IEA PVPS Task 13 focuses on strengthening international collaboration to improve the reliability and performance of photovoltaic (PV) systems. The Task collects, analyzes, and disseminates information on the technical performance, degradation, and failure modes of PV systems, providing a foundation for their technical assessment and developing practical recommendations to enhance system performance and longevity. The Swiss consortium - comprising SUPSI, CSEM, BFH, OST, and ZHAW - contributes by sharing the latest results from Swiss R&D projects and integrating national expertise into the international dialogue. The dissemination activities aim industry, utilities, and policymakers to remain aligned with international best practices, thereby strengthening the competitiveness of Swiss PV technologies in global market.

A test stand is to be developed from an existing proof of concept for measuring the luminance of PV modules using a foto camera. Compared to existing solutions for determining luminance using the bid- irectional reflectance distribution function (BRDF), the test stand has three main advantages: Firstly, the measurements can be made in the laboratory and outdoors (on a built installation); sec-ondly, the test equipment is inexpensive; and thirdly, very shallow angles (up to approx. 88°) can also be meas- ured. The test stand consists of a profile spotlight, a photo camera with RAW data ex-port option, a mechanical module holder and software based on Matlab or Python, which is yet to be developed in this project. This test bench is used to measure a reduced form of the BRDF.

The main goal of the Subtask A is to explore the role and the potential of BIPV in the context of sustainable buildings and low-carbon construction. The Activity A1 aims to identify and compare the current and potential market share of BIPV in different countries. The analysis gives special attention to the following aspects: (1) A comparison and benchmark of the building materials (on roofs and facades) and their compatibility to be replaced with BIPV standardized BIPV product families, in particular in the context of building retrofit. (2) The adoption of a uniform and common methodology for the definition and calculation of BIPV potential and opportunities. The work will initially consist of identifying best practices and approaches for conducting this BIPV potential analysis and, on this basis, identifying the status and potential of the BIPV market in different countries. This project is about the contribution of HES-SO (HEPIA) to the activities A1 "BIPV market: status, potential and opportunities", A2 "BIPV in the energy / environmental labelling" and A3 "BIPV in our society". This contributions are backed-up through several collaborative research projects (Interreg France-Switzerland, HES-SO, IEA Task 63, SIG Fonds Vitale, Research Council of Norway via NTNU).

The project evaluates the profitability of photovoltaic systems on green roofs in Switzerland. The costs of green roofs and the additional costs for the photovoltaic system are taken into account.

The HyPer-project aims to develop an industrial process for the manufacturing of perovskite-silicon tandem solar cells. HyPer targets the demonstration of textured industrial tandem cells with an efficiency >30% on an area of >250 cm2 thanks to the development of an hybrid two-step deposition method for the perovskite absorber. By optimizing materials, processes and device architectures, another objective will be to extend the operational lifetime of tandems to approach standards reached by mainstream PVtechnologies. HyPer will directly contribute to the EU Green Deal by strengthening the EU PV manufacturing ecosystem to safeguard technology independence and energy security. The last decade has seen a decline in PV manufacturing in Europe due to strong competition from China. With the work planned in HyPer, important foundations will be laid for the industrialization in Europe of the next generation of PV products based on high-efficiency perovskite silicon tandem solar cells.

Switzerland should multiply its photovoltaic (PV) capacity by at least 6 times over the next 25 years (2050). Accurate performance assessment and optimized design are essential to maximize PV yield. By analyzing the data of hundreds of PV plants, the project aims at triggering a learning process. Focus will be dedicated to: (1) reducing uncertainties in performance loss estimates; (2) increasing statistics by enlarging the base of analyzed PV projects; (3) develop data-driven failure identification and classification algorithms (FDD). Compared to the previously SFOE-funded ASSURed-PV project, these major novel activities are planned: expansion of FDD algorithms to include irreversible failure modes, extend the scope of the analysis from small to largescale PV plants, increasing statistics.

An outdoor measurement method for PV modules is to be developed. The measurement method has the following properties: (1) Thanks to several sensors or the possibility of repositioning sensors, it is more accurate than comparable measurement methods. (2) The measurement method can estimate the measurement uncertainty or the accuracy of the individual measurements. The measurement accuracy is particularly dependent on the weather conditions and the temporal and spatial homogeneity of the irradiation during the measurement. An algorithm is to be developed for a measuring device (IV Curve Tracer, IVCT) developed by the PV laboratory at BFH, which will be used to calculate the measurement accuracy and display it together with the measurement results. The measurement accuracy can be increased by adjusting sensor positions (reference cells) and repeating the measurement. In principle, the measuring software should be able to be used in any characteristic curve measuring device In this project, it will be demonstrated by means of the IVCT of BFH. The measurement method is to be used in particular in the re-use sector. It should become the most cost-effective method currently available for evaluating the performance of PV modules in the field.

The project CREATE aims to extend the knowledge of energy yield and degradation rates of new PV mainstream technologies for different mounting configuration, which is crucial to reduce the risks of underperforming systems. The results of previous outdoor measurement campaigns initiated by SUPSI in 2021 highlighted criticalities on some of the mainstream technologies, as early-stage fail-ures or degradation rates exceeding power warranties which requires further investigations and longer time series data to discern between the different degradation modes and to correlate labora-tory testing to field performance data. CREATE will therefore extend the measurement campaigns for other 3 years by putting more emphasis on the analysis of specific degradation mechanisms oc-curring in heterojunction (HJT), tunnel oxide passivated contact (TOPCon) and back-contact (BC) technologies, which are in mass production now (TOPCon) or have been identified in the industrial roadmaps as the most promising for the next technology transition. The analysis will be supported by accelerated indoor tests aiming in explaining the field performance and observed degradation pat-terns. Energy Rating assessments according to IEC 61853 will be performed in the laboratory and compared to field data to better understand their accuracy and applicability for Switzerland and BIPV systems and to demonstrate the impact of climate or application specific energy yield assessments. The impact of climate or application specific degradation rates and its impact on lifetime energy rat-ing will be further assessed. Supporting measures for the introduction of a new European energy label for the evaluation of PV modules will be pursued within the project in close cooperation with international expert groups working in this field.

The goal of BESTOBOT is to develop stable ultra-high efficiency (>30%) solar cells with a reduced carbon footprint and commer-cially viable process to contribute to lowering the levelized cost of photovoltaic energy. To do so, the project leverages the exper-tise of the research team in fabricating high-efficiency PV devices by understanding the fundamental mechanisms at play, in particular the interaction between the top and bottom cells forming tandem devices. A special focus will be put in ensuring the cost-effectiveness of the developed processes while avoiding the use of critical raw materials.

Subsidies for facade PV systems were significantly increased in 2025, and the Electricity Act means that they no longer require a building permit. Despite these simplifications, compliance with all applicable regulations, particularly in the area of fire protection, remains crucial. With regard to fire protection for PV facades, the present project aims to develop a recognized state-of-the-art paper (STP) for low- and medium-rise buildings. To this end, the fire behavior of PV modules will be researched and the corresponding test standards developed.

In summer 2020, the 410 kWp PV system at the Albigna dam at 2165 m above sea level was the first large-scale high-Alpine system to be commissioned, and another will be commissioned in 2022 with the system at Lago di Lei. Due to their location, they are exposed to extreme meteorological stresses. By analyzing the yield data, periodically measuring the module output, taking thermal images and checking the general condition of the system, the aim is to gain insights into the long-term reliability of systems at comparable locations.

The aim of PV-GOAL is to promote the sustainable and efficient growth of solar energy in Switzerland by by providing access to private, commercial and industrial solar industrial solar installations for the automatic detection of outages and energy energy deficits using advanced digital twin monitoring technology. twin monitoring technology. The FHNW, in collaboration with Solextron AG to develop algorithms and a deployable cloud cloud monitoring tool that is capable of carrying out fault detection to carry out fault detection and thus, for the first time, make solar digital twin twin technology available to small and medium-sized installers for the first time. installers. Translated with DeepL.com (free version)

The realisation of alpine PV plants faces a special challenge compared to plants on the Swiss Plateau. In the Alps, wind loads are higher, snow drifts occur, temperature cycles are faster and temperature amplitudes are larger, and at the same time the irradiation of energy-rich UV light is increased. This results in additional requirements for the module design, the supporting structure, the system technology, the maintenance and the operational management of such systems. In this project, scientific questions on the following topics will be addressed: (1) mounting system and influence of the mounting system on PV modules; (2) selection of suitable PV modules for alpine use; (3) optimisation of the system design to achieve maximum yields, especially in the winter months; (3) selection of suitable outdoor measurement technology to assess systems and modules; (4) general system aspects (selection of components, system design for measurements on installations); and (5) quality monitoring of installations. Within the framework of the project, not all of these issues will be addressed and solved from scratch. In addition to measurements, analyses and simulations, which are newly carried out within the framework of this project, information from parallel running projects and experiences from planned and realised projects are also incorporated. This leads to a far-reaching and comprehensive state of knowledge in the field of alpine photovoltaic systems. The PV competence centres of the universities of applied sciences ZHAW, BFH, SUPSI and OST have joined forces to form a joint consortium for this purpose, in order to be able to answer the scientific questions in the field of alpine PV systems and the additional questions posed to universities of applied sciences by project developers in a more competent and efficient manner within the framework of this research project. The aim is to intensify the cooperation between this consortium and various implementation partners and to make the results of the cooperation, insofar as they are not confidential, available to the public. The rapid exchange of knowledge and experience between the individual project teams is a key to faster and more efficient implementation of Alpine PV projects.

Perovskite-Silicon tandem solar cells are a promising combination to improve upon standard silicon photovoltaics, and the efficiency of this technology is already in a market-relevant range. However, the stability of these devices, limited by the stability of the perovskite top cell, is hindering imminent commercialisation. The stability of the top cell is impacted by the composition, the fabrication method and within the device by the adjacent layers. All three of these aspects create an enormous space of possibilities for fabrication and cannot be screened by traditional methods. PERSISTARS aims to develop methods to efficiently screen this multidimensional fabrication space by combining automation with a computational backbone to make use of Bayesian inference to navigate the high-dimensional space effectively. Furthermore, to date there are no reliable estimates as to how accelerated indoor ageing protocols relate to outdoor measurements, i.e., the acceleration factor of combined stress tests is mostly unknown. Using the newly developed tandem devices with predicted higher stability, PERSISTARS will aim at quantifying acceleration factors for single-junction and tandem devices by comparing extensive in- and outdoor measurements.

Plug & Play photovoltaic systems are becoming increasingly popular. Because they are not installed systems but consumer products, their regulatory treatment is challenging. The "Plug & Play PV Systems" project aims to address the most important issues relevant to Switzerland. Because this requires many different stakeholders, the project group consists of Meteotest (calculating the potential for Plug & Play PV systems), VSE and BKW (assessing the systems from the grid operator's point of view), ESTI, electrosuisse and VSEK (assessing the safety of Plug & Play systems), as well as the BFH, which is leading the project and answering normatively unresolved safety questions in laboratory tests. The PV industry will be represented in the project by three partners with many years of experience with Plug & Play PV (Energie Genossenschaft Schweiz, hassler energia, Solarblitz). The aim of this project is, on the one hand, to propose pre-normative rules and, on the other hand, to draw up proposals for the regulation of installations from the point of view of VSE, electrosuisse and ESTI, well consulted in the consortium.

The IEA PVPS Task 16 started in July 2017 and will end in June 2020. It is led by the Swiss company Meteotest AG. This offer includes the leading of the Task from July 2020 till June 2023 for the first extension period. The activities of the Tasks will be updated. New topics will include spectral models, albedo data for enhanced modelling of bifacial modules and firm PV produc-tion. The objective of the Task is to write a new version of the solar resource handbook.

Switzerland participates in the IEA PVPS Task 12 on “PV Sustainability”. The Swiss contribution fo- cuses on the life cycle assessment of PV systems. The proposed activities 2023 – 2026 include peri- odic LCI data updates based on key parameters, contributions to methodology guidelines and other activities, the participation in Task 12 meetings and the writing of an annual report.

The SmallFlex Goms project aims first to confirm the flexibility of the KWGO plant identified in the SmallFLEX project with a monitored long-term operation of these new flexible modes (WP1). Applying the methodology developed for KWGO, an exhaustive inventory of small hydro power plants in the Goms region will be carried out to define selection criteria (WP2). For the most promising sites, a hydraulic analysis of the technical limits of these plants will be carried out (WP3), as well as a shortterm prediction of the inflow and solar potential (WP4). In parallel, the risk of air entrainment will be evaluated (WP5) before carrying out on-site test campaigns to confirm these results (WP6). The interest of integrating flexible run-of-river or pumped storage plants in a Virtual Power Plant (VPP) associated with other sources of electricity generation and storage in the vicinity of the plant will be evaluated (WP7). Finally, a business model will be developed to evaluate the economic gains from the implementation of these new operating modes (WP8).

Aim of this project is to define a new methodology for quantitative and timely detection of defects and failures in PV modules through image analysis in combination with the use of artificial intelligence algorithms and their correlation with module performance losses. The basis of this analysis is the use of a unique ultra-high resolution multispectral camera with UV to IR sensitivity, appropriate filters and lights setup. To achieve the project goals, a methodology for automatic identification of failure modes at the cell level will be implemented using Convolutional Neural Networks (CNNs). The results of the project will have a direct impact on future defect tracking methodology, both in research labs, manufacturing and operational environments, allowing a quantitative and measurable way to record the evolution of module performance.

Near-infrared-transparent wide-bandgap (1.65-1.8 eV) perovskite solar cells hold great promise for tandem application. However, the most efficient wide-bandgap perovskite solar cells are primarily fabricated by spin-coating followed by thermal annealing, which is difficult to scale up with high throughput. In this project, we aim to overcome this challenge by developing a new high-speed manufacturing process that combines slot-die coating and photonic curing methods to scale up the perovskite and charge transport layers. Basic building blocks of processes e.g. ink formulation, drying and subsequent heating for good structural and electronic quality layers and interfaces will require basic investigations and combinatorial optimization. Upon successful development these methods can be applicable on different substrates and high throughput low cost manufacturing of large-area perovskite single-junction and perovskite-based tandems, including perovskite-silicon, perovskite-CIGS, and perovskite-perovskite. Tandem devices yielding higher power and lower cost will support enhanced deployment of PV for variety of applications, consequently reducing the CO 2 footprint and thus contributing towards net zero emission targets for sustainable future.

The vision of SUNSHINE is to demonstrate a new inverter topology for photovoltaic applications, the so called Adjustable Hybrid Switch inverter (AHS). SiC based inverters offers superior energy conversion efficiency in comparison to its Si counterpart, while unfortunately, it offers also incompatible high costs for PV applications. In the AHS topology, a SiC MOSFET is connected in parallel to a Si IGBT for the inverter switch, and the devices are sequentially switched based on current demand. In this project we aim to demonstrate that this topology is able to both reduce costs of SiC inverters while offering comparable efficiency. The performance will then be benchmark against the results in full Si and full SiC inverters investigated in the Task G of PECTA. As such, SUNSHINE intends to disrupt PV technology, by introducing a cost effective inverter with superior energy conversion.

The COMET project aims at increasing the overall sustainability of PV energy by developing copper metallization processes for current ptype and future n-type solar cells and modules. COMET will demonstrate a lean copper electroplating process for PERC and TOPCon solar cells allowing the simultaneous metallization of the front and the rear sides up to M6 wafer format without ghost plating. Innovative and reliable interconnections based on electrically conductive adhesives will also be demonstrated. In addition, COMET will unveil the physical phenomena ruling the poly-Si/Cu contact formation, including barrier layers between poly-Si and copper, and identify the materials and process parameters yielding the lowest contact resistivity without damaging surface passivation. Finally, COMET will demonstrate the reliability and the cost-effectiveness of Cu-metallized solar cells up to mini-modules and perform both standard degradation tests and outdoor accelerated ageing to pinpoint their main failure modes so as to increase the validation and the bankability of Cu metallization as a sustainable replacement for Ag.

Achieving the ambitious targets of decarbonizing the European economy requires a huge effort. Integration of PV into existing infrastructure is one of the main pillars to reach the targets for renewable electricity, especially for countries where there is not enough free land to build largescale PV plants: either because they are densely populated (Netherlands, Belgium) or mountainous (Austria, Switzerland). Doing this successfully requires simultaneous optimization of energy yield and cost, but also module weight, aesthetics, circularity, reliability, and safety. DELIGHT project brings together expertise in all these areas and will develop highly attractive, and unique solutions for the integration of PV, to enable energypositive buildings. The DELIGHT consortium aims to design, manufacture, and evaluate sustainable lightweight composite PV modules for easier integration into existing infrastructure, with a special focus on increased safety, optimized aesthetic, and constructive integration. The main targets are: (1) Reducing the module weight of the PV modules and the construction system, achieving a weight target for modules of <6 kg/m2 (glass-free) and <7 kg/m2 (design with front glass) for frameless fullsize lightweight modules. (2) Fulfilling the demands for aesthetic integration by use of novel, colored components, and coatings, alternative reliable PV modules easily to integrate into buildings and infrastructures. (3) Optimizing the electrical module design in respect to shade tolerant module topologies, improving performance, safety, and reliability under partial shading (module shut-down; disconnection of damaged substrings; reduction or elimination of hot-spots). An additional crosssectional objective is to increase the overall sustainability of the lightweight modules and their components. Specific targets are the replacement of fluoropolymer front sheets, with solutions based on coated polyester films or the use of recycled PET for the honeycomb structures. DELIGHT will bring these new concepts and solutions (e.g., coloring, composite back sheet, mounting solutions, polymer front sheet, etc.) to sufficiently high TRL (6-7), improving ecodesign, while retaining performance, quality, and reliability. The project aims at the realization of a sustainable and competitive PV product, entirely designed, manufactured, and optimized in the EU, to contribute to the European market with high quality and trust.

The present project has the following content: In cooperation with the Agroscope Conthey Research Station and the Bern University of Applied Sciences as well as suppliers of solar systems, the suitability of three different Agri-PV systems (1 static system and 2 dynamic technologies) compared to the standard system of raspberry cultivation under weather protection used today is being researched for practical use. The objectives of this on farm "Agri-PV living lab" are to demonstrate the suitability of the PV system as a combination with weather protection or as weather protection, to demonstrate the benefits of shading by a PV system for positive yield development, and to develop a cost-effective and efficient Agri-PV system for widespread application in agriculture. Approximately 500 MWh of solar electricity will be produced, meeting the electricity needs of approximately 110 households. Some of the electricity can (possibly) be sold to neighboring industries. Our plant should contribute to the creation of crop protection with production of sustainable electricity by other farms through an Agri-PV plant.

In the mountainous countries of Switzerland and Austria, the availability of open spaces for ground-based PV systems is limited, which is why PV systems also have to be installed as integrated solutions in buildings, infrastructures, multi-purpose applications and alpine regions. PV systems operating in such “unconventional” environments must withstand different and enhanced stresses than those developed for large-area field installations in moderate climates. Depending on the application and environmental conditions, additional loads beyond the limits of IEC standard tests (higher UV loads for the alpine environment or increased thermal loads for BIPV etc.) can accelerate the degradation of PV modules. In order to accelerate the spread of PV systems in demanding environments, it is necessary to select stress-optimised materials, components and a module architecture that can withstand the increased loads and prevent early/premature module failures and unexpected performance losses. To enable efficient and fast product development, advanced tools for early quantitative detection of potential failures/degradation modes (induced by increased stress impact) are required. PV-DETECT aims to develop a method for early detection of failures through advanced reliability testing combined with sensitive degradation detection. This advanced methodology provides PV module manufacturers with a tool to accelerate the development of PV modules designed for specific environmental conditions or applications by a factor > 3 (more reliable results in much shorter testing times). The comparative assessment will allow to identify the weaknesses of specific module architectures and bill-of-material approaches at a very early stage (few weeks) of the development phase. Based on these results, it will be possible to summarise the possibilities of using new designs and materials to increase the system´s resilience to extreme stress conditions.

PV facades are an important building block for the realization of the Energy Strategy 2050. In the case of PV facades on very high buildings (>30 m high-rise), the fire department can no longer reach the source of the fire. Such PV facades and their components must be approved in the canton of Berne by the Berne building insurance GVB. For this, the components would have to be RF1 (non-combustible). This is not the case for a PV module with its foils, etc. The approval and realization of such projects was therefore time-consuming, laborious and caused additional costs. In order to regulate this in the future, the GVB has initiated the present project. On the basis of the two facades in Bern at Holenackerstrasse 65 (2022/ 2023) and 85 (2023/ 2024), protection goals and measures to fulfill "fire safety" are to be defined. With this preliminary work, two facades will be realized. This will be explained in a guideline that will be made available to building owners and stakeholders in and outside the canton of Bern.

OpenGIS4ET successfully delivered Citiwatts 3.0, a comprehensive open-source energy planning platform that advances the green transition across heating, cooling, mobility, and sector coupling domains. Building on the H2020 Hotmaps foundation, the project reached TRL-8 by providing default data for all EU27 nations, UK, Norway and Switzerland at national and local levels, enabling energy planners and public authorities to efficiently analyze, model, and map solutions to meet their energy demands. The platform features a robust DevSecOps development framework with continuous security analysis through SonarQube integration, responsive design compatibility across desktop and mobile devices, and comprehensive two-factor authentication through Keycloak services. A secure public API enables external system integration, while advanced session management allows users to maintain multiple calculation results per module, transforming the tool from single use to a comprehensive analysis workspace. Three sophisticated calculation modules were developed and validated through real-world case studies: The EV-Mobility tool provides Vehicle Kilometer Travelled mapping with charging behavior modeling across four scenarios (home, workplace, points of interest, and home office charging), coupled with photovoltaic production potential analysis. The District Heating and Cooling tool addresses temperaturelevel optimization with economic feasibility assessment. The Sector Coupling tool integrates electrical, heating, and transport systems through connection with EnergyPLAN, enabling comprehensive flexibility analysis for multi-sector energy planning.