Task 13 of the PVPS programme aims to support market actors in improving the operation, reliability and quality of PV components and systems. The operational data collected from PV systems in different climates during the project will allow conclusions to be drawn about reliability and the estimated yield.
Task 13 will continue to be needed for the foreseeable future and is critical to the well-being of the PV industry. The reliability of PV systems, modules and components has been and will continue to be an issue for investors and operators. The PV industry continues to undergo rapid change, both in terms of size (global capacity doubles almost every three to four years) and in terms of the use of new technologies (e.g., changing cell thicknesses, introduction of Topcon and SHJ technology and bifacial cells) and new deployment locations and applications, such as floating PV and agricultural PV.
These combined impacts mean that the reliability and performance of PV modules and systems need to be further investigated to ensure that PV remains a good investment, as past performance of similar technologies is not a complete/reliable predictor of future performance of new installations and integrated PV applications.
In 2024, Task 13 published several reports that delve into the current challenges surrounding the reliability and performance of PV modules and systems. Some of the most important are:
Degradation and Failure Modes in New Photovoltaic Cell and Module Technologies
The solar energy industry continues to push the boundaries of efficiency and reliability. However, as innovative photovoltaic (PV) cell and module technologies emerge, they also bring a new set of challenges in durability and performance. A new report titled “Degradation and Failure Modes in New Photovoltaic Cell and Module Technologies,” offers a comprehensive analysis of degradation and failure mechanisms in current photovoltaic (PV) technologies.
Although new technologies bring new challenges, they also lead to positive trends. The report outlines the changes in degradation and failure modes driven by current innovations. The levelized cost of electricity (LCOE) of photovoltaic applications depends on, among other things, the performance, price and durability of the photovoltaic (PV) module. Performance and price can be determined with little effort. Durability is the least known of these three factors. In this report, we evaluate the impact of degradation/failure modes of innovations in the market.
To produce reliable PV modules, all degradation pathways must be understood and mitigated in one solution. There are currently no comprehensive solutions in the literature to address the multiple reliability issues of PSCs. Along with this report Photovoltaic Failure Fact Sheets (PVFS) 2025 are delivered for praxis and field-oriented information for PV planners, installers, investors, inspectors, consultant or insurance companies. The PVFS are available here: Photovoltaic Failure Fact Sheets 2025 – IEA-PVPS
Best Practice Guidelines for the Use of Economic and Technical KPIs
Key Performance Indicators (KPIs) are important metrics used to assess various aspects of photovoltaic (PV) systems, including their long-term performance, economic viability, and carbon footprint. Technical KPIs support data-driven and informed decision-making when optimising PV systems and provide a comprehensive overview of how PV systems operate across different conditions and climates. Different KPIs are commonly employed throughout the entire value chain of PV projects and can be categorised into technical, economic and sustainability aspects. In this work, a set of best practices for handling PV system data to reliably calculate relevant KPIs is discussed. The work is divided into three parts, each addressing different aspects of KPIs, data management, and their mapping potential.
KPIs that are contractually binding carry direct financial implications, while those used in a technical context serve to support the performance assessment of PV plants, and the associated decision-making by stakeholders. The survey showed additionally that while there are certain KPI usage trends per region, a globalised world and market means that there are no strict differences to be seen. Despite the nominal standardisation of contractual KPIs such as the performance ratio and temperature-corrected performance ratio, there are still considerable variations in the data quality routines employed, and consequently, in the calculation of the resulting KPIs.
This report explores key performance indicators in PV systems, focusing on reliable calculation pathways as well as their use to optimise PV performance. Through a review of current best practices and data management techniques, the report highlights the critical role of KPIs in improving PV operations, contractual transparency, and future PV system designs. The report is available here. Technical Key Performance Indicators for Photovoltaic Systems: Challenges and Best Practices – IEA-PVPS.
Performance of Partial Shaded PV Generators Operated by Optimised Power Electronics
Inhomogeneous shading on the PV generator leads to disproportionately high losses. As the potential of PV generation on roofs or façades is to be increasingly utilised in the coming decades, these cases will occur more frequently. The aim here is to provide an overview of the challenges and state-of-the-art technical solutions for partial shading. Current developments in PV engineering show that maximum performance lies in the combination between optimised module placement, the use of modules that are tolerant of shading and optimised power electronics.
Detailed performance analyses have shown that with partially shaded PV generators, conventional string inverters sometimes even achieve better performance in these applications than the market-dominating optimisers. Such meaningful recommendations for high-performance systems can only be made if the realistic losses of the optimisers themselves are considered, which are typically overestimated by 2 %. However, as these annual performance differences between optimizers and string inverters are usually less than 3 % in a market dominated by lightly to moderately shaded PV systems, optimiser manufacturers are obliged to provide realistic efficiency data.
A wide range of additional research work is being carried out to reduce PV shading effects. They range from new variants of sophisticated power electronics for each solar cell, including the control system, to the optimisation of mechanical tracking of single-axis large-scale PV power plants on uneven terrain. The cost-effectiveness for the end customer of PV partial shading can be characterised not only by the higher investment costs for components and installation, but also by the high costs for tradesmen when replacing defective optimisers. When it comes to comparing the probability of failure rates of optimisers due to the higher ambient temperature on the roof compared to string inverters in the building, the experts still must wait for independent studies of service cases during replacement in the field.
The development of new solar cell and PV module designs has never changed as rapidly as in the past few years. Therefore, Task 13 experts from the most important PV manufacturing countries (Asia, Europe and the USA) will describe the challenges, compare sequential and combined test procedures, and potential mitigation solutions to tackle the currently known degradation mechanisms in new PV module technologies.
This will include degradation modes in recent PV technologies as well as Perovskite-based future technologies’ degradation. We will also analyse strategies about how old or defective PV modules may have a second life. As batteries are an important part in PV systems, we start to assess their reliability.
Task 13 experts will focus on novel PV applications. Emerging PV applications are floating PV and Agrivoltaics. Experts will collaborate on energy yield modelling and specific loss mechanism, field performance, and reliability, as well as operation & maintenance challenges and best practices. A general overview and definitions for these integrated PV applications will be given. PV systems with bifacial modules and trackers have a rising market share, as well as systems with module level power electronics. Task 13 will conduct a global survey of PV-tracking technologies to gather information on their tracking algorithms and how they improve bifacial PV performance and system designs. Best practices on performance evaluation are compared and developed. Module level power electronics in the PV system and specifically the effect of shading conditions on the performance are also investigated. Finally, the role of digitalisation in cost and performance optimisation of PV systems and best practices are addressed by the Task 13.
Task 13 will identify extreme weather events including hurricanes, typhoons, blizzards, dust storms, hailstorms and wildfires that impact PV systems, and assess the losses/damage associated with them. Experts will carry out a survey addressing asset owners and other stakeholders regarding the scope of and types of weather-related PV damage (equipment damage, replacement costs, and production losses). The impact of decisions along the value chain of a PV projects (i.e., during design, procurement, engineering, transport, installation, O&M, end of life) will be visualised to define best practice flowcharts for PV projects and contribute towards reducing the risk of PV investments. Data coming from various plant typology and configurations will be benchmarked in terms of techno-economic KPIs.
The overall objective of Task 13 is to provide a common platform to summarise and report on technical aspects affecting the quality, performance, and reliability of PV modules and systems in a wide variety of environments and applications.
By working together across national boundaries, we can all take advantage of research and experience from each member country and combine and integrate this knowledge into valuable summaries of best practices and methods for ensuring PV modules and systems perform at their optimum. Specifically, we aim to:
The quality of Task 13 reports and Task 13 workshops stems from the continued participation of highly motivated PV experts in the field. Like the development of long-term databases for degradation and performance analyses, the collaboration established in previous years will be beneficial to reach out to specific target audiences, e.g., webinar on relevant failure modes in PV applications for PV planning offices, PV testing equipment developers, testing companies, and workshop on digital twinning of PV power plants for asset managers, EPCs and O&M .
Task 13 experts will continue to provide a unique and fundamental analysis of PV components, modules and systems, including new applications such as floating PV and agricultural PV, affecting the reliability and performance of PV systems over their lifetime. With a strong technical focus, the broad global expert participation will enable Task outcomes relevant for stakeholders from PV research and industry. It will contribute to technology requirements, risk mitigation and standardization.
Task 13 is subdivided into three topical Subtasks reflecting the three objectives stated above. The fourth Subtask, dissemination of information and outreach, utilises the output of the three subtasks and disseminates the tailored deliverables produced in the three subtasks.
PV technologies are changing rapidly as new materials and designs are entering the market. These changes affect the performance, reliability, and lifetime characteristics of modules and systems. Such information about new module technology is of great importance for investors, manufacturers, plant owners, and EPCs. The objectives of Subtask 1 are to gather and share information about new PV module technologies and PV plus battery systems that enhance the value of PV by increasing either the efficiency/yield/lifetime or by increasing the flexibility or value of the electricity generated.
Overall Subtask 2 deals with the performance and durability of emerging PV applications as well as with supporting technologies that enable and improve PV applications. This Subtask focuses on the following emerging applications; the integration of PV modules and mounting structures on water surfaces “Floating PV” (ST2.1) and the integration of PV technology into agriculture “Agrivoltaics” (ST2.2). Performance and durability of improved bifacial PV tracking systems (ST2.3) are investigated and best practices developed.
Furthermore, activities on digital integration and digital twinning (ST2.4) as well as on module level power electronics (ST2.5) complete this Subtask. The subtask 2 will provide best practices and guidelines for these emerging PV applications.
It deals with the definition of techno-economic Key Performance Indicators (KPIs) and how to map them in an effective way. This Subtask will focus on the impact in terms of performance due to severe weather events (ST3.1) and climate stressors (ST3.2) to analyse case studies, provide examples of best practices and define guidelines in terms of best technology combination for specific climatic conditions. A dedicated activity (ST3.3) will address the impact of decisions made along the PV value chain, with the aim of defining best practice flowcharts for PV projects and contributing to risk reduction, drawing on results from previous Task 13 phases.
The bottom-up information from ST3.1, ST3.2, and ST3.3 will stream into ST3.4 which is focused on the mapping of the techno-economic KPIs and thus in the visualization of performance related data to provide benchmarks for the PV sector.
