Publications by Hengyu Li | EPFL Graph Search

Related publications (10)

Fast and non-destructive detection on the EVA gel content in photovoltaic modules by optical reflection

Christophe Ballif, Laure-Emmanuelle Perret Aebi, Hengyu Li

Poly(ethylene-co-vinyl acetate) (EVA) has been the dominating material in the photovoltaic (PV) encapsulant market for decades, owing to its superior cost-performance balance. To achieve its desired material properties, EVA undergoes a curing reaction duri ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Compressive-shear adhesion characterization of polyvinyl-butyral and ethylene-vinyl acetate at different curing times before and after exposure to damp-heat conditions

Christophe Ballif, Laure-Emmanuelle Perret Aebi, Hengyu Li, Valentin Chapuis

Photovoltaic (PV) module efficiency and reliability are two factors that have an important impact on the final cost of the PV electricity production. It is widely accepted that a good adhesion between the encapsulant and the different substrates of a PV mo ...

Wiley-Blackwell2012

Thermo-mechanical stability of lightweight glass-free photovoltaic modules based on a composite substrate

Christophe Ballif, Laure-Emmanuelle Perret Aebi, Alessandro Francesco Aldo Virtuani, Hengyu Li, Valentin Chapuis, Ana Cristina Oliveira Martins

Lightweight PV modules are attractive for building-integrated photovoltaic (BIPV) applications, especially for renovated buildings, where the additional load bearing capacity is limited. This work focuses on the development of a lightweight, glass-free pho ...

ELSEVIER SCIENCE BV2018

Modeling potential-induced degradation (PID) in crystalline silicon solar cells: from acceleratea-aging laboratory testing to outdoor prediction

Christophe Ballif, Alessandro Francesco Aldo Virtuani, Laure-Emmanuelle Perret Aebi, Fanny Sculati-Meillaud, Hengyu Li, Eleonora Annigoni

We present a mathematical model to predict the effect of potential-induced degradation (PID) on the power output of c-Si modules in different climates. For the experimental part, we manufacture mini-modules made of two c-Si p-type cells, and use accelerate ...

2016

The effect of cooling press on the encapsulation properties of crystalline photovoltaic modules: residual stress and adhesion

Christophe Ballif, Yun Luo, Hengyu Li, Valentin Chapuis, Laure-Emmanuelle Perret Aebi

A high-quality encapsulation process is crucial to ensuring the performance and long-term reliability of photovoltaic (PV) modules. In crystalline Si technology-based modules, poly (ethylene-co-vinyl acetate) (EVA) is the most widely used PV encapsulant. I ...

Wiley-Blackwell2015

Insights into the encapsulation process of photovoltaic modules: GC-MS analysis on the curing step of Poly (ethylene-co-vinyl acetate) (EVA) encapsulant

Christophe Ballif, Laure-Emmanuelle Perret Aebi, Yun Luo, Hengyu Li

Appropriate encapsulation schemes are essential in protecting the active components of the photovoltaic (PV) module against weathering and to ensure long term reliability. For crystalline cells, Poly (ethylene-co-vinyl acetate) (EVA) is the most commonly u ...

Ismithers2012

Open the Black Box : Understanding the Encapsulation Process of Photovoltaic Modules

Hengyu Li

EPFL2013

In-Situ Monitoring of Moisture Ingress in PV Modules Using Digital Humidity Sensors

Christophe Ballif, Laure-Emmanuelle Perret Aebi, Hengyu Li, Eleonora Annigoni, Fanny Sculati-Meillaud

A new in-situ moisture monitoring technique for photovoltaic (PV) modules is proposed using miniature digital humidity and temperature sensors. The sensors were embedded in three different ethylene-vinyl-acetate (EVA) stacks and proved to be resistant to l ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Optical transmission as a fast and non-destructive tool for determination of ethylene-co-vinyl acetate curing state in photovoltaic modules

Christophe Ballif, Yun Luo, Hengyu Li, Laure-Emmanuelle Perret Aebi

Poly(ethylene-co-vinyl acetate) (EVA) is the primary polymer used for encapsulation of photovoltaic (PV) modules. Its degree of cross-linking (gel content) is taken as a major quality reference. The EVA gel content is normally measured by Soxhlet extractio ...

2013

Effect of Cooling Press on the Optical Transmission through Photovoltaic Encapsulants

Christophe Ballif, Laure-Emmanuelle Perret Aebi, Yun Luo, Hengyu Li

In certain laminators for poly (ethylene-co-vinyl acetate) (EVA) encapsulation process of photovoltaic modules, cooling press (CP) is applied to the module after encapsulation. Here, the effect of CP on the optical transmission through common PV encapsulan ...

Taylor & Francis Inc2015