirely, reducing production time and material costs while maintaining cell protection through the edge seal and gas pressure system

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces gas filling (pneumatic element) into the module structure to replace the mechanical encapsulation material. The gas provides pressure to hold cells in position and protects them from breakage without requiring lamination, thus eliminating the time-consuming lamination step while maintaining reliability

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Stability of the object's composition

If cells are fixed to cover layers at multiple points, then mechanical stability is improved, but heat dissipation is impeded due to thermal expansion coefficient differences

Engineering Contradiction:
Improvemechanical stabilityVSAvoidheat dissipation
Core Design Contradiction:
Stability of the object's compositionVSTemperature

Solution Approach 1:

The invention segments the fixation system from a continuous or multi-point contact into discrete localized contact elements (LKE). Each LKE provides isolated mechanical support and electrical connection points, allowing the cell surface to remain largely free for heat dissipation while maintaining structural stability through distributed discrete contact points

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by creating localized contact zones (LKE) rather than extensive contact areas. The LKE have specific material properties (conductivity, adhesion) concentrated at precise locations, providing mechanical stability and electrical connection only where needed, while the majority of the cell surface remains thermally active for heat dissipation

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If thin wafers are used to reduce material costs, then manufacturing costs decrease, but the risk of cell breakage increases under mechanical loads

Engineering Contradiction:
Improvematerial costVSAvoidcell breakage risk
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The invention implements beforehand cushioning by introducing a gas-filled structure that provides mechanical cushioning and stress distribution before external loads are applied to thin wafers. The gas pressure creates a supportive environment that prevents direct impact and distributes mechanical stresses, protecting thin cells from breakage during handling and operation

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The invention changes the mechanical parameter environment for thin wafers by replacing solid encapsulation with a compressible gas medium. This parameter change (from rigid to compliant support) allows thin cells to flex and accommodate thermal and mechanical stresses without fracturing, enabling the use of thinner, more cost-effective wafers while maintaining reliability

Inventive Principle:
Principle #35Parameter 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 solution minimizes mechanical loading on photovoltaic cells, reduces manufacturing effort, and enhances heat dissipation by using localized contact elements that allow for flexible connections and reduced material usage, addressing the limitations of prior art while maintaining module stability and efficiency.

Implementation Method 1

differences in thermal expansion between the cell and the cover layer do not lead to critical stresses

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

enhances heat dissipation by using localized contact elements

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Data Source

PatentEP2396827B1Photovoltaic module and method for the production thereof
Publication Date: 2017.12.27 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2396827B1 patent drawingFigure 1
  • EP2396827B1 patent drawingFigure 2
  • EP2396827B1 patent drawingFigure 3

AI summary

The invention relates to a photovoltaic module comprising a first and a second cover layer, an arrangement of photovoltaic cells connected via cell connectors located therebetween and a peripheral seal of the cover layers surrounding the photovoltaic module. The module according to the invention enables a minimization of the mechanical stress, such as by differing thermal expansion coefficients, of the photovoltaic cells. The invention further relates to a method for producing the photovoltaic modules according to the invention.