WG 2: Reliability and durability of PV

This WG’s Chair is dr. Jeffrey Kettle (University of Glasgow) and its Vice-Chair is dr. Mohammadreza Aghaei (NTNU).

Email for contact: Jeff.Kettle-at-glasgow.ac.uk

Objectives of WG 2: 

WG 2 is focused on development of novel methodologies for reliability and durability assessment of PV modules, components and systems in cooperation with leading PV experts in Europe. The main objectives of WG 2 are as the follows: 

  1. To define of reliability and durability metrics for PV modules, components and systems: 
    This considers the differing views of PV stakeholders when describing reliability and durability, as well as differing PV technologies; in this WG, silicon, thin-film and organic PV technologies are considered.  
  2. To identify key data to be collected in order to measure reliability and durability:  
    Identification of relevant data will include assessing large datasets, output power as a function of time and multi-faceted analysis to gauge the output loss, the identification of issue causing a decrease in power output and a correlation of failure modes with climatic conditions. 
  3. To develop a holistic approach of autonomous monitoring and analysis for reliability and durability of PV systems using the potential of a big CKAN data server and the methods of big data analytics (BDA). Additionally, we seek to increase the automation of the monitoring procedure, real-time analysis and decision-making in order to improve the reliability and operational performance of PV systems (see Figure 1 and Figure 2). 
  4. To share knowledge and achievements in the fields of PV reliability and durability via workshops, seminars and joint publications originating from WG2 with a wider community of PV stakeholders and other experts working for insurers, investors, banks, manufacturers, researchers, and consumers. 
Figure 1: Concept scheme of autonomous monitoring and analysis of PV systems


Figure 2: Graphical scheme representing performance and durability research on  organic solar cells.
  1.  Tasks:

Task 2.1: Development of a common description of reliability and durability of PV modules and PV systems by meetings and communications with PV researchers and other experts leading to a shared document to be published on this COST Action’s website.

Task 2.2: Identification of required data and appropriate simulation models to be used in the framework of understanding reliability and durability given the challenges of (i) the often long elapsed duration before the occurrence of both defects and degradation of PV modules in the field (ii) the climate dependency of these effects and (iii) relationships between the manufactured quality of PV module and observed reliability and durability in practice.

Task 2.3: Development of a new concept for automating the monitoring procedure, real-time analysis, and decision-making of PV systems using the potential of the big data bank and the methods of big data analytics (BDA).


D5. Publications of findings originating from WG2 in high-impact journals, conference proceedings and a special issue of an international peer-reviewed journal.

D6. Reports of the WG2 activities (months 12, 24, 36, 48), including the organization of one workshop per year on reliability and durability of PV modules, components and systems.

Conclusions and future outlook:

WG 2 has established a wide network between the WG2’s members from different COST countries to research the methodologies and metrics for reliability assessment, failures analysis, degradation mechanism, performance evaluation, autonomous monitoring, and other related research topics according to the objectives of WG 2 (Aghaei et al., 2020; Atsu et al., 2020; Eskandari et al., 2020; Kettle & Acobsson, 2020).  

An important aspect of WG2 activity has been focused around the definition of reliability metrics and identification of key measures of reliability and durability. The degradation of photovoltaic (PV) systems is one of the key factors to address in order to reduce the cost of the electricity produced by increasing the operational lifetime of PV systems. To reduce the degradation, it is imperative to know the degradation and failure phenomena. By bringing together different European stakeholders, we developed a structure to assess 1) reliability metrics, 2) general reliability issues within PV ‘s and 3) reliability issues in particular PV technologies. By engaging with the community, including research actors from outside of the EU, we were able to produce a report which covered in detail these aspects. Using this report we have prepared to literature review publications one of which has been accepted and one of which is under review. 

The first review article entitled ‘’Reliability and degradation assessment of photovoltaic materials and modules: conventional and emerging technologies’’ was prepared by 17 contributors from 11 COST countries. This was accepted into the prestigious “Renewable and Sustainable Energy Reviews” journal (https://doi.org/10.1016/j.rser.2022.112160).  In this review article, we presented an overview of the state-of-the-art knowledge on the reliability of PV modules. Whilst the most common technology today is mono- and multi-crystalline silicon, this article aims to give a generic summary which is relevant for a wider range of photovoltaic technologies including cadmium telluride, copper indium galllium selenide and emerging low-cost high-efficiency technologies. The review consisted of three parts, which are largly linked to the oibjectives of WG2: firstly, a brief contextual summary about reliability metrics and how reliability is measured. Secondly, a summary of the main stress factors and how they influence module degradation. Finally, a detailed review of degradation and failure modes, which was partitioned by the individual component within a PV module. Building on this knowledge, we proposed strategies to improve the operational lifetime of PV systems and thus, to reduce the electricity cost can be devised.  One of the purposes of this review is to help inform future reliability growth programs in emerging technologies.  


Aghaei, M., Eskandari, A., & Reinders, A. H. M. E. (2020). Autonomous Monitoring and Analysis of PV Systems by Unmanned Aerial Vehicles, Internet of Things and Big Data Analytics. 37th European Photovoltaic Solar Energy Conference and Exhibition

Atsu, D., Seres, I., Aghaei, M., & Farkas, I. (2020). Analysis of long-term performance and reliability of PV modules under tropical climatic conditions in sub-Saharan. Renewable Energy

Eskandari, A., Milimonfared, J., Aghaei, M., & Reinders, A. H. M. E. (2020). Autonomous Monitoring of Line-to-Line Faults in Photovoltaic Systems by Feature Selection and Parameter Optimization of Support Vector Machine Using Genetic Algorithm. Applied Sciences, 10(16), 5527. 

Kettle, J., & Acobsson, J. (2020). Enhancing the stability of Organic Photovoltaics through Machine Learning. Nono Energy, Elsevier

List of participants (status April 2022)

  • Jeff Kettle (University of Glasgow), UK
  • Mohammadreza Aghaei (NTNU), Norway
  • Gernot Oreski (PCCL), Austria
  • Mirjam Theelen, TNO, The Netherlands
  • Istvan Farkas (Szent Istvan University), Hungary
  • Pelin Yilmaz, TNO, The Netherlands
  • Laura Azpilicueta (Evasa), Spain
  • Giorgio Belluardo (EURAC), Italy
  • Guillaume Decleve (SUN7), Belgium
  • Demba Diallo (GEEPS), France
  • Dan Lamb (Swansea University), UK
  • Sanja Lazarova-Molnar (University of Southern Denmark), Denmark
  • Mihaela Girtan (University of Angers), France
  • Ana Rosa Lagunas (CENER), Spain
  • Ivan Marasovic (University of Split), Croatia
  • Bettina Ottersböck (PCCL), Austria
  • Krzysztof Pielichowski (Cracow University of Technology), Poland
  • Marisa di Sabatino (Norwegian University of Science and Technology), Norway
  • Oihana Zubillaga (Tecnalia), Spain
  • Karl Berger (AIT), Austria
  • Divine Atsu (Szent Istvan University), Hungary
  • George Mousdis (National Hellenic Research Foundation), Greece
  • George Georghiu (University of Cyprus), Cyprus
  • Lamprini Papargyri (University of Cyprus), Cyprus
  • Alessandro Virtuani (EPFL), Switzerland
  • Hristina Spasevska (University of Skopje), Macedonia
  • Markus Schubert (Universität Stuttgart), Germany
  • Pascal Kölblin (Universität Stuttgart), Germany
  • Samrana Kazi (Basque center for materials, applications & nanostructures), Spain
  • Shahzada Ahmad (Basque center for materials, applications & nanostructures), Spain
  • Andreas Wade (First Solar), Germany
  • Nikolina Shutinoska (University “St. Cyril and Methodius” Skopje), Republic of Macedonia
  • Caroline Tjengdrawira, (Tractebel Engineering), Belgium
  • Killian Lobato (Universidade de Lisboa, Portugal)
  • V. Kazukauskas (Vilnius University, Lithuania)
  • J. Schmitz (University of Twente, The Netherlands )
  • TJ Jacobbson (Nankai University,  China )

Chair of Working Group 2

Jeff Kettle

University of Glasgow, UK

E-mail: Jeff.Kettle@glasgow.ac.uk

Vice-Chair of Working Group 2

Mohammadreza Aghaei

Norwegian University of Science and Technology (NTNU), Norway

E-mail: mohammadreza.aghaei@ntnu.no